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ROYAL GOVERNMENT OF BHUTANMINISTRY OF WORKS & HUMAN SETTLEMENT

DEPARTMENT OF ROADS, DESIGN DIVISION

CONSTRUCTION OF BY-PASS ROAD AT YESHEYGANGCHHU BRIDGE

ON TRONGSA – GELEPHU HIGHWAY TECHNICAL SPECIFICATION& Performance

RequirementsDATE JUNE 2015

Prepared by Bridge Design Section, Design Division, DoR, Thimphu

TECHNICAL SPECIFICATION

INTRODUCTION

1. This Specification should be read in conjunction with the other documents which are The Tender, the Conditions of Contract and, The Drawings.

3. This specification is split into Sections 1 to 5, which are identified on the following pages. Each section is separated into specific sub sections with work descriptions, specifications of materials, construction methods, methods of measurement and items for payment.

4. This Technical Specification is an integral part of the contract and the Contractor is required to comply fully with all aspects of this Specification.

5. The Contractor is responsible for ensuring that the necessary tests and measurements are carried out in order to ensure that the work complies with the Specifications. The Contractor shall give a minimum of 24 hours notice in writing to the Engineer for each item of work to be covered or buried. The contractor should make due allowance in his program of work for all necessary testing of the works in accordance with these Specifications. Any work not undertaken in accordance with these conditions may be rejected by the Engineer.

6. The term “Engineer” used in this specification and other sections of this tender document shall mean a person with degree or diploma in engineering from any recognized Institute or University of Engineering who shall supervise and be in charge of the work, and act on behalf of the Employer/Client.

Construction of Bypass Road at Yesheygangchhu Page 1


TECHNICAL SPECIFICATIONS

CONTENTS:

ABBREVIATIONS

SECTION 1 GENERAL AND SITE FACILITIES

SECTION2 EARTHWORK

SECTION 3 CONCRETE WORKS & OTHER RELATED WORKS

SECTION 4 ROAD WORK

SECTION 5 DAY WORK



ABBREVIATIONS

AASHTO AMERICAN ASSOCIATION OF STATE HIGHWAY AND TRANSPORTATION OFFICIALS

ACV AGGREGATE CRUSHING VALUE

ASTM AMERICAN SOCIETY OF TESTING AND MATERIALS

BS BRITISH STANDARD

CBR CALIFORNIA BEARING RATIO

DOR DEPARTMENT OF ROADS

HWL HIGH WATER LEVEL

IS INDIAN STANDARD

LWL LOW WATER LEVEL

MLSS MEMBERS OF LOWER SERVICE STAFF

MSL MEAN SEA LEVEL

PVC POLYVINYL CHLORIDE

ROW RIGHT OF WAY

TS TECHNICAL SPECIFICATION

BoQ BILL OF QUANTITY

IRC INDIAN ROAD CONGRESS



TABLE OF CONTENT

1.0 GENERAL AND SITE FACILITIES 13

1.1 GENERAL 13

1.1.1 Scope of Work 13

1.1.2 Site Acquaintance 14

1.1.3 Specifications 14

1.1.4 Reference to Bureau of Indian Standards Codes & Other Codes 14

1.1.5 Dimensions & Levels 14

1.1.6 Notice of operation 14

1.1.7 Work program 14

1.1.8 Time Schedule 14

1.1.9 Drawings 15

1.1.10 Sub-Contracting 15

1.1.11 Compliance 15

1.1.12 Supply of Materials 15

1.1.13 Ordering Materials 15

1.1.14 Material Quality 16

1.1.15 Equipment & Facilities 16

1.1.16 Work Site Register (Site Order Book) 16

1.1.17 Area for the Contractor 16

1.1.18 Unit of measurement 16

1.2 SITE INSTALLATION 17

1.2.1 Establishment of temporary infrastructure and facilities 17

1.2.1.1 Contractor’s site office 17

1.2.1.2 Labor Camps 17

1.2.1.3 Waste Management 17

1.2.1.4 Material Storage 18



1.2.1.5 Temporary Drainage System 18

1.2.1.6 Site Water Supply and Electricity 18

1.2.2 Additional facilities to be provided 18

1.2.2.1 Survey Equipment 18

1.2.2.2 Sign Boards 19

1.2.3 Testing of Materials 19

1.2.3.1 Contractor’s Site Laboratory 19

1.2.3.2 Materials Testing by Independent Laboratories 21

1.2.3.3 Staff for Material Testing 21

1.2.3.4 Sampling and Testing 21

1.2.4 General Contractor’s Obligations 22

1.2.4.1 Insurance 22

1.2.4.2 Safety measures and penalties 22

1.2.4.3 Protection of the Environment 22

1.2.4.4 As-Built Drawings 23

1.2.5 Maintenance and demobilization 23

1.2.6 Measurement and Payment 23

1.2.7 Pay Item 23

2.0 EARTH WORK 24

2.1 CLEARING AND GRUBBING 25

2.1.1 General 25

2.1.2 Clearing jungle 25

2.1.2.1 Measurements 25

2.1.2.2 Rates 25

2.2 Felling of Trees 26

2.2.1.1 Measurements 26

2.2.1.2 Rate 26

2.2.2 Pay Items 26

2.3 EXCAVATION AND BACKFILL FOR STRUCTURES 27

2.3.1 General 27



All kinds of soil 27

All kinds of rocks 27

2.3.1.1 Setting out 27

2.3.1.2 Stripping and storing topsoil 28

2.3.2 Excavation 28

2.3.2.1 Methods, tools and equipment 29

2.3.2.2 Rocks excavation: 29

2.3.2.3 Blasting 29

2.3.2.4 Disposal of Excavated Material 29

2.3.2.5 Pumping and Bailing 30

2.3.2.6 Backfilling 30

2.3.3 Measurements 30

2.3.4 Payment 31

2.3.5 Pay Items 31

3.0 CONCRETE & OTHER RELATED WORKS 32

3.1 CONCRETE FOR STRUCTURES 33

3.1.1 Standards 33

3.1.2 Description 33

3.1.3 Materials 33

3.1.3.1 Specifications for Materials 33

3.1.3.2 Testing of Materials 36

3.1.3.3 Composition of Concrete 38

3.1.3.4 Control of Concrete Quality 40

3.1.4 Construction Methods 43

3.1.4.1 General 43

3.1.4.2 Care and Storage of Concrete Materials 43

3.1.4.3 Preparations before Casting 43

3.1.4.4 Measuring Materials 44

3.1.4.5 Mixing Concrete 44

3.1.4.6 Handling and Placing Concrete 47

3.1.4.7 Removal of Scaffolding and Formwork 49

3.1.4.8 Repair of Concrete 49



3.1.4.9 Depositing Concrete under Water 49

3.1.4.9.1 Cleaning Up 50

3.1.5 Measurement 50

3.1.6 Payment 50

3.1.7 Pay Items 50

3.2 Formwork and Scaffolding 50

3.2.1 Formwork 51

3.2.1.1 Surface Treatment for Shuttering 52

3.2.1.2 Camber 53

3.2.2 Approval of Scaffolding and Formwork 53

3.2.3 Removal of Form Work 53

3.2.4 Measurements 54

3.2.5 Payment 54

3.2.6 Pay Items 54

3.3 RCC hume pipes 54

3.3.1.1 Scope 54

3.3.1.2 Material 54

3.3.1.3 Placement 54


3.3.3 Payment 54

3.3.4 Pay items: 55

3.4 Stone Work 55

3.4.1 Scope 55

3.4.2 Materials 55

3.4.3 Stone 55

3.4.4 Cement Mortar 55

3.4.5 Construction 56

3.4.6 General 56



3.4.7 Concrete Capping 57

3.4.8 Pointing 58

3.4.9 Weep holes 58

3.4.10 Ashlar 58

3.4.11 Block-in-Course 58

3.4.12 Square Rubble- Coursed or Broken Courses 59

3.4.13 Random Rubble - Coursed or Uncoursed 59

3.4.14 Dry Random Rubble 59

3.4.15 Composite Random Rubble 60

3.4.16 Stone Pitching 60

3.4.16.1 General 60

3.4.16.2 Material 60

3.4.16.3 Mock-Up 60

3.4.16.4 Construction 60

3.4.16.5 Stone Soling 60

3.4.16.6 Test & Standard of Acceptance 60

3.4.16.7 Measurement 61

3.4.17 `Payment 61

SECTION 4 62

4.0 ROAD WORK 62

4.1 EXCAVATION FOR FOUNDATION, DITCHES, PAVEMENT, SLOPES, LANDSLIDES 63

4.1.1 Excavation for Ditch, Clearing of Existing Drains and Channels 63

4.1.1.1 Excavation (Scarification) for Pavement 63

4.1.1.2 Excavation for Slopes and Removal of Landslides 63

4.1.2 REFILLING OF FOUNDATION PITS AND TRENCHES, REMOVAL OF SUPPORTS AND FILLING TO STRUCTURES 64

4.1.3 Materials 64

4.1.3.1 Pervious/Graded Backfill 64



4.1.3.2 Common Backfill 65

4.1.4 Method of Filling 65

4.1.5 FORMING OF EMBANKMENT AND OTHER AREAS OF FILL 65

4.1.6 COMPACTION OF EMBANKMENTS AND OTHER AREAS OF FILL/BACKFILL 67

4.1.7 COMPACTION TRIALS 70

4.1.8 BENCHING 71

4.1.9 FINISHING OF SLOPES 72

4.1.10 EARTHWORKS TO BE KEPT FREE OF WATER 72

4.1.11 WATERCOURSES 72

4.1.12 FILLING EXISTING WATERCOURSES 73

4.1.13 PROCESS CONTROL 73

4.1.14 MEASUREMENT 73

4.1.15 PAYMENT 74

4.2 PROCESS CONTROL TESTING & TOLERANCES 74

4.3 ADVERSE WEATHER WORKING 78

4.3.1 USE OF SURFACES BY CONSTRUCTION TRAFFIC 78

4.3.2 CARE OF WORKS 79

4.3.3 MEASUREMENT AND PAYMENT 79

4.4 SUBGRADE 79

4.4.1 SCOPE 79

4.4.2 DEFINITIONS 80

4.4.3 PREPARATION AND SURFACE TREATMENT OF FORMATION (SUBGRADE) 80

4.4.4 RIPPING OFF EXISTING BITUMINIOUS SURFACE USING EXCAVATOR 82

4.4.5 SCARIFYING OF EXISTING BITUMINIOUS SURFACE 82




4.4.7 PAYMENT 83

4.4.8 Payment Item 83

4.5 GRANULAR SUBBASE (GSB) 83

4.5.1 GENERAL 83

4.5.2 SOURCES OF MATERIALS 83

4.5.3 MATERIAL REQUIREMENTS AND POTENTIAL PROCESSING 84

4.5.4 COMPACTION TRIALS 84

4.5.5 PREPARING UNDERLYING COURSE 85

4.5.6 LAYING AND COMPACTION 85

4.5.7 PROOF ROLLING 85

4.5.8 SETTING OUT AND TOLERANCES 86

4.5.9 DRAINAGE OF SUBGRADE AND SUBBASE 86

4.5.10 TESTING 86


4.5.12 PAYMENT 87


4.6 BASE COURSE 87

4.6.1 WET MIX CRUSHED STONE BASE 87

4.6.2 General 87

4.6.3 Materials 87

4.6.4 Crushing, Screening and Mixing 89

4.6.5 Construction Operations 89

4.6.6 Proof Rolling 91

4.6.7 Setting Out and Tolerances 92



4.6.8 Rectification of Surface Irregularity 92

4.6.9 Testing 92


4.6.11 Payment 93


SECTION 5 94

5.0 DAYWORKS 94

5.1 General 94

5.2 Daywork Labor 95

5.3 Daywork Materials 95

5.4 Daywork Plant 96



LIST OF TABLES

Table 3.1-1Grading Requirements Coarse Aggregate.............................................................40

Table 3.1-2Grading Requirements for Fine Aggregate............................................................41

Table 3.1-3 Concrete classes....................................................................................................43

Table 3.2-1 Removal of Form Work........................................................................................64

Table 5.1-1Grading Limits of Pervious Backfill......................................................................81

Table 5.1-2Depth and Degree of Compaction.........................................................................84

Table 5.1-3 Compaction Requirements....................................................................................84

Table 5.2-1Tolerances for Level and Surface Regularity........................................................92

Table 5.5-1Grading Envelope for Granular Subbase.............................................................101

Table 5.5-2 Granular Subbase - Minimum Testing Frequency..............................................103

Table 5.6-1Physical Requirements of Coarse Aggregates for Wet Mix Base Course...........105

Table 5.6-2Grading Requirements of Aggregates for Wet MixBase Course........................105

Table 5.6-3Minimum Testing Frequency...............................................................................109

Table 5.7-1Temperatures Ranges for Heating and Spraying Binders....................................111

Table 5.7-2Maximum Addition of Paraffin...........................................................................112

Table 5.7-3Viscosity Requirement and Quantity of Bituminous Primer...............................115

Table 5.7-4Temperature for Storage......................................................................................117

Table 5.7-5Minimum Testing Frequencies............................................................................118

Table 5.8-1Physical requirements for coarse aggregate for DBM.........................................119

Table 5.8-2Grading of filler material.....................................................................................120

Table 5.8-3Composition of DBM pavement layers...............................................................120

Table 5.8-4Requirements for dense graded bituminous macadam........................................122

Table 5.8-5Minimum percent voids in mineral aggregate (VMA)........................................122

Table 5.8-6 Permissible variations from the job mix formula...............................................123

Table 5.9-1Physical Properties for Coarse Aggregates for Asphalt Concrete.......................136

Table 5.9-2Gradation Requirements of Aggregate for Asphalt Concrete..............................137

Table 5.9-3Requirements for Asphalt Concrete.....................................................................137

Table 5.9-4Minimum Testing Frequency...............................................................................140



SECTION 1

1.0 GENERAL AND SITE FACILITIES



1.1 GENERAL

1.1.1 Scope of Work

The Scope of work covered by his specifications is to execute the construction of By-pass Road at Yesheygangchhu Bridge on Trongsa – Langthel Highway

1.1.2 Site Acquaintance

The Contractor shall be deemed to have made himself / herself fully acquainted with the full nature of the work, the location & character of the bridge site & means of access to the site, including any traffic restrictions imposed. The construction site is an area within 5kms radius of the location of the bridge.

1.1.3 Specifications

The work shall be executed in accordance with the technical specifications, the drawings, the Bill of Quantities & the instructions issued by the Client from time to time. Wherever these specifications are found wanting in anyway, the latest edition of standard specification for Bridges as approved by the Client shall be followed.

1.1.4 Reference to Bureau of Indian Standards Codes & Other Codes

The Standard Specifications & Codes of Practices explicitly referred to in these Specifications or other related standard codes etc. shall be of latest editions, current at the time of tendering including all amendments published before that date.

1.1.5 Dimensions & Levels

All dimensions & levels shown on the Drawings shall be verified by the Contractor at the site & he/she will be held responsible for the accuracy & maintenance of all dimensions & levels. Figured dimensions are in all cases to be accepted & no dimensions shall be scaled. Large scale details shall take precedence over small scale drawings. In case of discrepancy the Contractor shall ask for clarifications from the Engineer before proceeding with the work.

1.1.6 Notice of operation

The Contractor shall not carry out important operations without the consent in writing of the Engineer.

1.1.7 Work program

The Contractor shall submit to the Engineer before commencement of the work, for his approval, a detailed program in the form of bar chart/Microsoft project etc. The submission & approval of such program shall not relieve the Contractor of any of his duties or responsibilities under the Contract.



1.1.8 Time Schedule

The Contractor shall follow the project master schedule & detailed activity schedule submitted after signing the contract. The contactor may submit minor changes on schedule to the Engineer for approval whenever necessary.

1.1.9 Drawings

The Contractor will receive free of cost one complete set of all drawings necessary to complete the Work & is to include in his Tender for any additional copies of drawings required by him. One copy of the full set of drawings shall be retained at the site.

1.1.10 Sub-Contracting

Should the Contactor consider it necessary to sub-contract any part of his work, the Sub-Contractor & the scope of the work proposed to be sub contracted has to be approved by the Engineer/Client. It will be the responsibility of the Contractor to ensure that the sub-contracted works are carried out in accordance with the specifications & relevant drawings.

1.1.11 Compliance

All workmanship, materials & tests (where required) shall comply with the appropriate Indian or American Standards as specified or approved & be in accordance with the drawings all to the satisfaction of the Client/Engineer.

1.1.12 Supply of Materials

a. The Contractor shall supply certificates of compliance with specified Indian Standards for all materials supplied for the works. Manufacturer’s catalogues & samples of materials proposed for procurement & to be used in the works shall be submitted to the Client for approval, before procurement.

b. Materials procured without specific approval of the Client shall not be allowed to be used in the works.

c. The Contractor’s quoted rate shall include but not limited to:

i. Preparation & submission of shop drawings wherever necessary, calculation sheets, schedule of materials, & providing catalogues about, & samples of materials, & obtaining approval from the Client.

ii. Carryout of mix design, sampling and testing of construction materials, preparation and testing of trial mixes, preparation and testing of concrete test cubes, and obtaining approval from the Client.

iii. Transporting to the Site, including loading & unloading.

iv. Providing certificates of compliance with required relevant standards, as specified.

v. Storing & protection of the materials at the Site.



1.1.13 Ordering Materials

The Contractor is entirely responsible for assessing the quantities of materials to be ordered for use in the works.

1.1.14 Material Quality

The Contractor should note that the qualities of all materials used shall be scrutinized, monitored & checked by the Client. All materials used have to fulfill the requirements & specifications given in the drawings & in the relevant code of practice. If the Contractor is asked to supply certificate of origin of the supplied & used materials, he has to do so within a reasonable timeframe fixed by the Engineer.

1.1.15 Equipment & Facilities

The Contractor shall provide & operate equipment & facilities to load, offload, shift, move, transport, stack & place all types of steel parts & materials at the bridge site as well as at the Contractor’s yard.The Contractor shall also provide all lifting equipment & facilities to lift, shift, stack, load, unload & handle all type of steel parts & materials at the bridge site as well as at the Contractor’s yard.

1.1.16 Work Site Register (Site Order Book)

The Contractor shall keep a Work Site Register (Site Order Book) at the Site in which all the remarks, instructions, decisions of the Client & the essential details of the work shall be recorded. The Contractor shall keep the records of all daily information of the works in this register as required by the Client. It shall be readily available in the office for inspection.

1.1.17 Area for the Contractor

i. The Contractor shall be allocated an area for his equipment, materials & site offices in the vicinity of the bridge site. If there are only private lands in the vicinity of the bridge site, the Contractor has to arrange for the same at his own cost.

ii. The Contractor shall maintain a properly furnished office, which will include but not necessarily limited to lock up drawers for construction drawings, filing cabinets, large sized soft board panels, etc., with toilet facility in the allocated area at the site for his own use as well as for use of the Client & his representatives. These shall be provided by the Contractor at no extra cost.

1.1.18 Unit of measurement

The following units of measurement & abbreviations shall be used.

Unit Abbreviation



Millimeter mmMeter mSquare millimeter mm2

Square meter m2

Hectare haCubic metre m3

Kilogram kgTonne tonSum sumNumber no.Hour hrWeek wk (7 days)Pieces pcs

1.2 SITE INSTALLATION

1.2.1 Establishment of temporary infrastructure and facilities

As a part of the site installation, the contractor shall build and maintain all temporary infrastructures such as contractor’s office, stores, workshops, Contractor's yard, labor camp, access roadsetc. for smooth implementation of the works.

The following facilities, but not limited to, shall be installed/built and maintained by the contractor as a part of the site installation:-

1.2.1.1 Contractor’s site office

The contractor shall build and maintain a site office with sanitary facilities during the project duration. The site office shall have a minimum plan area of 30m2 and shall have at least CC flooring, bamboo mat or ekra wall and tin roof. The contractor’s site office shall have tables and chairs sufficient to conduct site meetings between the contractor and the representatives of the Client

1.2.1.2 Labor Camps

Labor camps with sufficient and maintained sanitary facilities, sufficient & safe drinking water and sufficient supply of electric power have to be made available at all times during the project duration.

The labor camps shall at least have CC flooring, bamboo mat wall and tin roof. The size and number of such camps shall be approved by the Engineer based on the labor strength requirement after contractor submits the master work plan



1.2.1.3 Waste Management

A proper waste management facility and system have to be put in place to maintain general cleanliness of the site and upkeep hygiene of the personnel and laborers working at the bridge site. The proposed facilities have to be approved by the Engineer.

1.2.1.4 Material Storage

Construction materials have to be stored well under sheds to avoid quality drops and loss.

Minimum following facilities have to be erected at the bridge site as a part of site installation for material storage:-

i. Cement store – min. plan area 40m2, CC flooring, tin wall & roof (water tight and limited air circulation) - 1 no.

ii. General store – min. plan area 25m2, CC flooring, bamboo mat/ekra wall and tin roof - 1 no.

1.2.1.5 Temporary Drainage System

The Contractor shall build a temporary drainage system at the site to drain out waste water. The layout and design of the drains have to be approved by the Engineer.

1.2.1.6 Site Water Supply and Electricity

The Contractor shall make his own connections for water and electric supply and pay for them.

The water supplied must be potable and must be free from salts, oils, acids, arsenic and other substances harmful to health. The water shall be tested to confirm its portability

If electricity is not available at the bridge site, the Contractor shall install generators of sufficient number and capacity to power all the facilities at the bridge site such as the Engineer’s Office, Contractor’s office, laboratory, labor camps, stores etc. If the Contractor intends to use electrically operated construction equipment and machinery, matching number and capacity of generators have to be installed at the bridge site.

1.2.2 Additional facilities to be provided

As a part of the site installation, the contractor shall provide/build/install following additional facilities:-

1.2.2.1 Survey Equipment

The Contractor will be required to provide survey equipment for the use of the Contractor and Engineer and his staff. The equipment and all its accessories shall be available at all times at the bridge site during the contract period and shall be maintained in good working order. For higher accuracy and better ease of use, the equipment shall be Total Station or equivalent. The contractor shall depute appropriately qualified and trained personnel to operate the survey equipment at all times during the contract period.



The survey equipment and its accessories (legs, reflectors and stands, rechargeable batteries and charger etc.) shall be from any reputable manufacturer. The range, accuracy, least count etc. of the equipment has to be approved by the Engineer.

1.2.2.2 Sign Boards

The Contractor shall provide identification sign boards and maintain them in good condition. All information on the signboards will be written in English and Dzongkha. The signboards will be positioned as directed by the Engineer.

Each sign shall show:

the name of the Project

the name of the Employer

name of the Contractor

Contract start and completion dates

Contract amount

Any other details as required by the Engineer

Project Signboards shall have steel pipe posts of diameter from 75mm to 100mm with 3mm thick steel plates. The steel pipe legs shall be embedded in the ground. The design of the signpost and the information content on it shall be approved by the Engineer.

The contractor shall install at least one sign board at the bridge site, the location of which shall be approved by the Engineer.

The Contractor shall remove the sign boards on completion of the Works or when instructed by the Engineer

1.2.3 Testing of Materials1.2.3.1 Contractor’s Site Laboratory

The Contractor shall provide and maintain a Site Laboratory in a semi-permanent building of about 25m2 plinth area with CC floor, bamboo mat wall & tin roof for the use of the Contractor and the Engineer.

The laboratory shall have furniture, testing equipment and consumable stocks necessary to carry out the tests listed below:-

1. Moisture Content

2. Particle Size Distribution

3. Standard Compaction

4. Flakiness Index

5. Fineness Modulus

6. Aggregate Crushing Value

7. Slump Test



8. Concrete Crushing Strength

The Contractor would be required to mobilize, but not limited to, the following equipment for quality assurance tests both at site and at the site laboratory as a part of site installation:

1. Moisture can

2. Weighing balance (accuracy 0.01 gm)

3. 1000 ml glass cylinder with rubber bung

4. Graduated measuring cylinder

5. Hydrometer

6. Thermometer

7. Sample tray

8. Straight edge knife

9. Scoop

10. Mixing trowel

11. Sand pouring cylinder with lid

12. Metal tray

13. Flakiness index gauge

14. Sieve set

15. Slump cone

16. Scale

17. Concrete crushing machine

18. *Concrete cube mould

19. Tamping rod

20. Hand gloves & filter papers

21. Concrete thermometers

*The Contractor shall provide a sufficient number of cube moulds to meet the testing frequency requirements for the concrete pour program for all the sites under the Contract. A reasonable number of spare moulds should also be available for any ‘ad hoc’ testing that may be required.

The laboratory shall be housed inside a proper shelter. The layout, size and location of the site laboratory have to be approved by the Engineer.

The Contractor shall maintain the laboratory, furniture, fittings and testing equipment for the duration of the Contract and replace any part or item that is irreparably damaged or lost. The Contractor shall pay all expenses in respect of water, electricity and other consumables necessary for the running of the laboratory and shall arrange for the laboratory to be regularly cleaned.



The Contractor shall not be permitted to commence permanent works requiring on-site testing till the Site laboratory is complete in all respects, unless temporary testing procedures proposed by the Contractor have been approved by the Engineer.

At the end of the Contract, all materials recovered from dismantling the laboratory, together with all furniture, fittings and testing equipment will remain the property of the Contractor.

1.2.3.2 Materials Testing by Independent Laboratories

In addition to the above mentioned tests the Contractor shall arrange for the following tests to be carried out at off-site testing facilities as and when instructed by the engineer:

1. Tests on reinforcing steel

2. Tests on cement – fineness, setting time and strength

3. Aggregate crushing value

Other tests as may be decided by the Engineer

The Contractor shall be responsible for arranging off-Site laboratory tests, and all other tests indicated as the responsibility of the Contractor in different Sections of the Specifications. These tests shall be performed by off-site standard testing laboratoriesproposed by the contractor and as approved by the Engineer. All the expenses for such tests shall be borne by the contractor. The Contractor shall be responsible for all attendance of staff from these approved testing laboratories, including if necessary the provision of transport for personnel, equipment and test specimens.

1.2.3.3 Staff for Material Testing

The Contractor shall provide qualified laboratory engineers, technicians, assistants, laborers, etc. to carry out sampling and testing of materials in accordance with Specifications Sections, 1.2.3.1. Laboratory staff shall be subject to the approval of the Engineer and be available to assist the Engineer with materials testing, as and when required.

1.2.3.4 Sampling and Testing

For Concrete Mixes 1 set of tests per 100 m3 of aggregate for shape, grading, ACV / 10% Fines should be carried out.

The Contractor shall maintain complete records of test results, which may be inspected by the Engineer at any time. All test results shall be recorded on standard forms approved by the Engineer and shall be signed by the Contractor’s engineer or technician in charge of the laboratory. Completed forms shall clearly show the locations of samples, sampling dates and testing dates. Samples shall be numbered serially at the time of sampling. A copy of all test results should be submitted to the Engineer immediately after completion of the test.

The Engineer will be informed prior to any sampling or testing carried out in the laboratory and will have the right to use the facilities and equipment to make his own tests. The Contractor shall have the right to witness any sampling or testing carried out by the Engineer. On completion of the Contract the original copies of all test results shall be handed over to the Employer, via the Engineer.



1.2.4 General Contractor’s Obligations1.2.4.1 Insurance

The contractor shall obtain all risk insurance for the work, plant, equipment, personnel and labor. The modalities for the insurance shall be as per the stipulations under Clause 14 of General Conditions of Contract (GCC).

1.2.4.2 Safety measures and penalties

The regulations and guidelines for Work Place Safety issued by Ministry of Labor and Human Resources, RGoB shall be complied with at all times. The workers and the personnel shall have safe and secure working conditions at the construction site at all times and there shall be no compromise on the work place safety. The workers shall wear safety gears – helmets, boots, belts, goggles, hand gloves, welding masks etc.as may be appropriate, at the work site at all times.

The Contractor shall issue the required protective clothing and safety equipment to all his employees and provide the first aid boxes within one month of the commencement of the Contract. He is responsible for ensuring that all his employees make appropriate use of the items and maintain them in good order. The Contractor shall replace damaged, worn-out, exhausted or out of date items as necessary.

The Contractor shall build temporary scaffold, temporary stairs, working platforms, fall-down-stoppers and such other measures to allow safe and proper execution and check of the construction works. Anybody entering the worksite shall wear safety helmets at all times. If scaffold, working platforms etc. are not possible or not required, the personnel and the workers have to wear safety belts. The quality of the safety belts has to be approved by the Engineer.

If any worker is found at the worksite without appropriate safety equipment/gear, the Contractor shall be subject to a penalty of Nu. 300 per instance. The penalty amount shall be deducted from the payments for the work due to the Contractor. The Contractor has to bear the penalty himself and shall not recover the same from the worker. The photograph of the worker at the worksite without the appropriate safety gear shall be adequate enough a proof to make the Contractor liable to pay the penalty.

1.2.4.3 Protection of the Environment

The Contractor has to allow for complying with his obligations for safety, security and protection of the environment described in the Contract Documents included in the related Sub-Clauses of the Conditions of Contract. The Contractor is not allowed to dispose or dump any kind of waste materials into the river. The contractor has to, at the end of the project, remove and clean the waterway of all the temporary constructions that it has built for the purpose of securing temporary supports or restraints for the permanent structures, installations for safety measures etc. and which do not ultimately form the part of the permanent structure.



1.2.4.4 As-Built Drawings

The Contractor shall furnish sets of as-built Drawings of the Works to the Engineer, showing the permanent works as actually constructed, within one month of completion of the Works. Included in the sets of as-built Drawings will be revisions of Tender Drawings and Drawings supplied to the Contractor during the Contract as well as revisions of drawings supplied by the Contractor during the Contract. The As-built drawings submitted by the Contractor will be subject to the approval of the Engineer.

1.2.5 Maintenance and demobilizationThe Contractor shall properly maintain all the infrastructures built at the site such as office, stores, yards, labor camps etc. till the end of the Project. At the end of the Project, the Contractor has to remove and demobilize all the temporary infrastructures that it has built and restore the bridge site to its original condition and shape. The dismantling and demobilization shall be completed within the stipulated contract duration.

1.2.6 Measurement and PaymentThe site installation shall include cost of all temporary infrastructure facilities, tools, equipment, test facilities, safety gears, insurance etc. described under Section 1.2. of this TS. The quantity, size and other specifications of various facilities mentioned here are the minimum requirements. While the minimum requirements have to be fulfilled to be eligible for payment under site installation, the contractor may actually require or provide more that what is specified here for smooth implementation of the project. If the Engineer finds the site facilities provided by the contractor as per the minimum requirement in this TS inadequate for smooth or proper implementation of the works, he will have the right to demand the contractor to install/provide addition facilities/installations for which contractor cannot claim additional payment.

By signing the contract, the Contractor confirms that all efforts and costs to fulfill the task under the site installation are included in his rates. He agrees not to ask for additional payment.

1.2.7 Pay Item

1) Site Installation (facilities, tools, plant, equipment,

insurance and so forth) Lump Sum



SECTION 22.0 EARTH WORK



2.1 CLEARING AND GRUBBING

2.1.1 General

While executing the clearing and grubbing works, the trees, shrubs, pole lines, fences, monuments, pipe lines etc. within or adjacent to the work site which are not to be disturbed shall be protected properly from damage by the contractor at his own cost and nothing extra shall be paid for this.

The contractor shall take adequate precautions against soil erosion, water pollution, etc.wherever required. Before start of work/operations, the contractor shall submit to the Engineer his work plan for approval including the procedures to be followed for disposal of waste materials, etc. and the schedules for carrying out temporary or permanent erosion control works as stipulated under the earth work.

Trunks, branches and stumps of trees shall be cleaned of limps & roots and stacked. Also boulders, stones and other usable materials shall be neatly stacked at spots as directed by the Engineer.

All branches of trees extending to the work site or above roadway shall be trimmed asdirected by the Engineer and such work shall be considered incidental to the clearing andgrubbing for which no separate payment shall be made.

Methods, tools and equipment to be adopted for the work shall be such which will not affect the property to be preserved. Only such methods, tools and equipment as approved by the Engineer shall be adopted in the work. If so desired by the Engineer, the Contractor shall demonstrate the efficacy of the type of equipment to be used before the commencement of the work.

2.1.2 Clearing jungle

The work shall consist of cutting, removing and disposing of all materials such as rank vegetation, grass, brush-wood, shrubs, stumps trees and saplings of girth up to 300 measured at a height of 1m above ground level which in the opinion of Engineer are unsuitable for incorporation in the works. Where clearance of grass is only involved, no payment shall be made under the item.

The roots of trees shall be dug at least up to 600mm from ground level or 150mm below subgrade level whichever is lower. All holes or hollows formed by digging up roots shall becarefully filled up with earth, well rammed and levelled.

2.1.2.1 Measurements

Only the area over which the jungle cutting has been done shall be measured. The length and breadth shall be measured and area calculated in square metre correct to two places of decimal.

Cutting and removing of roots of trees of girth above 300 mm at a height of 1m above ground level shall be made separately in terms of number according to the sizes.



2.1.2.2 Rates

The rate shall cover the cost of carrying out all the required operations including cost of labour, materials, equipment hired, tools and plants, and incidentals necessary to complete the work. The rate also includes removal of stumps of trees less than 300mm in girthexcavation, back filling to required density, where necessary, and handling, salvaging, pilingand disposing of the cleared materials with all lift and lead up to 50m.

2.2 Felling of Trees

While clearing jungle growth, trees 300mm and above in girth (measured at a height of onemetre above ground level) to be cut, shall be approved by the Engineer and then marked atsite. Felling trees shall include taking out roots up to 600mm below ground level or 150mmbelow sub-grade level whichever is lower.

All excavation below general ground level arising out of the removal of trees, stumps etc. shallbe filled with suitable material in 200mm layer and compacted thoroughly so that thesurfaces at these points conform to the surrounding area. The trunks and branches of treesshall be cleared of limbs and tops and cut to suitable pieces as directed by the Engineer.Wood, branches, twigs of trees and other useful material shall be the property of the Employer. The serviceable materials shall be stacked in the manner as directed by theEngineer.

All unserviceable materials shall be disposed off as per the directions of the Engineer.

2.2.1.1 Measurements

Felling of trees (girth measured at a height of one metre above ground levelor top of the stump if the height of the stump is less than 1m from the ground) shall be paidfor in terms of number according to sizes given above.

2.2.1.2 Rate

The rate shall cover the cost of carrying out all the required operations including costof labour, materials, equipment hired/owned, tools and plants, and incidentals necessary tocomplete the work. The rate also includes removal of stumps of trees greater than 300mm ingirth excavation, back filling to required density, where necessary, and handling, salvaging,piling and disposing of the cleared materials with all lift and lead up to 50m.

Where a contract does not include separate items of clearing or grubbing the same shall beconsidered incidental and the contract unit prices for the same shall be considered as including clearing and grubbing operations.

2.2.2 Pay Items

1) Clearing jungle including uprooting of rank vegetation,

grass, brushwood, saplings and trees of girth up to 300mm m2

measured at height of 1m above ground level and disposal

of rubbish within 50m lead.



2) Felling trees of Girth 300 mm and more (girth measured

at a height of 1m above ground level) including cutting of no.

trunks and branches, removal of roots and stacking of

serviceable materials and disposal of rubbish within 50m lead.

2.3 EXCAVATION AND BACKFILL FOR STRUCTURES

2.3.1 General

This work shall consist of excavation, removal and satisfactory disposal of all materials necessary for the construction in accordance with requirements of these specifications and the lines, grades and cross-sections shown in the drawings or as indicated by the Engineer.

It shall also include backfilling of the excavated foundations not occupied by the structures and compacted filling with suitable materials of the permanent structures.

Classification of materials for purpose of manual excavation shall be as follows:

Hard rock

Hard rock where blasting is prohibited for any reason and excavation has to be carried out by chiselling, wedging or any agreed method.

For excavation by machines, materials shall be classified as:-

All kinds of soil

Generally any strata, such as sand, gravel, loam, clay, mud, black cotton soil, moorum, shingle, river bed boulders, soiling of roads, paths etc. and hardcore macadam surface of any description (water bound, grouted tarmac etc.), limecon crete, mud concrete and their mixtures. This category includes both ordinary and hard soil. SPECIFICATIONS FOR BUILDING & ROAD WORKS 2009

All kinds of rocks

This includes all categories of rocks - ordinary rock, hard rock requiring/not requiring blasting, hard rock requiring chiselling. This category doesn’t include hard rock excavation/cutting in the areas where conventional blasting is prohibited and requires silent blasting operation. The rock cutting by silent blasting if required shall be measured and paid for separately.

2.3.1.1 Setting out

After the site has been cleared, the limits of excavation shall be set out true tolines, curves, slopes, grades and sections as shown on the drawings or as directed by theEngineer. The Contractor shall provide all labour, survey instruments and materials such asstrings, pegs, nails, bamboos, stones, lime, mortar, concrete, etc., required in connectionwith the setting out of works and the establishments of bench marks. The Contractor shallbe responsible for the



maintenance of the benchmarks and other marks and stakes as longas, in the opinion of the Engineer, they are required for the work.

The ground levels shall be taken at 5m to 15m intervals in uniformly sloping ground and at closer intervals where local mounds, pits or undulations are met with. The ground levels shallbe recorded in field books and plotted on plans. Plans shall be drawn to a suitable scale andNorth direction and position of benchmark shall be shown on the plans. The contractor andthe Engineer shall sign the plan before the earthwork is started. The contractor at his owncost shall supply the labour required for taking levels.

2.3.1.2 Stripping and storing topsoil

When so directed by the Engineer, the topsoil existing overthe sites of excavation shall be stripped to specify depths and stockpiled at designatedlocations for re-use in covering embankment slopes, cut slopes, and other disturbed areaswhere re-vegetation is desired. Prior to stripping the topsoil, all trees, shrubs etc. shall beremoved along with their roots, with the approval of the Engineer.

2.3.2 Excavation

All excavations shall be carried out in conformity with the directions laid herein-under and in a manner approved by the Engineer. The works shall be so done that the suitable materials available from excavation are satisfactorily utilized as decided upon beforehand.

While planning of excavations, the Contractor shall take all adequate precautions against soil erosion, water pollution etc. and take appropriate drainage measures to keep the sitesfree of water.

The excavations shall conform to the lines, grades, side slopes and levels shown on the drawings or as directed by the Engineer. The Contractor shall not excavate outside thel imits of excavation. Subject to the permitted tolerances, any excess depth/ widthe xcavated beyond the specified levels/dimensions on the drawings shall be made good atthe cost of the Contractor with the suitable material of characteristics similar to that removed and compacted.

All debris and loose materials on the slopes of cutting shall be removed. No backfilling shallbe allowed to obtain required slopes excepting that when boulders or soft materials areencountered in the cut slopes, these shall be excavated to approved depth on instructionsof the Engineer and the resulting cavities filled with suitable materials and thoroughly compacted in an approved manner.

4After excavation, the sides of the excavated areas shall be trimmed and the area contouredto minimize erosion and ponding, allow for natural drainage to take place. If trees were removed, new trees shall be planted, as directed by the Engineer. The cost of planting new trees shall be deemed to be incidental to the work.

The elevations of the bottoms of footings shown on the Drawings are approximate only and the Engineer may order in writing such changes in the dimensions or elevations of footings as may be deemed necessary to secure a satisfactory foundation.



Boulders, logs and other objectionable material encountered in excavation shall be removed. After each excavation is complete the Contractor shall notify the Engineer to that effect and no footings, bedding material or structure shall be placed until the Engineer has approved the depth of excavation and the character of the foundation material.

The foundation material shall be cleared of all loose material and cut to a firm surface, either level or stepped or serrated, as specified or shown on the Drawings or directed by the Engineer.

2.3.2.1 Methods, tools and equipment

Only such methods, tools and equipment as approved bythe Engineer shall be adopted/used in the work. If so desired by the Engineer, the Contractor shall demonstrate the efficacy of the type of equipment to be used before the commencement of the work. Methods, tools and equipment to be adopted for the work shall be such which will not affect the property to be preserved

2.3.2.2 Rocks excavation:

Excavation in ordinary rock shall be carried out by crowbars, pickaxes or pneumatic drills.

Blasting operations are generally not required in this case. If the contractor wishes to resort to blasting, he can do so with the permission of Engineer, but nothing extra will be paid to him on this account.

Excavation in hard rock shall be done by chiseling where blasting operation is prohibited or is not applicable. In trenches or drains where blasting is not otherwise prohibited, the excavation in hard rock shall be carried out by blasting in the first instance and finally by chiseling so as to obtain the correct section of the trench as per drawing. The blasting operation shall be strictly as per latest RGOB blasting manuals.

2.3.2.3 Blasting

The contractor shall obtain a licence from the competent authority for obtaining andstoring the explosives. The contractor shall procure the explosives, fuses, detonators etc. fromthe Government or as per the provision in terms and condition of the contract. The Engineeror his representative shall have the right to check the contractor's store and accounts ofexplosives. The contractor shall provide facilities for this.

All blasting work shall only be done under careful supervision of trained personnel and the contractor shall take all precautions as per rules for blasting operations.

The contractor shall be responsible for any damage arising out of accident to the workmen, public or property due to storage, transportation and use of explosive during blasting operations.

2.3.2.4 Disposal of Excavated Material

Excavated material classified as suitable by the Engineer shall generally be utilized as backfill or embankment fill. Surplus suitable material shall be stockpiled at the Site. Excavated suitable material for use as backfill shall be deposited by the Contractor in spoil



heaps at points convenient for re-handling of the material during the backfilling operation and approved by the Engineer.

Excavated material classified as unsuitable as backfill by the Engineer shall be carried to waste.

Excavated material shall be deposited in such places and in such a manner as not to cause damage to roads, services or property either within or outside the right-of-way and so as to cause no impediment to the drainage of the site or surrounding area. The location of spoil heaps shall be subject to the approval of the Engineer who may require that the reference lines and the traverse lines of any part of the structure be kept free of obstruction.

2.3.2.5 Pumping and Bailing

Pumping and bailing from the interior of any foundation enclosure shall be done in such a manner as to preclude the possibility of the movement of water through or alongside any concrete being placed. No pumping or bailing will be permitted during the placing of concrete and for a period of at least 24 hours thereafter unless it is done from a suitable pump separated from the concrete work by a watertight wall or from well points.

Excavations shall be as dry as possible prior to and during placing concrete. Placing concrete under water will only be permitted if indicated on the Drawings or approved by the Engineer.

2.3.2.6 Backfilling

All spaces excavated under these Specifications and not occupied by the permanent structure shall be backfilled. However, the finished level of the back fill shall be as per the lines and levels of the finished profile of the slope shown in the design drawings. Backfilled material shall fully comply with this Specification and adequate provision shall be made for drainage. No backfilling shall commence until permission has been given by the Engineer.

Backfilling shall be well compacted and shall be done in layers, not exceeding 200mm in each layer. Each layer shall be watered, rammed and consolidated before the succeeding one is laid.

Special care shall be taken to prevent any unduly high pressure against the structures. In placing backfill and embankment, the material shall be placed insofar as possible to approximately the same height on both sides of the structure at the same time. If conditions require backfilling appreciably higher on one side, the additional material on the higher side shall not be placed until permission is given by the Engineer that the structure has enough strength to withstand any pressure created.

2.3.3 Measurements

The volume of excavation shall be measured in cubic Meters of excavated undisturbed material.

Additional excavations for slope cutting, working space and for other purposes of construction ease and convenience shall not be paid extra. The cost for such additional excavation works is deemed to be included in the unit rates under the payable items and



quantities of the excavation works. The removal of slides, cave-ins, silting or filling shall also neither be measured nor paid for.

The soil/rock excavation for construction/widening of approach roads to the bridge however shall be measured as actual volume of excavation as per the drawings or as directed by the Engineer as per the actual requirement of the site. The contractor has to do a detail survey of the area to be excavated as per direction of the Engineer prior to and after the excavation to arrive at the actual volume of excavation. The measured volume shall be in-situ volume and no allowance shall be allowed for bulking and other forms of volume change.

However the areas around the foundations excavated by the contractor for creating working space, stabilizing excavation slope, etc. shall be backfilled to required degree of compaction and using the same backfill materials/ boulder filling as per this specification at contractor’s own cost.

2.3.4 Payment

The rates shall cover the cost for carrying out all the required operations including costof labour, materials, equipment hired/owned, tools and plants, plate load test and incidentals necessary tocomplete the work. In case of rock, the rate shall also include the cost of all operations ofblasting with explosive and accessories as mentioned above.

2.3.5 Pay Items

1) Earthwork excavation over area, depth>300mm, width>1.5m, area>10 Sq.m on plan, including the disposal of excavated earth with 50m lead

Hard rock requiring chisellingm3

2) Filling work between the gabion walls to required degree of compaction.

m3

.

.



SECTION33.0 CONCRETE & OTHER RELATED WORKS



3.1 CONCRETE FOR STRUCTURES

3.1.1 Standards

The concrete materials, production, methods, testing & admixtures shall conform to the latest revisions of the following Indian Standards or, where not covered by these standards, to the equivalent International Standards:

IS: 8112 43 grade Ordinary Portland Cement.IS: 12269 53 grade Ordinary Portland Cement. IS: 383 Coarse & fine aggregates from natural sources for aggregates.IS: 456 Code of practice for plain & reinforced concrete.IS: 457 Code of practice for general construction of plain & reinforced concrete for dams &

other massive structures. IS: 516 Method of test for strength of concrete. IS: 1199 Methods of sampling & analysis of concrete. IS: 1489 Portland Pozzolana cement. IS: 2386 Methods of test for aggregates for concrete.

IS: 2505 Concrete vibrators – immersion type – general.

IS: 2506 General requirements for screed board concrete vibrators. IS: 4082 Stacking & storage of construction materials & components at site– recommendations. IS: 7861 Code of practice for extreme weather concreting.IS: 9103 Admixtures for concrete.IS: 10262 Recommended guidelines for concrete mix design.IRC: 112 Code o Practice for Concrete Road Bridges

In cases of conflict between or among the above standards & the specifications given herein, the decision of the Client shall prevail.

3.1.2 Description

This work shall consist of the construction of all or portions of concrete structures, of the required grades and types, with or without reinforcement and with or without admixture, in accordance with these Specifications and to the lines, levels, grades and dimensions shown on the Drawings and as required by the Engineer.

The cement concrete shall consist of a mixture of cement, water and coarse and fine aggregate with or without admixture.

3.1.3 Materials

3.1.3.1 Specifications for Materials

A) Cement

Cement shall conform to the requirements of Indian Standardas mentioned in Article 3.1.1 of this specification unless other types are indicated on the Drawings or specified by the Engineer.



One of the types of the cements, specified below shall be used.

a) Ordinary Portland cement conforming to IS: 269

b) Portland blast furnace slag cement conforming to IS: 455

e) Portland pozzolana cement conforming to IS: 1489

Bagged or bulk cement which has partially set or which contains lumps of caked cement shall be rejected. The use of cement reclaimed from discarded or used bags shall not be permitted.

B) Water

Water used for mixing mortars and concrete shall be clean and reasonably free from injurious quantities of deleterious materials such as oils, acids, alkalis, salts and vegetable growth. Generally potable water shall be used. Where water can be shown to contain any sugar or an excess of acid, alkali or salt, the Engineer may refuse to permit its use. As a guide, the following concentrations may be taken to represent the maximum permissible limits of deleterious materials in water.

(a) Limits of acidity: - To neutralize 200 ml sample of water, it should not require more than 2 ml of 0.1 N caustic soda solutions.

(b) Limits of Alkalinity: - To neutralize 200 ml sample of water it should not require more than 0.1 ml of 0.1 N hydrochloric acid.

(c) Percentage of solids should not exceed: -

Organic 200 ppm (0.02%)

Inorganic 3000 ppm (0.30%)

Sulphates 500 ppm (0.05%)

Alkali chlorides 1000 ppm (0.1%)

Water found satisfactory for mixing is suitable for curing concrete. However, the water used for curing should not produce any objectionable stain or deposit on the concrete surface.

The use of river water will be subject to the approval of the Engineer. Such approvals may be withdrawn from time to time depending on the condition of the river.

C) Admixtures

Admixtures or any other additions shall not be used except with the written approval ofthe Engineer.

Admixtures, if specified or permitted, shall fully conform to the requirements of IndianStandard IS: 9103

D) Coarse Aggregate

Coarse aggregate for all types of concrete with the exception of blinding concrete shall consist of hard durable crushed or broken rock and generally conform to the requirements of Indian Standard IS:383 (or AASHTO Standard Specification M 80 or ASTM C33 / C33M – 08). Coarse aggregate shall be clean, free from dust and other deleterious material.



The amounts of deleterious substances shall not exceed the following limits:

1) Soft fragments; 2% by mass

2) Clay lumps; 0.25% by mass

3) Material Passing the 0.075 mm sieve; 0.50% by mass if clay,1.50% by mass if fractures dust

In addition, coarse aggregates shall comply with the following:

1) Thin or elongated pieces; Flakiness Index less than 30

2) The aggregate crushing value shall be less than 30% and the ten percent fines value shall be greater than 150 kN.

The grading of coarse aggregate of shall conform to Error: Reference source not foundbelow.

Table 3.1-1Grading Requirements Coarse Aggregate

In heavily reinforced structures with difficult casting conditions smaller size aggregates may be used if approved by the Engineer.

E) Fine Aggregate

Fine aggregate shall consist of natural sand and fine aggregates from different sources of supply shall not be mixed or stored in the same pile.

The amounts of deleterious substance when tested shall not exceed the following limits:

1) Friable Particles; 0.5% by mass

2) Coal and Lignite; 0.5% by mass

3) Material passing the 0.075 mm sieve; 3.0% by mass

4) Any other deleterious materials shall not cause a strength reduction of the concrete of more than 5% in relation to the strength of concrete free of the concerned deleterious material.



The grading shall normally be in accordance with Error: Reference source not found. In the event that it is not possible to obtain regular supplies of sand conforming to this grading, the Engineer may approve the adoption of analternate grading conforming to the requirements of the mix design. However, any additional cost results from changes in aggregate proportions or additional cement contents required to achievethe specified strengths, when using these alternative grading, shall be borne by the Contractor and shall not be reimbursed.

Table 3.1-2Grading Requirements for Fine Aggregate

Grading Requirements for Fine Aggregate

Sieve Size (mm) % Passing by Weight

10.0 1005.0 95-1001.2 45-800.30 10-300.15 2-10

3.1.3.2 Testing of Materials

A) Cement

Cement shall be in accordance with Indian Standard. The Contractor must provide the Engineer with manufacturer’s certificates indicating compliance.

Cement shall be sampled and tested for fineness, setting time and strength in accordance with IS:615at the Contractor’s expense. The Contractor shall notify the Engineer of delivery dates so that there will be sufficient time for sampling the cement, either at the mill or upon delivery. If this is not done, the Contractor may be required to re-handle the cement in the store for the purpose of obtaining the required samples.

Sampling shall normally be instructed by the Engineer for every batch of cement prior to this cement being incorporated in the Works.

B) Water

The water proposed by the Contractor to be used in mixing or curing concrete shall be tested by methods described in Indian Standard or AASHTO Test Method T 26 [or ASTM C1602 / C1602M – 06].

In sampling water for testing, care shall be taken that the containers are clean and that samples are representative.

When comparative tests are made with a water of known satisfactory quality, any indication of unsoundness, marked change in time of setting, or a reduction of more than 10 percent in mortar strength, shall be sufficient cause for rejection of the water under test.



The water shall be tested at a recognized laboratory approved by the Engineer. The test result shall be signed by the laboratory. The water shall be tested before commencement of work or if the source is changed or at any time required by the Engineer. All testing shall be carried out at the Contractor’s expense.

C) Admixtures

Chemical admixtures are not to be used until permitted by the Engineer. In case their use ispermitted, the type, amount and method of use of any admixtures proposed by the Contractorshall be submitted to the Engineer for approval. The minimum cement specified shall not bereduced on account of the use of the admixtures.

The contractor shall provide the following information concerning each admixture to the Engineer:

a. Normal chemical dosage and detrimental effects if any of under dosage and over dosage.

b. The chemical names of the main ingredients in the admixtures.

c. The chloride content, if any, expressed as a percentage by weight of admixture.

d. Whether or not the admixture leads to the entrainment of air when used in the manufacturer’srecommended dosage.

e. Where two or more admixtures are proposed to be used in any one mix, the manufacturer’swritten confirmation of their compatibility.

3. In reinforced concrete, the chloride content of any admixture used shall not exceed 2 percent byweight of the admixtures as determined in accordance with IS: 6925 and the total chloride andsulphate contents in concrete mix shall not exceed 1.15 and 4.0 percent respectively by weight ofcement.

The admixtures when used shall conform to IS: 9103. The suitability of all admixtures shall beverified by trial mixes.

The addition of calcium chloride to concrete containing embedded metal will not be permittedunder any circumstances.

Retarding admixtures when used shall be based on ligno-sulphonates with due consideration toclause 5.2 and 5.3 of IS: 7861

D) Aggregates

1) Selection and Approval

From the aggregate materials proposed by the Contractor, samples shall be selected according to Standard Testing Procedure and in the presence of the Engineer. The samples shall be tested at the site laboratory or at an approved testing laboratory for conformance with Section 3.1.3.1of these Specifications.

2) Quality Control



The quality control of the aggregate shall be as directed by Engineer. Grading shall normally be checked daily.

Moisture contents of fine aggregate shall be determined daily and at any time when a change in moisture content is expected.

If the Contractor proposes to change the source of aggregate, the Engineer shall be informed in advance and in no case less than 3 weeks before the new aggregate shall be used.

3.1.3.3 Composition of Concrete

A) Classes of Concrete

Concrete with cement type as specified for incorporation in the Works shall be of the classes indicated on the Drawings and shall comply withTable 3.1-3.

Table 3.1-3 Concrete classes

Concrete Class

28 days Characteristic Strength(N/mm2) (15cmx15cm15cm

Cube)

Maximum Size of Coarse Aggregate

(mm)

Minimum Cement

Content (Kg/m3)

M77 40

20

180

210

M1010 40

20

210

240

M1515 40

20

250

280

M2020 40

20

300

320

M2525 40

20

340

360

M30 3040

20

370

400

M3535 40

20

400

430



B) Proportioning

When designing the concrete mix, the Contractor shall consider the following conditions:

1) Strength

The class of the concreteis to be as shown on the Drawings. The class is the specified characteristic cube strength at 28 days. Concrete mixes shall be designed to comply with Specifications Section3.1.3.4.

2) Water/Cement Ratio

The ratio of free water to cement when using saturated surface dry aggregate shall be as low as possible and not exceed 0.50 by weight for all concrete, except for blinding concrete where it shall not exceed 0.6, unless approved by the Engineer.

For concrete in barriers, edge beams and bridge decks directly exposed to traffic or concrete in pile caps or abutments in contact with the ground, the water cement ratio shall not exceed 0.45, unless approved by the Engineer.

3) Minimum Cement Content

As indicated for the respective class in Table 3.1-3

4) Minimum Filler Content

Filler content (fine aggregate less than 0.25 mm and cement) shall not be less than as follows (except for mass concrete).

Maximum coarse aggregate size (mm) 20 40

Minimum filler content (kg/m 3 of concrete) 435 350

5) Coarse Aggregate

The maximum size of coarse aggregate will generally be stated on the Drawings; either 40 mm or 20 mm

6) Fine Aggregate

The grading and quality is to comply with the requirements of Section3.1.3.1.

7) Workability

The concrete shall be of suitable workability to obtain full compaction. Slumps measured in accordance with approved standard procedure shall not exceed 75 mm unless otherwise indicated on the Drawings or approved by the Engineer.

C) Trial Mixes

After the Contractor has received approval for the cement and aggregate to be used, he shall prepare trial mixes with concrete of designed proportions to prove and establish workability, strength, water cement/ratio, surface criteria etc. Methods of transporting fresh concrete and the compaction equipment shall be considered. The trial mixes shall be made and compacted



in the presence of the Engineer, using the same type of plant and equipment as will be used for the Works.

From each trial mix, cylinders or cubes shall be made and tested in accordance with Section3.1.3.4.

From the same mix as that from which the test specimens are made, the workability of the concrete shall be determined by the slump test. The remainder of the mix shall be cast in a wooden mould and compacted. After 24 hours the sides of the mould shall be struck and the surface examined in order to satisfy the Engineer that an acceptable surface can be obtained with the mix.

The trial mix proportions should be approved if the required strength is obtained from tests carried out in accordance with Section 3.1.3.4and the consistency and surface is to the satisfaction of the Engineer.

When a mix has been approved, no variations shall be made in the mix proportions, or in the type, size, grading zone or source, of any of the constituents without the consent of the Engineer, who may require further trial mixes to be made before any such variations are approved.

Until the results of trial mixes for a particular class have been approved by the Engineer, no concrete of the relevant class shall be placed in the Works.

When the Contractor intends to purchase factory-made precast concrete units, trial mixes may be dispensed with provided that evidence is given to satisfy the Engineer that the factory regularly produces concrete which complies with the Specifications. The evidence shall include details of mix proportions, water/cement ratios, slump tests and strengths obtained at 28 days.

3.1.3.4 Control of Concrete Quality

A) General

The Contractor shall assume the full responsibility for the quality of the concrete conforming to these Specifications and this responsibility shall not be relieved by the testing carried out and approved by the Engineer.

The Contractor shall thus at his own discretion establish additional testing procedures as necessary.

B) Control of Concrete Production

1) Materials

Materials used shall be tested in accordance with the relevant sections of this specification.

2) Plant and Equipment

Batching plants will be tested by the Contractor in a manner approved by the Engineer before any major concrete casting and at any other time if requested by the Engineer. The concreting plant and equipment shall have a capacity for at least 50m3 of concreting per day.



3) Fresh Concrete

The frequency of slump tests shall be as directed by the Engineer, with at least one test per 25 m3 of concrete.

C) Control of Strength

C.1) Sampling and Testing

The Contractor shall take samples of the concrete for testing. The number, frequency and location shall be decided by the Engineer. A minimum of 3 concrete cubes should be taken for each day’s casting, or for every 15 m3 of concrete cast in large pours. The slump of concrete samples shall be measured.

The procedures for sampling and making cubes and testing them shall be as described in IS: 1199/IS: 516 (or ASTM C873 / C873M - 04e1.)

C.2) Strength Requirement

The results of the testing shall conform to the strength requirements according to IS: 456 or to any mathematically correct statistical test for each casting section.

C.2.1) General

The characteristic strength of concrete is the 28 days strength below which not more than 5% of the test results may be expected to fall.

C.2.2) Target Mean Strength

The concrete mix should be designed to have a mean strength greater than the required characteristic strength by at least the current margin.

The current margin for each particular type of concrete mix shall be determined; it may be taken as having the smaller of the values given by (1) or (2) below.

C.2.2.1)1.64 times the standard deviation of tests on at least 100 separate batches of concrete of nominally similar proportions of similar materials and produced over a period not exceeding 12 months by the same plant under similar supervision.

C.2.2.2)1.64 times the standard deviation of tests on at least 40 separate batches of concrete of nominally similar proportions of similar materials and produced over a period exceeding 5 days but not exceeding 6 months by the same plant under similar supervision.

Where there are insufficient data to satisfy (1) or (2) above, the margin for the initial mix design should be taken as one-thirds of the characteristic strength for concrete. This margin should be used as the current margin only until sufficient data are available to satisfy (1) or (2) above. However, when the required characteristic strength approaches the maximum possible strength of concrete made with a particular aggregate, a smaller margin may be permitted by the Engineer for the initial mix design.

C.2.3) Testing Plan



Each cube shall be made from a single sample taken from randomly selected batches of concrete.

Compliance with the specified characteristic strength may be assumed if:

1) The average strength determined from any group of four consecutive test cubes exceeds the specified characteristic strength by not less than 0.5 times the current margin, and

2) Each individual test result is greater than 85% of the specified characteristic strength.

The current margin should be taken to be one-thirds (1/3) of the specified characteristic strength for concrete, unless as mentioned above a smaller margin has been established to the satisfaction of the Engineer.

If only one cube result fails to meet the second requirement then that result may be considered to represent only the particular batch of concrete from which that cube was taken provided the average strength of the group satisfies the first requirement.

If more than one cube in a group fails to meet the second requirement or if the average strength of any group of four consecutive test cubes fail to meet the first requirement then all the concrete in all the batches represented by all such cylinders shall be deemed not to comply with the strength requirements. For the purposes of this sub-Section, the batches of concrete represented by a group of four consecutive test cylinder/cubes shall include the batches from which samples were taken to make the first and the last cubes in the group of four, together with all the intervening batches.

C.2.4) Action to be taken in the event of Non-Compliance with the Testing Plan

When the average strength of four consecutive test cubes fail to meet the first requirement in (F), above, the mix proportions of subsequent batches of concrete should be modified to increase the strength.

The action to be taken in respect of the concrete which is represented by the test-cubeswhich fail to meet either of the requirements (or not by correct statistical proof can be verified to have the required strength) shall be determined by the Engineer. This may range from qualified acceptance in less severe cases, to rejection and removal in the most severe cases.

The Engineer may also require the Contractor at his own expenses to prove statistically the strength, by boring out cores and testing them according to a program approved by the Engineer. The age of the concrete and degree of hardening at the time of the new testing shall be considered. The equivalent cylinder/cube strength shall comply the minimum characteristic strength or as decided by the Engineer.

D) Control of Hardening

If the Contractor wants to remove forms and scaffolding earlier than specified herein, extra test specimens shall be cast by the Contractor in accordance with the instruction of the Engineer. These specimens shall be tested the day before removal of the form. On the basis of the test results the Engineer shall take the final decision on the time for the removal of forms.



3.1.4 Construction Methods

3.1.4.1 General

The Contractor shall in due time and as soon as possible present and discuss his construction methods and work program with the Engineer and shall obtain his approval before commencement of any work.

The Contractor shall maintain an adequate number of trained and experienced supervisors and foremen at the Site to supervise and control the work.

All construction, other than concrete, shall conform to the requirements prescribed in other Sections of the Specifications, for the particular items of work comprising the complete structure.

3.1.4.2 Care and Storage of Concrete Materials

A) Storage of Cement

All cement shall be stored in suitable weatherproof buildings or silos which will protect the cement from dampness. These buildings or silos shall be placed in locations approved by the Engineer. Provisions for storage shall be ample, and the shipments of cement as received shall be separately stored in such manner as to provide easy access for the identification and inspection of each shipment. Storage buildings shall have acapacity for the storage of a sufficient quantity of cement to allow sampling at least 14 days before the cement is to be used. Cement shall meet the test requirements at any time and any cement stored for an elongated time shall be checked and tested before use regardless of whether it has previously been tested.

B) Storage of Aggregates

Aggregates shall be so stored as to prevent the inclusion of foreign material. Aggregates shall not be placed upon the finished roadbed. Aggregates of different sizes and kinds shall be placed in different stockpiles. Stockpiles of blended coarse aggregates shall be built up in successive horizontal layers not more than 1 Meter thick. Each layer shall be completed before the next is started. Should segregation occur, the aggregates shall be recombined to conform to the grading requirement.

Washed aggregates and aggregates produced or manipulated by methods which involve the use of water shall be allowed to drain at least 12 hours before use.

3.1.4.3 Preparations before Casting

Before any major casting, the Contractor shall prepare a complete “casting program” describing staff and labor, consumption of materials, plant, tools and equipment, reserves of materials, standby plant and equipment, proposed means of handling and placing the concrete, quality controls etc.

No concrete shall be mixed and placed until the Contractor’s casting program has been approved in writing by the Engineer.



Equipment and tools necessary for handling materials and performing the work, and satisfactory to the Engineer as to design, capacity, and mechanical condition, shall be at the site of the work before casting is started.

If any equipment is not maintained in full working order, or if the equipment as used by the Contractor proves inadequate to obtain the result prescribed, such equipment shall be repaired or other suitable equipment substituted or added at the discretion of the Engineer.

3.1.4.4 Measuring Materials

All material in the mix shall be proportioned by weight or volume, subject to the approval of the Engineer.

When volume batching is proposed by the Contractor, the exact proportions must be converted from trial mix weights to volumes, from bulk densities determined in the laboratory. Written approval from the Engineer is required.

3.1.4.5 Mixing Concrete

A) General

All concrete shall be mixed in batch mixers, either at the site of construction, at a central plant, or in transit. Each mixer shall have attached to it in a prominent place, a manufacturer’s plate showing the capacity of the drum in terms of mixed concrete and the speed of rotation of the mixing drum.

B) Mixers at Local Site of Construction

Mixers at local sites shall be approved drum-type capable of combining the aggregate, cement, and water into a thoroughly mixed and uniform mass within the specified mixingperiod and of discharging the mixture without segregation. The mixer shall be equipped with a suitable charging hopper, water storage and a water measuring device, accurate within 1%. Controls shall be so arranged that the water can be applied only while the mixer is being charged. Suitable equipment for discharging the concrete shall be provided. The mixer shall be cleaned at suitable intervals. The pickup and throw-over blades in the drum shall be replaced when they have lost 10% of their depth.

The mixer shall be operated at a drum speed of between 15 and 20 revolutions per minute. The batched materials shall be so charged into the drum that a portion of the water shall enter in advance of the cement and aggregates and the water shall continue to flow into the drum for a minimum time of 5 seconds after all the cement and aggregates are in the drum. Mixing time shall be measured from the time all materials except water are in the drum and shall, in the case of mixers having a capacity of 1 cubic Meter or less, not be less than 50 seconds nor more than 70 seconds. In the case of dual drum mixers, the mixing time shall not include transfer time. The contents of an individual mixer drum shall be removed before a succeeding batch is emptied therein. Any concrete mixed less than the specified minimum time shall be discarded and disposed of by the Contractor at his own expense.



The volume of concrete mixed per batch shall not exceed the mixer’s nominal capacity in cubic feet or cubic Meters as shown on the manufacturer’s guaranteed capacity standard rating plate on the mixer; except that an overload up to 20% of the mixers nominal capacity may be permitted provided concrete test data for strength, segregation and uniform consistency are satisfactory, and provided no spillage of concrete takes place.

Re-tempering concrete by adding water or by other means shall not be permitted. Concrete which is not of the required consistency at the time of placement shall not be used and shall be discarded and disposed of by the Contractor at his own expense.

C) Central Plant Mixers

These mixers shall be of approved drum type capable of combining the aggregate, cement and water into a thoroughly mixed and uniform mass within the specified mixing period and of discharging the mixture without segregation. Central plant mixers shall be equipped with an acceptable timing device that will not permit the batch to be discharged until the specified mixing time has elapsed. The water system for a central mixer shall be either a calibrated measuring tank or a meter and shall not necessarily be an integral part of the mixer.

The mixers shall be cleaned at suitable intervals. They shall be examined daily for changes in interior condition. The pick up and throw-over blades in the drum shall be replaced when they have lost 10% of their depth.

In addition to the requirements for mixers at local sites detailed above, central plant mixers which have a capacity of between 2 and 5 cubic Meters, or greater than 5 cubic Meters, should have a minimum mixing time of 90 and 120 seconds respectively, provided tests indicate that the concrete produced is equivalent in strength and uniformity to that attained as stated in the preceding paragraphs.

Mixed concrete shall be transported from the central mixing plant to the site of work in agitator trucks or, upon written permission of the Engineer, in non-agitator trucks. Delivery of concrete shall be so regulated that placing is at a continuous rate unless delayed by the placing operations. The intervals between deliveries of batches shall not be so great as to allow the concrete in place to harden partially, and in no case shall such an interval exceed 30 minutes.

D) Agitator Trucks

Unless otherwise permitted in writing by the Engineer, agitator trucks shall have watertight revolving drums suitably mounted and shall be capable of transporting and discharging the concrete without segregation. The agitating speed of the drum shall not be less than two or more than six revolutions per minute. The volume of mixed concrete permitted in the drum shall not exceed the manufacturer’s rating nor exceed 80% the gross volume of the drum.

Upon approval by the Engineer, open-top, revolving-blade truck mixers may be used in lieu of agitating trucks for transportation of central plant mixed concrete.



Gross volume of agitator bodies expressed in cubic feet or cubic Meters shall be supplied by the mixer manufacturer. The interval between introduction of water into the mixer drum and final discharge of the concrete from the agitator shall not exceed 45 minutes. During this interval the mix shall be agitated continuously.

E) Non-Agitator Trucks

Bodies of non-agitating equipment shall be smooth, water-tight metal containers equipped with gates that will permit control of the discharge of the concrete. Covers shall be provided when needed for protection against the weather.

The non-agitating equipment shall permit delivery of the concrete to the site of the work in a thoroughly mixed and uniform mass with a satisfactory degree of discharge.

Uniformity shall be satisfactory if samples from the one-quarter and three quarter points of the load do not differ by more than 30 mm in slump. Discharge of concrete shall be completed within 30 minutes after the introduction of the mixing water to the cement and aggregate.

F) Truck or Transit Mixers

These shall be equipped with electrically actuated counters by which the number of revolutions of the drum or blades may readily be verified and the counters shall be actuated at the commencement of mixing operations at designated mixing speeds. The mixer when loaded shall not be filled to more than 60% of the drum gross volume. The mixer shall be capable of combining the ingredients of the concrete into a thoroughly mixed and uniform mass and of discharging the concrete with a satisfactory degree of uniformity.

Except when intended for use exclusively as agitators, truck mixers shall be provided with a water measuring device to measure accurately the quantity of water for each batch. The delivered amount of water shall be within plus or minus 1% of the indicated amount.

Truck mixers may be used for complete mixing at the batch plant and as truck agitators for delivery of concrete to job sites, or they may be used for complete mixing of the concrete at the job site. They shall either be a closed watertight revolving drum or an open top revolving blade or paddle type.

The amount of mixing shall be designated in number of revolutions of the mixer drum. When a truck mixer is used for complete mixing, each batch of concrete shall be mixed for between 70 and 100 revolutions of the drum or blades at the rate of rotation designated by the manufacturer of the equipment as the “mixing speed”. Such designation shall appear on a metal plate attached to the mixer. If the batch is at least 0.5 cubic Meters less than guaranteed capacity, the number of revolutions at mixingspeed may be reduced to not less than 50. Mixing in excess of 100 revolutions shall be at the agitating speed. All materials, including the mixing water, shall be in the mixer drum before actuating the revolution counter which will indicate the number of revolutions of the drum or blades.



When wash water (flush water) is used as a portion of the mixing water for the succeeding batch, it shall be accurately measured and taken into account in determining the amount of additional mixing water required. When wash water is carried on the truck mixer, it shall be carried in a compartment separate from the one used for carrying or measuring the mixing water. The Engineer will specify the amount of wash or flush water, when permitted, any may specify a “dry” drum if wash water is used without measurement or without supervision.

When a truck is used for complete mixing at the batch plant, mixing operations shall begin within 30 minutes after the cement has been added to the aggregate. After mixing, the truck mixer shall be used as an agitator, when transporting concrete, at the speed designated by the manufacturer of the equipment as agitating speed. Concrete discharge shall be completed within 45 minutes after the addition of the cement to the aggregates. Each batch of concrete delivered at the job site shall be accompanied by a time slip issued at the batching plant, bearing the time of departure there from. When the truck mixer is used for the complete mixing of the concrete at the job site, the mixing operation shall begin within 30 minutes after the cement has been added to the aggregates.

The rate of discharge of the plastic concrete from the mixer drum shall be controlled by the speed of rotation of the drum in the discharge direction with the discharge gate fully open.

3.1.4.6 Handling and Placing Concrete

The temperature of concrete at the time of placing shall not be below 50C or above 35°C.

In preparation for the placing of concrete all sawdust, chips and other construction debris and extraneous matter shall be removed from the interior of forms. Struts, stays and braces, serving temporarily to hold the forms in correct shape and alignment, pending the placing of concrete at their locations, shall be removed when the concrete placing has reached an elevation rendering their service unnecessary. These temporary members shall be entirely removed from the forms and not buried in the concrete.

Concrete must reach its final position in the forms within 20 minutes of the completion of mixing, or as directed by the Engineer.

Concrete shall be placed so as to avoid segregation of the materials and the displacement of the reinforcement. The use of long troughs, chutes and pipes for conveying concrete from the mixer to the forms shall be permitted only on written authorization of the Engineer. In case an inferior quality of concrete is produced by the use of such conveyors, the Engineer may order discontinuance of their use and the institution of a satisfactory method of placing.

Open troughs and chutes shall be of metal or metal lined. Where long steep slopes are required, the chutes shall be equipped with baffles or be in short lengths that reverse the direction of movement.

All chutes, troughs and pipes shall be kept clean and free from coatings of hardened concrete by thoroughly flushing with water after each run. Water used for flushing shall be discharged clear of the structure.



When placing operations would involve dropping the concrete more than 1 .5 m, it shall be deposited through sheet metal or other approved pipes. As far as practicable, the pipes shall be kept full of concrete during placing and their lower ends shall be kept buried in the newly placed concrete. After initial set of the concrete, the forms shall not be jarred and no strain shall be placed on the ends of reinforcement bars which project.

Concrete, during and immediately after depositing, shall be thoroughly compacted. The compaction shall be done by mechanical vibration subject to the following provisions:

1) The vibration shall be internal unless special authorization of other methods is given by the Engineer or as provided herein.

2) Vibrators shall be of a type and design approved by the Engineer. They shall be capable of transmitting vibration to the concrete at frequencies of not less than 4,500 impulses per minute.

3) The intensity of vibration shall be such as to visibly affect a mass of concrete of 20 mm slump over a radius of at least 450 mm.

4) The Contractor shall provide a sufficient number of vibrators to properly compact each batch immediately after they are placed in the forms.

5) Vibrators shall be manipulated to thoroughly work the concrete around the reinforcement and embedded fixtures, and into the corners and angles of the forms.

Vibration shall be applied at the point of deposit and in the area of freshly deposited concrete. The vibrators shall be inserted and withdrawn from the concrete slowly. The vibration shall be of sufficient duration and intensity to thoroughly compact the concrete, but shall not be continued so as to cause segregation. Vibration shall not be continued at any one point to the extent that localized areas of grout are formed.

Application of vibrators shall be at points uniformly spaced and not further apart than twice the radius over which the vibration is visibly effective.

6) Vibration shall not be applied directly or through the reinforcement to sections or layers of concrete which have hardened to the degree that the concrete ceases to be plastic under vibration. It shall not be used to make concrete flow in the forms over distances so great as to cause segregation, and vibrators shall not be used to transport concrete in the forms.

7) Vibration shall be supplemented by such spading as is necessary to ensure smooth surfaces and dense concrete along form surfaces and in corners and locations impossible to reach with the vibrators.

8) The provisions of this Section shall also apply to precast piling, concrete cribbing and other precast members except that, if approved by the Engineer, the manufacturer’s methods of vibration may be used.



Concrete shall be placed in horizontal layers not more than 600 mm thick except as hereinafter provided. When less than a complete layer is placed in one operation, it shall be terminated in a vertical bulkhead. Each layer shall be placed and compacted before the preceding batch has taken initial set to prevent injury to the green concrete and avoid surfaces of separation between the batches. Each layer shall be compacted so as to avoid the formation of a construction joint.

3.1.4.7 Removal of Scaffolding and Formwork

Forms and scaffolding shall not be removed without the approval of the Engineer. The Engineer’s approval shall not relieve the Contractor of his Contract responsibilities. Any kentledge blocks and bracing shall be removed at the same time as the forms and in no case shall any portion of the wood forms be left in the concrete.

Forms used on exposed vertical faces shall remain in place for periods which shall be determined by the Engineer and normally not less than 3 days.

Supporting scaffolding and forms under slabs, beams and girders shall normally remain in place until the full required strength of the concrete has been obtained. If a shorter period is requested, this may be permitted by the Engineer.

All structures shall be fully stripped before adjacent structures are cast.

3.1.4.8 Repair of Concrete

As soon as the form has been stripped, the Contractor shall advise the Engineer who shall inspect the concrete before any improvement of the surface takes place.

All wire or metal devices used for securing the formwork which project from or appear on the surface of the finished concrete shall be removed or cut back to at least a depth equal to the required reinforcement cover. All holes and pockets so formed shall be filled with cement mortar mixed in the same proportions as the fine aggregate to cement of the concrete mix used for that particular section of the structure, after the surface to be patched has been thoroughly cleaned and wetted to receive the patch.

Excessive honeycombing shall be sufficient to cause rejection of portions of the structure containing this honeycombing. The Contractor, on receipt of written orders from the Engineer, shall remove and rebuild such portions of the structure at his own expense.

Smaller honeycombing and other defects can be repaired if permitted by the Engineer. Structural, maintenance and aesthetical points of view shall be taken into consideration before such approval, if any, may be given. The method of repair shall be approved by the Engineer and an extension of period for a certain part of the performance bond may be required.

3.1.4.9 Depositing Concrete under Water

Concrete shall not be deposited in water except with the approval of the Engineer and under his immediate supervision; and in this case the method of placing shall be as defined in this Section.



Concrete placed under water shall be carefully placed in a compact mass, in its final position, by means of a tremie tube and shall not be disturbed after being deposited. Special care must be exercised to maintain still water at the point of deposit. Concrete shall not be placed in running water. The method of depositing concrete shall be so regulated as to produce approximately horizontal surfaces.

Concrete seals shall be placed in one continuous operation. When a tremie tube or pipe is used, it shall consist of a tube or pipe not less than 150 mm in diameter. All joints in the tube shall be watertight. The means of supporting the tremie tube shall be such as to permit free movement of the discharge end over the entire top of the concrete and to permit its being lowered rapidly when necessary to choke off or retard the flow. The tremie tube shall be filled by a method that prevents washing of the concrete. The discharge end shall be completely submerged in concrete at all times and the tremie tube shall be kept full. Concrete slump shall not be less than 150 mm.

Dewatering shall proceed only when the concrete seal is considered strong enough to withstand any pressure to be exerted upon it. This time shall be decided by the Engineer.

3.1.4.9.1 Cleaning Up

Upon completion of a structure and before final acceptance, the Contractor shall remove all forms and scaffolding etc. down to 0.5 Meters below the finished ground line. Excavated, or useless materials, rubbish etc. shall be removed from the Site and the Site shall be left in a neat and tidy condition satisfactory to the Engineer.

3.1.5 Measurement

Concrete shall be measured by the number of cubic Meters of Class indicated on the Drawings complete in place and accepted by the Engineer. In computing quantities, the dimensions used shall be those shown on the Drawings.

3.1.6 Payment

The concrete of grades shown on the Drawings and measured as provided in Section 3.1.5shall be paid for at the Contract unit prices per cubic Meter. The Contractor’s rates shall include materials, mixing, transporting, placing and compacting the concrete. The rates shall also include all trial mixes (as specified in Section3.1.3.3), all conformance tests, all concrete finishings, the supply, placing and building in of weep pipesor pipe sleeves, forming construction joints, forming holes or pockets not exceeding 0.15 m3 each.

Payment for precast units shall include all concrete, formwork, finishing, transport and erection and where applicable any bolts, bedding or other devices necessary to fix them in their permanent position.

3.1.7 Pay Items

1) Providing and laying leveling concrete in Plain Cement

Concrete of grade M10 under RCC hume pipe m3



2) Providing & laying of concrete of grade M10 as filling

Concrete between the RCC hume pipes m3

3.2 Formwork and Scaffolding

Details, plans and structural calculations for scaffolding shall be submitted by the Contractor to the Engineer for approval, but in no case shall the Engineer’s approval relieve the Contractor of his contract responsibilities. All scaffolding shall be designed and constructed by the Contractor to provide the necessary rigidity and to support dead and live loads without deflection or deformation. The Engineer may require the Contractor to employ screw jacks or hardwood wedges to take up any settlement in scaffolding and formwork, either before or during the placing of concrete.

Tests may be required by the Engineer of materials proposed by the Contractor for scaffolding. Test loadings of the completed scaffolding may also be required for the determination of flexibility and strength. All expenses associated with testing shall be borne by the Contractor.

Scaffolding which cannot be founded on a satisfactory footing shall be supported on piles, which shall be spaced, driven and removed in a manner approved by the Engineer. When the Contractor wishes to support scaffolding on existing structures, he shall submit his proposals in due time to the Engineer, in writing, including loads from the scaffolding. The Engineer will consider the proposals and respond in writing.

Scaffolding shall be set to give the finished structure a camber, if indicated on the Drawings or specified by the Engineer.

Scaffolding shall remain in place for periods which shall be determined by the Engineer.

The formwork shall be properly designed for the self-weight, weight of reinforcement, weight of fresh concrete, various live loads imposed during the construction process (such as workmen and equipment). Dumping of concrete, movement of construction equipment and action of the wind may produce lateral forces which must be resisted by the form work to prevent lateral failure for which suitable horizontal as well as diagonal bracings shall be provided. The permissible stresses in bending, buckling load of props, permissible deflection of shuttering should not be exceeded.

In case the height of centering exceeds 3.50 Meters, the props may be provided in multi-stages.

Before the concreting is started, the props and wedges shall be thoroughly checked to see that these are intact, and take suitable action in case these are loose. While the concreting is in progress, at least one carpenter shall be readily available at the site. The carpenter shall keep a constant watch on the props and take immediate remedial measures, as soon as any of these get loosened. Care shall be taken that props and wedges do not get loose for a minimum period specified in Error: Reference source not found.



3.2.1 Formwork

Formwork shall include all temporary or permanent moulds for forming the concrete. Formwork shall be of wood, metal or other approved materials and shall be built mortar tight and rigid enough to maintain the concrete in position during placing, compacting, setting and hardening.

Formwork for exposed surfaces (“wrought form”) shall be made of dressed lumber of uniform thickness with or without a form liner of an approved type or shall be of metal sufficiently rigid in itself with no surface blemishes that will impair the quality of the concrete surface finish. No rusty or bent metal forms shall be used. Exposed concrete arises shall be provide with formed chamfers, as indicated on the Drawings or instructed by the Engineer.

Rough lumber may be used for surfaces that will not be exposed in the finished structure (“rough form”).

All lumber shall be sound, free from warps and twists, sap, shakes, large or loose knots, wavy edge or other defects affecting the strength or appearance of the finished structure.

All forms shall be set and maintained true to the line designated until the concrete is sufficiently hardened. Forms shall remain in place for periods, which shall be determined by the Engineer. When forms appear to be unsatisfactory in any way, either before or during the placing of concrete, the Engineer may order the work stopped until the defects are corrected.

If requested, the Contractor shall submit to the Engineer working drawings of the forms and also, if requested, calculations to verify the rigidity and strength of the forms.

The shape, strength, rigidity, water tightness and surface smoothness of reused formwork shall be maintained at all times. Any warped or bulged lumber must be re-sized before being reused. Formwork that is unsatisfactory in any respect shall not be reused.

Metal ties or anchorages within the form shall be so constructed as to permit their removal to a depth of at least 50 mm from the face without injury to the concrete. All fittings for metal ties shall be of such design that, upon their removal, the cavities which are left will be of the smallest possible size. The cavities shall be filled with cement mortar and the surface left sound, smooth, even and uniform in color.

Formwork shall be so constructed that easy cleaning out of any extraneous material inside the formwork can be achieved without disturbing formwork already checked and approved by the Engineer.

Formwork shall be treated with approved non-staining oil or saturated with water, to facilitate formwork removal. The Engineer may require trials to be carried out before approval is given for the use of a particular type of oil, to ascertain that the oil proposed by the Contractor does not discolor or injure the finished concrete face in any way.

Before placing any concrete, all shavings, loose binding wires, soil, rubbish and all foreign matter shall be removed from the formwork and the formwork shall be carefully and



thoroughly washed with water. If not indicated otherwise, the following tolerances of the finished concrete structures shall apply:

Foundations: horizontally ±30 mm; vertically ±20 mm

Piers: Horizontally±20 mm, vertically~ 10mm, inclination 1:400

Dimensions of other structural members: + 10 mm, -5 mm

3.2.1.1 Surface Treatment for Shuttering

The surfaces of timber shuttering that would come in contact with concrete shall be well wetted and coated with soap solution, raw linseed oil or form oil of approved manufacture, to prevent adhesion of concrete to form work. Use of polythene sheets shall not be permitted. Soap solution, for the purpose shall be prepared by dissolving yellow soap in water to get the consistency of paint. Inside surfaces of forms shall be thoroughly cleaned before application of any of the materials mentioned above. Release agents shall be applied strictly in accordance with the manufacturers’ instructions and shall not be allowed to come in contact with any reinforcement. Re-use of the shuttering shall be permitted only after the inside surface has been thoroughly cleaned in the manner described above.

Contractor shall give the Engineer due notice before placing any concrete in the forms to permit him to inspect and accept the form work as to its strength alignment and general fitness, but such inspection shall not relieve the contractor of his responsibility for safety of workman, machinery, materials and for results obtained.

3.2.1.2 Camber

Cambers both along and across the bridge shall be provided as per the lines and levels shown in the design drawings or as directed by the Engineer. The scaffold and the formwork shall be so assembled as to provide for such camber. For cantilevers, the camber at free end shall be 1/50th of the projected length or as directed by the Engineer.

3.2.2 Approval of Scaffolding and Formwork

If plans and calculations of scaffolding and formwork are sought by the Engineer, no construction of such scaffolding and formwork shall take place before approval by the Engineer, in writing. Such approval shall not relieve the Contractor of his responsibilities under the Contract for the adequacy of scaffolding and formwork.

The Engineer shall have reasonable time for his examination of the Contractor’s plans and calculations, especially if scaffolding is introducing temporary loading on new structures. The Contractor shall not be allowed extensions of Contract time due to awaiting such approval.

The Engineer shall inspect all formwork and scaffolding and no concrete shall be placed until the Engineer’s approval has been given. Such approval shall not relieve the Contractor of any of his responsibilities under the Contract for the successful completion of the structure..



3.2.3 Removal of Form Work

No formwork or any part thereof shall be removed without prior approval of the Engineer. The formwork shall be so removed as not to cause any damage to concrete due to shock or vibration

The whole of the formwork should be planned and a definite scheme of operation worked out. In no circumstances should forms be struck until the concrete reaches strength of at least twice the stress to which the concrete may be subjected at the time of striking. Where possible the formwork should be left longer as it would assist curing. Forms should be eased carefully in order to prevent the load being suddenly transferred to concrete. The period that shall elapse after the concrete has been laid, before easing and removal of centering and shuttering is undertaken shall be as given in Error: Reference source not foundbelow:

3.2.4 Measurements

The formwork shall be paid for separately. Measurement shall be taken of the area of shuttering in contact with the concrete surface.

Dimensions of formwork shall be measured correct to 10mm. The measurements shall be taken separately under each of the items mentioned in the Pay Item.

3.2.5 Payment

The rate of formwork includes the cost of planning & design of a safe scaffold system, material, erection, centering & propping, shuttering and formwork and other materials, tools and plant, labor required for all the operations described in this section including properly supporting the members as required until the concrete is cured, set and hardened as required. No separate payment shall be made for items such as form release agent, connections, ties, provisions for openings and other items required for the completion of the work unless specified otherwise.

3.2.6 Pay Items

1) Centering and shuttering including

all scaffolds and propping works:

a) Sides of concrete works below RCC hume pipes m2

b) For sides of concrete works between RCC hume pipes m2

3.3 RCC hume pipes

3.3.1.1 Scope

This work shall consist of providing & laying of RCC Hume pipes .



3.3.1.2 Material

All HDPE pipes shall comply with Indian Standard IS 458:2003 Standard Specification for Precast Concrete Pipes

3.3.1.3 PlacementThe pipes shall be placed in true position, lines and levels as shown in the drawing with necessary b and held in place firmly..

3.3.2 Measurement

The drainage pipes with matching collars shall be measured in running meter for the specified diameter of pipes as shown in the drawings.

3.3.3 Payment

RCC Hume pipes as shown in the drawings and defined in the BoQ, will be paid for at the Contract unit price.

The price and payment shall constitute full compensation for furnishing all materials as indicated in the Drawings including delivery, placement, finishing and for all labor, equipment, tools and incidentals necessary to complete the work.

3.3.4 Pay items:

1) Providing and laying of NP2 RCC hume pipe with matching collars

as detailed in the drawings and defined in the Bill of Quantities M

3.4 Stone Work

3.4.1 Scope

This Section covers furnishing of materials and construction of different types of stone masonry works in accordance with the Drawing and this Specification or as directed by the Engineer. These works will be required for retaining structures, drains and channel lining, slope and drainage protection works or other works as directed by the Engineer.

Activities involved will include supply of stones, dressed bond stone, cement, sand, water, equipment, tools, preparation of mortar, placing and joining stones dry/with mortar, curing, collection and testing of specimens, etc.

3.4.2 MaterialsAll requirements in respect of stones and cement sand mortar described herein shall be applicable inall Clauses of this Section, if otherwise not specified.

3.4.3 Stone

The stones to be used shall be durable and angular in shape. If boulders are used they shall be broken into angular pieces. The stones shall be sound, hard, and free from iron bands, spots, sand holes, flaws, shakes, cracks or other defects. The stone shall not absorb water more than 5 per cent. Stones for coursed or uncoursed stone rubble masonry shall have broken face on three sides. Stones for dressed rubble masonry shall have dressed face on all sides. Except



otherwise described in the contract, the length of any stone shall not exceed three times its height. The breadth of the stone on the bed shall not be less than 150 mm nor greater than 3/4th thickness of the wall. At least 80% of the stones used in masonry, except those used for chinking as chips or spalls of stones shall have individual volumes of more than 0.01 m3 .The chips or spalls used including voids in the dry stone masonry shall not be more than 20% of the stone masonry by volume. In case of mortared masonry the total volume of mortar and spalls taken together shall not be more than 30% of the mortared masonry. Representative samples of the stones intended for use in the works shall be submitted to the Engineer for prior approval. Further representative samples shall be submitted for approval whenever there is a change in the type or strength of the rock that the Contractor intends to use in masonry work.

3.4.4 Cement Mortar

Mortar shall comply with IS 2250–1981; Code of Practice for preparation and use of masonry mortar. The mortar used in work shall have the strength not less than 5 N/mm2 or 7.5 N/mm2

at 28 days as specified. For example class MM 5 means cement sand mortar in the ratio to attain compressive strength not less than 5 N/mm2 at 28 days. The grade of cement sand mortar shall be as specified in the Bill of Quantities.

Sand shall comply with IS 2116. Cement shall be ordinary Portland cement as per IS 8112 or IS 12269.

Water shall be clean and free from detrimental concentration of acids, alkalis, salts, and other organic or chemical substances. If instructed by the Engineer the Contractor shall prove the suitability of the water by tests carried out by an approved laboratory. Such tests shall comply with the requirements of IS: 3029-1964.

The mixing shall be done in a mechanical mixer unless hand-mixing is permitted by the Engineer. If hand-mixing is allowed, the operation shall be carried out on a clear watertight platform. In the required proportion cement and sand shall be first mixed dry to obtain uniform colour. Then required quantity of water shall be added and the mortar shall be mixed to produce workable consistency. The mortar shall be mixed for at least three minutes after addition of water in the case of mechanical mixing. In the case of hand mixing, the mortal shall be hoed back and forth for about 10 minutes after addition of water in order to obtain uniform consistency.

Only that quantity of mortar shall be mixed at a time which can be used completely before it becomes unworkable. Any mortar that has become unworkable due to loss of water before elapsing the initial setting time of cement shall be rewet to make it workable and shall be used in the works. On no account mortar shall be used after elapsing the initial setting time of cement.

3.4.5 Construction

The method of construction described herein shall hold well in all Clauses of this Section, wherever applicable.



3.4.6 General

Construction shall be carried out in accordance with I.S. 1597-1992, Code of Practice for construction of stone masonry, Part 1 Rubble stone masonry or Part 2 Ashlar Masonry as appropriate. All stratified stone possessing bedding planes shall be laid with its natural bed as nearly as possible at right angles to the direction of load. In the case of arch rings, the natural bed shall be radial. Facework groins shall be built to a height not exceeding one metre in advance of the main body of the work and adjacent walling stepped down on either side. Masonry face work between the groins shall then be built to a height not exceeding 500 mm above the backing which shall then be brought up level with the completed facework. At no time shall the backing be built up higher than the facework.

Except for dry rubble walling, all joints (gaps) shall be sufficiently thick to prevent stone to stone contact and the gaps shall be completely filled with mortar. Stones shall be clean and sufficiently wetted before laying to prevent absorption of water from mortar.

Placing loose mortar on the course and pouring water upon it to fill the gaps in stones shall not be allowed. Mortar shall be fluid, mixed thoroughly and then poured in the joints. No dry or hollow space shall be left anywhere in the masonry and each stone shall have all its faces completely covered with mortar of the thickness as specified for joints.

The bed which is to receive the stone shall be cleaned, wetted and covered with a layer of fresh mortar. All stones shall be laid full in mortar both in bed and vertical joints and settled carefully in place with a wooden mallet immediately after placement and solidly embedded in mortar before it has set. Clean and wet chips and spalls shall be wedged into the mortar joints and bed whenever necessary to avoid thick joints or bed of mortar. When the foundation masonry is laid directly on rock, the bedding face of the stones of the first course shall be dressed to fit into rock snugly when pressed down in the mortar bedding over the rock. For masonry works over rock, a levelling course of M15/40 or M15/20 concrete 100mm thickness shall be laid over rock and then stone masonry work shall be laid without foundation concrete block.

In case, any stone already set in mortar is disturbed or the joints broken, it shall be taken out without disturbing the adjoining stones and joints. Dry mortar and stones shall be thoroughly cleaned from the joints and the stones shall be reset in fresh mortar. Sliding one stone on top of another which is freshly laid shall not be allowed.

Shaping and dressing of stone shall be done before it is laid in the work. Dressing and hammering of the laid stones which will loosen the masonry shall not be allowed.

Building up face wall tied with occasional through stones and filling up the middle with stones spalls and chips or dry packing shall not be allowed. Vertical joints shall be staggered. Distance between the nearer vertical joints of upper layer and lower layer in coursed rubble masonry shall not be less than half the height of the course.

Masonry in a structure between two expansion joints shall be carried up nearly at one uniform level throughout but when breaks are unavoidable the masonry shall be raked in



sufficiently long steps to facilitate jointing of old and new work. The stepping of raking shall not be more than 45 degrees with the horizontal.

Masonry shall not be laid when the air temperature in the shade is less than 3°C. Newly laid masonry shall be protected from the harmful effects of weather.

The holes left in the masonry work for supporting scaffolding shall be filled and finished with M150 grade concrete.

The masonry work in cement mortar shall be kept constantly moist for a minimum period of 7 days, unless otherwise specified.

3.4.7 Concrete Capping

Where masonry structures are constructed to receive a concrete capping the joints to the upper surface of the masonry shall be raked out to a depth of 10 mm prior to placing of the concrete to the capping. The concrete for capping shall be carried out as per the design drawing or as directed by Engineer.

3.4.8 Pointing

Where external faces of the mortared masonry work will be backfilled or otherwise permanently covered up, the mortared joint shall be finished flush to the faces of the adjacent stonework.

Where mortared masonry faces will remain exposed, the mortar joints shall be pointed to a consistent style as shown on the Drawing. Pointing shall be carried out using mortar MM7.5 cement mortar or as shown on the Drawing or as shown on the Drawing or as directed by the Engineer. The mortar shall be filled and pressed into the raked out joints before giving the required finish. The pointing, if not otherwise mentioned, shall be ruled type for which it shall, while masonry work is still green, be ruled along the centre with half round tools of such width as may be specified by the engineer. The excess mortar shall, then, be taken off from the edges of the lines and shall not be unnecessarily plastered over the exposed stone works. The thickness of the joints shall not be less than 3mm for Ashlar masonry.

However, the maximum thickness of joints in different works shall be as follows:

Random Rubble : 20mm

Coursed Rubble : 15mm

Ashlar Masonry : 5mm

3.4.9 Weep holes

Weep holes shall be provided in solid plain concrete/reinforced concrete, brick/stone masonry, abutment, wing wall or other structures as shown on the Drawing or as directed by the Engineer. Weep holes shall be provided with 100mm dia polythene pipe for structures in plain/reinforced concrete or brick masonry. In case of stone masonry, weep holes shall be 100 mm wide, 100 mm high or circular with 100 mm diameter. Weep holes shall extend through the full width of concrete/masonry with a slope of 1 vertical 20 horizontal towards the



draining face. The spacing of weep holes shall generally be 1 m in either direction or as shown on the drawing with the lowest at about 150 mm above the low water level or ground level whichever is higher or as directed by the Engineer. Surfaces of the weep holes shall be smooth and it shall be ensured that the water is properly drained from the backfill.

3.4.10 Ashlar

All stones shall be dressed to accurate planes on the beds and joints and they shall be fair and neatly or fine tooled on the face unless otherwise described in the contract.

3.4.11 Block-in-Course

Beds and joints shall be squared and dressed for a distance of at least 220 mm from the exposed face. Bond stones shall form at least one sixth of the area of the exposed face and shall extend at least 900 mm into the wall or for the full thickness of the wall whichever is minimum. Unless described in the contract as tooled or drafted, the exposed face of all stones shall be blocked and left rough. Arises shall be dressed square at all beds and joints.

3.4.12 Square Rubble- Coursed or Broken Courses

All stones shall be truly squared and dressed for a distance at least 120 mm from the face of the wall. Bond stones shall be provided at the rate of at least one to every 0.5 m2 of exposed face and shall measure not less than 150 mm x 150 mm on the face and not less than 450 mm in length or the full thickness of the wall, whichever is the less. Vertical joints in any layer shall be broken in the next layer and the horizontal lapping of the stones shall not be less than 100 mm.

3.4.13 Random Rubble - Coursed or Uncoursed

All stones shall be carefully set with bond stones running right through the thickness of walls up to 600 mm thickness and in case of walls above 600 mm thickness a set of two or more bond stones overlapping each other by minimum 150 mm shall be provided in a line from face to back. At least one bond stone or a set of bond stones shall be provided for every 0.5 m2 of the wall surface. If the bond stone of sufficient length is not available then plain cement concrete (M150 grade concrete) block of cross-section not less than 200x150 mm shall be provided.

In case of highly absorbent types of stones (porous lime stone and sand stones etc) the bond stone shall extend about two third into the wall. The bond stones in such cases may give rise to damp penetrations therefore, for all thickness of such walls, a set of two or more bond stones overlapping-each other by at least 150 mm shall be provided.

For random rubble masonry, the quoins shall be of selected stones neatly dressed with the hammer chisel to form the required angle, and laid header and stretcher alternately.

In case of coursed rubble masonry, the face stones shall be dressed on all beds and joints so as to give them approximately rectangular block shape. The bed joint shall be dressed for at least 80 mm back from the face and side joints for at least 40 mm such that no portion of the dressed surface is more than 10 mm from a straight edge placed on it. The remaining portion of the stone shall not project beyond the surface of bed and side joints. The bushing on the



face shall not project more than 40 mm on exposed face and 10 mm on a face to be plastered. The face stones shall be laid alternate headers and stretchers without pinning on the face. Bond stones shall be provided as specified above except that the spacing of a bond stone or set of bond stones shall be about 1.5 m or as directed by the Engineer. The quoins shall be of same height as the course. These shall be minimum 380 mm long and laid alternate header and stretcher.

3.4.14 Dry Random Rubble

Dry random rubble masonry shall be constructed generally to the requirements of coursed random rubble masonry as specified in Clause 8.7 but with the omission of mortar. All stones shall be carefully shaped to obtain as close a fit as possible at all beds and joints, any interstices between the stones being filled with selected stone spalls. No round stones shall be used in dry stone masonry work. The stones in courses shall be laid perpendicular to the batter face. Bond stones shall be provided at the rate of at least 10 percent of volume of dry stone masonry structure. Bond stones shall measure not less than 150 mm x 150 mm and not less than 450 mm in length or full thickness of wall, whichever is less. The exposed tops or capping of dry rubble structures shall be formed as shown on the Drawing or as directed by the Engineer.

3.4.15 Composite Random Rubble

Materials for composite random rubble shall comply with Clause 1302 and construction with Clause 1303. Mortar masonry shall be coursed and comply with Clause 1307 and the dry stone insets with Clause 1308. The dry stone insets shall be constructed when the level of the surrounding mortared masonry surround has reached the top of the dry stone inset.

3.4.16 Stone Pitching

3.4.16.1General

Stone pitching work shall be required for lining of drains and channels.

3.4.16.2Material

The stones to be used shall be durable and angular in shape. If boulders are used they shall be broken into angular pieces. The stones shall be sound, hard, and free from iron bands, spots, sand holes, flaws, shakes, cracks or other defects. The stone shall not absorb water more than 5 per cent. Stones for pitching shall not be less than 150 mm in minimum dimension. Rounded stones shall not be used in stone pitching. The mortar shall comply with Sub-Clause 8.2.1.

3.4.16.3Mock-Up

Prior to commencement of any stone pitching work the Contractor shall construct a stone pitching panel of approximately 2000 mm x 1000 mm as a trial. The trial if accepted by the Engineer shall be the sample for actual work.



3.4.16.4Construction

Stone pitching shall be done on surface prepared to specified requirements. Stones shall be laid in mortar with their longitudinal axis across to the direction of flow. Thickness of mortar in bed shall be 25 to 35 mm. They shall be well set into the surface. Thickness of pitching will be as shown on Drawings or as directed by the Engineer. Spaces between stones shall be filled with spalls. Finished surface shall present an even, tight and neat appearance with no stones varying by more than 20 mm from specified grades and lines. Joints between the stones shall be completely filled with MM 7.5 mortar. Finished surface shall present an even, tight and neat appearance with no stones varying by more than 20 mm from specified grades and lines.

3.4.16.5Stone Soling

Stone soling are required in the construction of foundation beds for various structures. Stones shall comply with Sub-Clause 8.1.2 of this specification. Stone soling shall be done on foundation surface prepared as specified. They shall be well rammed into the surface. Spaces between stones shall be filled with spalls or smaller stones securely rammed into voids. The completed work shall present an even, neat and tight surface.

3.4.16.6Test & Standard of Acceptance

Before laying any mortar, the Contractor shall make three sets of mortar test cubes from each source of sand to demonstrate the compliance of the mix to the specified strength. Each set shall comprise two cubes, one to be tested at 7 days and the other to be tested at 28 days. During construction, the Contractor shall make and test mortar cubes at the rate of three cubes for every 10 m3 of masonry to assess the strength subject to a minimum of 3 cubes samples for a days work. Testing of cubes shall be in accordance with IS 2250. The stones shall be tested for the water absorption as per IS1124 and it shall not be more than 5 percent. Sand shall be tested as directed by the Engineer. At least 3 set of tests for stone and sand shall be conducted for every source.

3.4.16.7Measurement

Stone work shall be measured in cubic metres. No separate measurement shall be carried out for pointing.

Weep holes shall not be measured separately. No deduction in the volume of structures shall be made for weep holes.

3.4.17 `Payment

The stone masonry shall be paid at the respective contract unit prices which shall be the full and the final compensation to the Contractor to complete the work in accordance with these Specifications.

Pay Item

1) Providing & laying of Random Rubble Masonry in CM 1:4

incl. top PCC 1:2:4.



The item shall also include providing of hard bond [email protected]/c m

2) Providing and laying dry stone wall in G.I wire mesh 4mm (8 SWG) - double knotted mesh ….100mm, including supplying and weaving of mesh complete as defined in BoQ

a) Height of 4m-------------------------------m

b) Height of 5m-------------------------------m

SECTION 44.0 ROAD WORK


mailto:[email protected]/c


4.1 EXCAVATION FOR FOUNDATION, DITCHES, PAVEMENT, SLOPES, LANDSLIDES

4.1.1 Excavation for Ditch, Clearing of Existing Drains and Channels

Ditch excavation shall consist of excavation for drains, channels, or any other type as designated on Drawings or as directed by the Engineer. The work shall be performed in the proper sequence with other construction. The location of all ditches shall be established on the ground before starting construction of adjacent works. Suitable excavated material shall be placed in fills or stockpiles while unsuitable or surplus material shall be placed in spoil areas or as directed by the Engineer. Intercepting ditches shall be constructed prior to the starting of adjacent excavation operations. The excavation operations shall be carried out as required to secure a finish true to line, elevation and cross section, as designated.

Ditches constructed in the works shall be maintained to the required cross-section and shall be kept free from debris or obstructions until completion of the contract. As necessary, sufficient openings shall be provided through spoil banks to permit drainage from adjacent lands. No extra payment shall be made for ditches constructed in the works.

Existing drains and channels where shown on the Drawings or as directed by the Engineer, shall be cleared by removing vegetation growths and debris deposits. The sides shall be trimmed throughout and the bottoms uniformly graded and the ditches kept clean and trimmed and maintained for the period of the Works. Unsuitable material removed from existing drains, channels shall be disposed off in spoil areas designated by the Engineer.



4.1.1.1 Excavation (Scarification) for Pavement

During the subgrade preparation, if unsuitable materials are encountered, it shall be excavated and disposed off in designated location and the site shall be replaced with selected/suitable materials as capping layer, the density and moisture content of which is the same as the other part of the subgrade.

Where shown on the Drawings or as directed by the Engineer the existing pavement surfacing or pavement layers in carriageway and shoulders shall be scarified, transported and stockpiled at designated area for reuse or disposed to spoil. The surface after scarification shall be prepared to meet the requirements of Section 5.5 of the Technical Specifications. It will be broken, if needed, mixed to achieve required grading of base, subbase including adding extra base, subbase materials as required, watered and laid to required profiles and compacted in its final position as directed by the Engineer.

4.1.1.2 Excavation for Slopes and Removal of Landslides

Where shown on the Drawings or as directed by the Engineer the excavation shall be carried out for slopes in widening of road or curves, removal of unstable slopes/landslide, trimming of slopes, etc. The earthwork for removal of landslides shall be other than those encountered in routine maintenance of road. Suitable excavated material shall be placed in fills or stockpiles while unsuitable or surplus material shall be placed in spoil areas or as directed by the Engineer.

4.1.2 REFILLING OF FOUNDATION PITS AND TRENCHES, REMOVAL OF SUPPORTS AND FILLING TO STRUCTURES

Refilling of foundation pits and trenches shall consist of pervious backfill and/or common backfill as shown on the Drawing or as directed by the Engineer.

4.1.3 Materials

4.1.3.1 Pervious/Graded Backfill

Filter layer behind the structures shall consist of boulder (size below 200 mm) filling or unless otherwise specified in the contract, it shall consist of gravel, crushed gravel, crushed rock, natural sands, manufactured sands or combinations thereof. It shall conform to the grading limits set out in Table. 5.1.1

Table 5.1-4Grading Limits of Pervious Backfill

Sieve Size (mm) Percentage Passing by Weight

Class 1, Fine Grade Class 2, Medium Grade Class 3, Coarse Grade

40

20

10

4.75

-

-

100

90-100

-

90-100

40-100

25-40

95-100

50-100

15-55

0-25



2.36

1.18

0.60

0.300

0.150

0.075

80-100

50-95

30-75

10-30

1-10

0-3

18-33

-

5-15

0-7

-

0-3

0-5

-

-

-

-

0-3

D15 (filter)

Piping ratio ---------------- <5

D85 (soil)

D15 (filter)

Permeability ratio ---------------- >5

D15 (soil)

D50 (filter)

Mean ratio ---------------- <25

D50 (soil)

Where D15 and D50 (filter) are used to designate the size of sieve passing 15 percent and 50 percent respectively size of filter material (i.e. the size of the sieve that allows 15 percent and 50 percent respectively by weight of the filter material to pass through it).

4.1.3.2 Common Backfill

Common backfill materials other than pervious backfill shall be suitable material as defined in Sub-clause 2.3.1 or as directed by the Engineer.

4.1.4 Method of Filling

Backfilling material shall not be permitted under water unless specifically described in the contract or approved by the Engineer. It shall be placed and compacted in layers in compliance with the requirements of Clause 5.6.1. Any support structures for the excavation shall be withdrawn as the filling proceeds unless described in the contract or ordered by the Engineer to be left in. The backfill shall be placed in by such methods which shall avoid loading the structure in any manner which may affect its stability or overload its underlying foundation material or substructure. The backfill in front of abutments and wing walls shall be placed first to avoid the possibility of forward movement. Precautions shall be taken to prevent any wedge action against upright surfaces, and the slopes bounding the excavation shall be stepped as directed by the Engineer before backfill is placed. The backfill material around box culverts, piers and curtain walls shall be placed simultaneously on both sides of the structure.



4.1.5 FORMING OF EMBANKMENT AND OTHER AREAS OF FILL

(1) The work shall consist of the construction of embankment, filling on other areas and backfill not specified elsewhere by providing materials as specified or approved by the Engineer, placing, compacting and shaping to lines, levels, grades and cross sections as shown on the Drawing or as directed by the Engineer. The maximum size of the coarse material in the mixture shall not exceed 75mm for general earthfill.

(2) The limits of embankment shall be built sufficiently wider than the design dimension to facilitate in achieving required compaction nearby outerfaces of the embankment. The surplus material shall be trimmed to the specified side slopes and width of the embankment.

(3) Where necessary, the original ground shall be scarified, mixed with water, leveled and then compacted so as to achieve the density mentioned in Clause 5.6.1. Where the height of embankment, as measured from formation level to the original ground level, is less than 200 mm, the embankment foundation shall be compacted in accordance with the requirements of Clause 5.6.1 such that the required compaction is achieved within the upper 300 mm below formation level. Where necessary, embankment foundations shall be excavated/furrowed and brought under optimum moisture content and re-compacted in layers of 150mm each in order to achieve the required level of compaction.

(4) Embankments shall be built up evenly over the entire width and shall be maintained at all times with a sufficient camber to enable surface water to drain rapidly from them. Damage to compacted layers by constructional or other traffic shall be made good by the Contractor.

(5) The natural moisture content and the optimum moisture content of the material to be placed in the embankment shall be checked before start of placing material. If these parameters are found to be out of the specified limits, the same shall be made good. Where water is required to be added in such construction, it shall be sprinkled uniformly and thoroughly mixed in soil by blading or harrowing until uniform moisture content as specified is obtained.

Moisture content, checked in accordance with IS 2720 (Part 2), at the time of compaction shall be between 90% and 105% of the Optimum Moisture Content as determined in accordance with IS 2720 (Part 8).

If the material delivered for fill/backfill is too wet, it shall be dried by aeration and exposure to sun, till the moisture content is acceptable for compaction. Should circumstances arise, where owing to wet weather, the moisture content cannot be reduced by the above procedure, compaction work shall be suspended.

If the material deposited as fill subsequently reaches a condition such that it cannot be compacted in accordance with the requirements of the specifications. The Contractor shall:

Make good by removing the material off the embankment and placing suitable material; or

Make good by tipping it elsewhere until it is in a suitable physical condition for re-use; or



Make good the material by mechanical or chemical means to improve its properties acceptable to the Engineer.

(6) Where fill is required to be constructed across water logged or soft clayey ground that displays excessive movement under normal constructional equipment, it may be necessary to construct a capping layer in accordance with Clause 4.8.7.

(7) Rock used in rockfill embankments shall be deposited in horizontal layers not exceeding 450 mm each extending upto the full width of the embankment.

Material shall be spread, leveled and compacted in accordance with Clause 5.6.1. Each layer shall consist of reasonably graded rock and all surface voids shall be filled with broken fragments before the next layer is placed. The top surface and side slopes of embankments so formed shall be thoroughly blinded with approved well graded material to seal the surface.

(8) Isolated boulders each within the range of 0.05 cubic meters in size may be incorporated in embankments, not of rock fill, at the discretion of the Engineer provided that the specified compaction requirements are met and it shall not be placed less than 1 m below formation level of carriageways or shoulders.

(9) While filling embankments up to or over culverts or pipe drains, and where required in the contract, up to bridges, the Contractor shall bring the embankments up equally on both sides. In rock fill embankments the rock shall be carefully packed for such distance from the structure as described in the contract.

Where provision of filter membrane is specified behind structures, the same shall be laid in layers simultaneously with the laying of fill material.

(10) If the Contractor wishes to continue to use the surface of embankments including shallow filling for constructional traffic before trimming to formation level, he shall bring up and maintain the area between the extremities of the carriageways including (if any) central reserve and hard shoulders to a level not less than 150 mm above formation level whereupon constructional traffic shall be allowed to use the surface and shall be made good by the Contractor at his own expense. When it is necessary to complete the formation level and this has been done, the movement and use of construction equipment thereon shall be in accordance with Clause 5.4.3.

4.1.6 COMPACTION OF EMBANKMENTS AND OTHER AREAS OF FILL/BACKFILL

(a) The Contractor shall obtain the Engineer's approval of all fill layers before covering with subsequent layers.

(b) All fill shall be compacted to the depth and degree of compaction as specified in Table 5.1.6or as shown on the Drawing. This requirement applies whether the specified zone is in fill or in existing ground, except for any part which may fall within rock or rockfill. Formation level in this context shall mean top of subgrade.

Table 5.1-5Depth and Degree of Compaction



Location Depth below Formation Level (mm)

Minimum Compaction (% MDD Heavy Compaction)

RoadwayEmbankment 0-300 95

Roadway Cut 0-300 95

Backfill for soil reinforced walls with gabion facia

0-300 95

All other roadway fill and backfill not separately specified

- 93

(c) Compaction shall be undertaken to the requirements of Table 5.1-3 by approved compaction equipment.

Table 5.1-6 Compaction Requirements

Type of Compaction Equipment

Category

Cohesive SoilWell Graded granular and

Dry cohesive soilsUniformly Graded

materials

Maximum depth of

Compaction Layer

(mm)

Minimum No. of

Passes

Maximum depth of Compaction

Layer

(mm)

Minimum No. of

Passes

Maximum depth of

Compaction Layer

(mm)

Minimum No. of

Passes

Smooth Wheeled Roller Load per mm. width

or roll

2.14 - 2.67 kg. 130 8 130 10 Unsuitable

2.68 - 5.35 kg. 130 6 130 8 Unsuitable

More than 5.35 kg. 130 4 150 8 Unsuitable

Grid Roller Load per mm. width of roll

2.65 - 5.35 kg. 150 10 Unsuitable 150 10

5.36 - 8.00 kg. 150 8 130 12 Unsuitable

More than 8.00 kg. 150 4 150 12 Unsuitable




Category



materials

Maximum depth of

Compaction Layer

(mm)

Minimum No. of

Passes


Layer

(mm)

Minimum No. of

Passes

Maximum depth of

Compaction Layer

(mm)

Minimum No. of

Passes

Pneumatic Tyre RollerWheel Load

1000 – 1500 kg.

1500 – 2000 kg. 130

150

6

5

Unsuitable

Unsuitable

Unsuitable

Unsuitable

2000 – 2500 kg. 180 4 130 12 Unsuitable

2500 – 4000 kg. 230 4 130 10 Unsuitable

4000 – 6000 kg. 305 4 130 10 Unsuitable

6000 – 8000 kg. 355 4 150 8 Unsuitable

8000 – 12000 kg. 405 4 150 8 Unsuitable

More than 12000 kg. 455 4 180 6 Unsuitable

Vibratory Roller Static Load per mm. widthof Vibratory roll

0.27 - 0.44 kg. Unsuitable 75 16 150 16

0.45 - 0.71 kg. Unsuitable 75 12 150 12

0.72 - 1.25 kg. 100 12 130 12 150 6

0.26 - 1.78 kg. 130 8 150 8 200 10

1.79 - 2.32 kg. 150 4 150 4 230 12

2.33 - 2.86 kg. 180 4 180 4 255 10

2.87 - 3.56 kg. 200 4 200 4 280 8

3.57 - 4.28 kg. 230 4 230 4 305 8

4.28 - 5.00 kg. 225 4 225 4 305 6

Vibrating Plate Compactor

Static Pressure under

base plate




Category



materials

Maximum depth of

Compaction Layer

(mm)

Minimum No. of

Passes


Layer

(mm)

Minimum No. of

Passes

Maximum depth of

Compaction Layer

(mm)

Minimum No. of

Passes

0.088 - 0.105 kg/sq.cm Unsuitable Unsuitable 75 6

0.106 - 0.123 kg/sq.cm Unsuitable 75 10 100 6

0.124 - 0.141 kg/sq.cm Unsuitable 75 6 150 6

0.142 - 0.176 kg/sq.cm 100 6 130 6 150 4

0.177 - 0.211 kg/sq.cm 150 6 150 5 200 4

More than 0.211 kg/sq.cm

200 6 200 5 255 4

Vibro-tamper Weight

50 - 63 kg. 100 3 100 3 150 3

64 - 75 kg. 130 3 130 3 200 3

More than 75 kg. 200 3 150 3 230 3

Power Rammer Weight

100 kg. - 500 kg. 150 4 150 6 Unsuitable

More than 500 kg. 280 8 280 12 Unsuitable

(d) Each layer of rock used to fill in embankments shall be spread and leveled in accordance with Sub-clause 5.1.5 and systematically compacted.

(e) Layers of material other than rockfill shall not exceed 150 mm compacted depth unless and until the Contractor can demonstrate to the satisfaction of the Engineer that he can successfully compact layers of a greater thickness.



(f) Each layer shall be constructed in lengths suitable to the compaction and working methods used. Materials of each layer shall be thoroughly mixed with water as necessary to facilitate its compaction to the specified density.

(g) In cut areas, the subgrade shall be processed as necessary and compacted to the depth and compaction requirements as given in Table 6.1 and Table 6.2. In the event that the Contractor is unable to achieve the minimum compaction requirements below formation level he shall excavate and recompact in layers as necessary.

Where it may be impracticable to use conventional rollers, the compaction shall be carried out by appropriate mechanical means such as small vibratory rollers, power rammers or plate compactor. Care shall be taken to ensure that the compaction equipment does not hit or come too close to any structural member so as to cause any damage to it.

4.1.7 COMPACTION TRIALS

(1) Before commencing filling embankment and from time to time as may be considered necessary by the Engineer, the Contractor shall carry out compaction trials in the presence of the Engineer on each of the main types of soil and rockfill to be used and compacted in the Works. The Contractor shall carry out all necessary laboratory and field testing as required by the Engineer and shall submit the results of all tests to the Engineer. The trial procedure shall include the compaction of trial areas selected by the Engineer. The surface of each area shall first be well compacted to the satisfaction of the Engineer. Each type of material being used shall be compacted in equal layers at uniform but differing moisture contents to a predetermined number of passes using the Contractor's proposed compaction equipment.

(2) Following completion of the compaction trials, the Contractor shall submit to the Engineer, for his approval, his proposals for the compaction of each type of material to be encountered in the Works and its specified degree of compaction. The Contractor's proposals shall include reference to the types of equipment, the operating weights and tyre pressure, the methods of adjusting the moisture content, the number of passes and the loose depth of each layer.

(3) If, in the opinion of the Engineer, the results of the compaction trials indicate that the Contractor's proposed plant and methods shall achieve the densities as specified, the Engineer shall approve the same. Otherwise the Contractor shall submit, in writing, proposals for modifying the plant and/or methods and shall, if the Engineer so requires, compact further trial areas in accordance with these modified proposals until the Engineer approves of Contractor's proposals.

(4) When compaction of earthworks is in progress, the Contractor shall adhere to the compaction procedures approved by the Engineer.

(5) Notwithstanding the Engineer's approval of any of the Contractor's plant or methods, the Contractor shall at all times be solely responsible for executing the earthworks in accordance with the Specifications and the Drawing.



4.1.8 BENCHING

(1) Where embankments are to be constructed on hillslopes or slopes with more than or equal to 1 vertical to 4 horizontal slopes, benches with vertical and horizontal faces shall be cut into the existing slope (including rock) and the embankment shall be built up in successive layers. Where the cross slope is less than 1 vertical to 4 horizontal slope (other than rock) shall be loosened by scarifying to a depth of not less than 100 mm measured perpendicular to the slope, to ensure a good bond between the embankment and the embankment foundation. Material which has been loosened shall be covered with the first layer and compacted to the specified density simultaneously with the first layer of embankment material placed.

(2) Where existing embankments are to be widened or included in a new embankment and slopes are not more than 1 vertical to 4 horizontal, the slope of the existing embankment shall be scarified to a depth of not less than 100 mm to ensure bond. Where the slope is less than 1 vertical to 4 horizontal, continuous horizontal benches, each at least 300 mm wide, shall be cut in existing slopes and the widened embankment shall be built up in successive layers of thickness of 150 mm to the level of old road.

Where the width of the widened portions is insufficient to permit the use of heavy rollers, compaction to the specified density shall be carried out with the help of small vibratory roller/plate compactor/rammer or other approved methods.

4.1.9 FINISHING OF SLOPES

The slopes of cuttings shall be trimmed to neat line and to a standard that is attainable with proper care and workmanship in the type of material concerned. All loose rocks, stones and nests of loose material shall be removed especially in solid rock cuts which must be completely free of such material. The final surface batters must not be absolutely smooth, but shall have a slightly rough surface that would be suitable for subsequent grassing or for the natural vegetation to be established on the surface.

Fill slopes shall be finished to neat lines with all loose rocks and non-compacted material removed. The degree of finish required shall depend on the nature of the material used for the fill slopes but shall be as smooth as in consistent with the material involved and good workmanship. No boulders in excess of 150 mm in size will be permitted and isolated large boulder in otherwise smaller size material shall not be allowed to project out of the surface. In the case of rockfill soft material shall be worked into the interstices between the rock on the surface of the slope.

Except in solid rock the tops and bottoms of all slopes, including the slopes of drainage ditches, shall be rounded as indicated on the Drawings or as directed by the Engineer. Slopes at the junctions of cuts and fills shall be adjusted and warped to flow into one another, or into the natural ground surfaces, without any noticeable break.



Cut and fill slopes shall be finished to a uniform appearance without any noticeable break readily discernible from the road. The degree of finish required for all fill slopes and for cut slopes flatter than 1 in 4 shall be that obtainable by motor grader.

The slopes of cuts and fills which are designated for grassing shall, after finishing, be prepared for grass planting and /or top soil for grass planting.

All trimming of side slopes of cuttings shall be completed before any work on the subbase is commenced inside such cuttings.

4.1.10 EARTHWORKS TO BE KEPT FREE OF WATER

By providing temporary water course, ditches, drains, pumping or other means the Contractor shall arrange for the rapid dispersal of water from the areas of earthworks. Where practicable the water shall be discharged into the permanent outlet for the drainage system. Adequate means for trapping silt shall be provided on temporary systems while discharging into permanent drainage systems.

4.1.11 WATERCOURSES

Excavations carried out in the diversion, enlargement, deepening or straightening of watercourses shall include the operations of any necessary trimming of slopes, grading of beds, disposal of excavated materials and pumping, tampering works and materials necessary for dealing with the flow of water.

4.1.12 FILLING EXISTING WATERCOURSES

Where watercourses have to be diverted from the sites of embankments or other works, the original channels shall be cleared of all vegetative growths and soft deposits and filled in with suitable materials deposited and compacted as specified in Clauses 5.1.5 and 5.6.1.

4.1.13 PROCESS CONTROL

(1) Throughout the works the Contractor shall perform tests to determine the suitability and compaction characteristics of soils to be used in roadway. The compaction test shall be conducted in accordance with IS 2720 Part 8 in every 1500 cum of fill material and every change in material type. The moisture content test shall be conducted in accordance with IS 2720 Part 2 in every 250 cum of material.

(2) In addition to the foregoing tests, the Contractor shall carry out field density tests on the compacted fill materials in accordance with IS 2720 Part 28/29. At least one set of density determination consisting of three tests per 500 sqm (or any lesser area) shall be carried out in each layer, including original ground surface on which embankment is to be constructed. If the result of any test shows that the minimum specified density has not been achieved, further compaction shall be executed to the area concerned and the layer re-tested. Unless the test results are satisfactory, the addition of another layer shall not be allowed.

(3) The Contractor shall carry out tests for determination of moisture content at frequent intervals on all materials during the course of compaction as per Sub-clause 5.1.5 to ensure that the requirements of Clause 5.6.1 are met with.



4.1.14 MEASUREMENT

The quantities of the various classes of earthwork to be measured for payment under the contractshallbe limited to the lines, grades, slopes and dimensions shown on the Drawing or as determined by the Engineer.

(1) All roadway excavation including road formationshall be measured in running meters.

(2) Foundation excavation, filling and backfilling compacted in place shall be measured in cubic metres.

No separate measurement for payment shall be made for excavation made on borrows, quarries, temporary works or in places outside the scope of permanent works specified in the contract.

No measurement shall be made for any excavation other than the limited excavation described above. Excavation over increased width or length, cutting of slopes, shoring, shuttering and planking shall be deemed as convenience for the Contractor in executing the work and shall not be measured and paid for. Backfill to be measured shall be limited to this void only with due consideration of the nature of the structure.

No separate measurement shall be made for any quantities of finishing of slopes and preparatory work for formation of embankment and other areas of fill.

(3) Useof explosive materials, leveling, watering and compaction of original ground, construction of coffer dams, pumping out water and other ancillary and incidental works necessary to complete the item as per this Specification shall not be measured for payment. They are deemed to have been included in the measurement of the concerned item.

4.1.15 PAYMENT

(1) Various classes of earthworks i.e. roadway excavation shall be paid in running meters.Roadway filling, backfilling, and others measured as described above shall be paid at contract unit rate of the respective item.

(2) Foundation excavation for structures, measured as described above, shall be paid for at the contract unit rate for all classes of excavation. The contract unit rate for foundation excavation shall be the full and the final compensation to the Contractor as per the Technical Specifications. No payment shall be made for the disposal of the excavated materials irrespective of all leads and lifts, preparation of foundation base, cofferdams, cribs, sheeting, shoring and bracing, foundation sealing, dewatering including pumping, removal of logs and stumps, cleaning and grubbing, diversion of flow/channel, if required and all incidentals works necessary to complete the item in accordance with this Specification.

(3) Payment for scarifying, processing, laying, profiling and compacting existing pavement, and preparation of surface for laying of pavement layers shall be made at the contract unit rate, which shall be the full and the final compensation to the Contractor as per TS. No separate payment shall be made to the Contractor for any extra base, subbase material



required to be added to scarified subbase material to prepare it to comply the requirements of the specifications; reworking; placing and compactingfor the final position.

4.2 PROCESS CONTROL TESTING & TOLERANCESHORIZONTAL ALIGNMENTS, SURFACE LEVELS AND SURFACE REGULARITY OF PAVEMENT COURSES

(1) Construction Control Testing/Process Control Testing

Unless otherwise directed, values given in these Specifications are minimum values for the properties of materials and the workmanship. They shall be considered satisfactory, if all results of the tests, taken at the frequencies specified, are at least equal to the values given in the relevant Section of the Technical Specifications.

(2) Tolerances

(a) Horizontal Alignments

Horizontal alignments shall be determined from the centreline of the pavement surface as shown or calculated from the Drawing. The centreline of the pavement surface as constructed, and all other parallel alignments, shall be correct within a tolerance of 13 mm therefrom.

(b) Thickness of Pavement Layers

The average thickness of any pavement layer measured at five consecutive points at every 20m in any Section shall not be less than the thickness specified nor more than 120% of the thickness specified or ordered by the Engineer. The thickness of the pavement layer measured at any point shall have tolerance of + 25 % and - 2 % of the thickness specified.

(c) Surface Levels of Pavement Layers and Formation

The level measured at any point on the surface of a pavement layer to the formation level shall not deviate from the corresponding level calculated from the Drawing by more than the tolerances shown in Table 5.2.

For checking compliance with Table 5.2 measurements of surface levels shall be taken at points to be selected by the Engineer at 12.5m centres longitudinally and at 2m centres transversely. At junctions, the grid point spacing shall be determined by the Engineer.

(d) Surface Regularity

The surface regularity of pavement layers and the formation shall be tested at points decided by the Engineer with a rigid, steel straight-edge of 3 m length placed parallel to or at right angles to the centreline of the road. The maximum allowable deviation of the surface below the straight-edge shall not deviate from that shown on the Drawing by more than the tolerances shown in Table 5.2.



In addition the longitudinal slope or transverse cross fall shall not deviate from that shown on the Drawing by more than the tolerances shown on Table 7.1. If tolerances given in Table 7.1 for level and straight edge are not in agreement, the tolerances given for straight edge shall prevail.

Table 5.2-7Tolerances for Level and Surface Regularity

Layer

Level

mm

Straight edge

mm

Slope or Crossfall %

DBM/Bituminous Wearing Course 10 6* 0.25

Bituminous Binder Course 10 6 0.25

Base 10 6 0.25

Subbase 15 10 0.50

Gravel Wearing Course 15 15 0.50

Formation (subgrade) +0

-25

20 0.50

* In case of asphalt concrete surface it shall be 4mm.

(e) Shoulders

Shoulders shall be constructed to the same requirements of thickness, level and surface regularity as for the adjacent pavement layers.

(f) Cuttings and Embankment Slopes

In the final trimmed slope of cuttings or embankment a tolerance of +0.25 shall be permitted, i.e. if a slope of 1 in 2 is specified, the acceptable slope shall be not steeper than 1 in 2 or slacker than 1 in 2.25.

(g) Width of Cuttings and Embankments

The tolerance permitted in the width of the bottom of cuttings shall be 200 mm between the centreline of the road and the toe of the cutting slope.

The width of embankments measured horizontally and perpendicular to the centreline of the road at the top of the embankment shall not be less than shown on the Drawing or more than that shown on the Drawing plus 50 mm.

(h) Depth of Side Drains

The difference between road level measured at the centre line of the road and that of the bottom of the side drain measured perpendicular to the centre line of the road shall not deviate from the specified in the drawing by 25 mm.

(3) Rectification of Earthworks and Pavement Layers Exceeding Tolerances



Where any tolerances in Sub-clause 5.2 are exceeded, the Contractor shall assess the full extent of the area which is out of tolerances and shall make good the surface of the pavement course, earthworks or formation in the manner described below.

(a) Earthworks

Where a cut slope is steeper, and an embankment slope is slacker than the specified slope, then the slope shall be trimmed to the specified slope. When the cut slope is slacker, the natural ground slope above top of the cutting and the adjacent cut slopes in both sides of the slacker slope shall be so trimmed that the entire cut slopes match together and they are stable. Where an embankment slope is steeper than the specified slope, then the slope shall be benched and fill material shall be placed and compacted. Subsequently the slope shall be trimmed all in accordance with the requirements of Section 2.0.

Where the width of a cutting is less than, and the width of an embankment is more than the specified width, then the cutting or embankment shall be trimmed to the specified width. Where the width of the cutting is more than the specified width but cut slope is slacker than the specified slope, the slope shall be trimmed as described in the preceding paragraph. If the cut slope is steeper, it shall be trimmed to specified slope. The adjacent slopes shall be also trimmed to make them in harmony. Where the width, of an embankment is less than the specified width, the embankment shall be benched and filled with suitable material and compacted. The slopes shall be trimmed all in accordance with the requirements of Section 2.0

Where the depth of a side drain is less than that specified, the side drain shall be excavated to the specified depth and grade. Where the depth of a side drain is more than the specified depth, the side drain shall be backfilled with suitable material, compacted to a dry density of at least 95% of MDD (Heavy compaction) up to the specified depth or the extra excavated depth shall be made good by the same material of lining of the drain as directed by the Engineer.

(b) Subgrades

Where the levels and or widths are out of tolerance, the full depth of the layer shall be reworked to the Specification. The area to be treated shall be as determined by the Engineer necessary to comply with the Specification.

Where the results of the construction control tests are less than specified the full depth of the layer in the area representing the test shall be reworked to the Specifications. However, if needed, more tests shall be conducted to ascertain the extent of the area required to be reworked.

(c) Base and Subbase

Where these consist of unbound (i.e. natural or graded stone) material the full depth of the material shall be replaced by the material complying with the Specifications. The area treated shall be at least 30m long and 3m wide or such area determined by the Engineer necessary to comply with the Specification.



For bituminous bases the material of the full depth of the layer shall be replaced with fresh approved material laid and compacted to specification. Any area so treated shall be at least 5m long and the full width of the paving laid in one operation.

(d) Wearing Course

The method of rectification shall be adopted depending upon the nature of the failure. Rectification shall be effected either by removing base and replacing with approved material and laying wearing course or re-laying wearing course alone. The Engineer shall instruct appropriate method of rectification. The area rectified shall be the full width of the paving laid in one operation and at least 15m long.

(4) Measurement and Payment

The Contractor shall be deemed to have allowed in his general rates and prices for the cost of complying with the requirements of Clause 5.2.

Notwithstanding the provisions of Sub-clauses 5.2 measurement and payment for earthworks and pavement works shall be made on the basis of the net-cross-Section and/or area basis whichever is applicable ordered by the Engineer or as shown on the Drawing. No additional payment shall be made for any variation. If the executed work is within the limit of tolerance, but is less than as specified on drawing or ordered by the Engineer, the payment shall be made for actual quantity executed, if the executed work is more, the payment shall be made for as shown on the drawing or ordered by the Engineer.

4.3 ADVERSE WEATHER WORKING

(1) No material in frozen condition shall be incorporated in the works, but it shall remain on site for use, if suitable when unfrozen.

(2) Laying of materials containing bitumen, or mixture thereof, shall cease under the following adverse conditions:

(a) during foggy and rainy weather;

(b) when rain is imminent.

(3) While the air temperature is rising, work may be performed at the temperatures of:

(a) 6 degree Celsius with a wind velocity of 25 km/hr

(b) 10 degree Celsius with a wind velocity of 55 km/hr

(4) When the air temperature is falling, works must be stopped as soon as the temperature reaches 6 degree Celsius, regardless of wind velocity. It shall not be resumed until the temperature is definitely rising.

(5) When strong wind is blowing and this is likely to interfere with the proper execution of the work, no surfacing, especially spraying of binder shall be done.

(6) Concrete shall not be placed during falling temperatures when the ambient temperature falls below 7 degree Celsius or during rising temperatures when the ambient



temperature is below 3 degree Celsius. The temperature of the placed concrete shall not be allowed to fall below 5 degree Celsius until the concrete has thoroughly hardened. When necessary, concrete ingredients shall be heated before mixing but cement shall not be heated.

When the ambient air temperature exceeds 40 degree Celsius during the concreting operation, the Contractor shall take measures to control the temperature of the ingredients. Such measures shall include spraying the aggregates stockpile with water to promote cooling down by evaporation and, where feasible, shading of stockpiles and the area where concreting is carried out, reducing time between mixing and placing, and restricting concreting as far as possible to early mornings and late evenings. Curing shall commence after placing of the concrete in order to prevent excessive loss of moisture.

4.3.1 USE OF SURFACES BY CONSTRUCTION TRAFFIC

(1) The loads and intensity of construction traffic used on pavements under construction shall be regulated so that no damage is caused to sub-grade and pavement layers already constructed.

(2) The wheels and track of plant moving over various pavement courses shall be kept free of deleterious materials.

(3) Bituminous base course shall be kept clean and uncontaminated as long as it remains uncovered by a wearing course and surface treatment. Should the base course or tack/prime coat becomes contaminated, the Contractor shall make good by cleaning it to the satisfaction of the Engineer, including removal of the contaminated layer and replacing it as per the requirements of these Specifications which shall be done by the Contractor at his own risk and cost.

4.3.2 CARE OF WORKS

The general obligations for “Care of the Works” shall inter-alia include the following:

(1) Materials shall not be spread on a layer that is wet and may damage it during compaction of subsequent layer or when opened to traffic.

When material is spread out on the road, it shall, be given a good cross-fall and a light compaction on the surface with a steel-tyre roller, in order to facilitate run-off during rainy weather.

(2) All completed works in a layer shall be protected and maintained until the subsequent layer is placed. Maintenance shall include immediate repairs to any damage or defects, which may occur and shall be repeated as often as is necessary to keep the layer continuously intact and in a good condition.

(3) Before priming any completed layer or placing a subsequent layer thereon, any damage to the existing layer shall be repaired so that after repair or reconstruction if necessary, it shall conform in all respects to the requirements specified for that layer. All repair work other than repairs of minor surface damages shall be inspected and tested before covering up.



The previously constructed layer shall also be thoroughly cleaned of all foreign material before construction of a succeeding layer. In the case of bituminous work, the existing layer shall be thoroughly broomed and all dung, clay, mud and other deleterious and loose material shall be removed. Where necessary, the surface shall be sprayed with water before, during and after brooming to remove all foreign material.

Roads shall not be made dirty as a result of construction of works, transportation of equipments, plants, labour and/or materials. In the case the roads are rendered dirty, they shall be cleaned immediately.

4.3.3 MEASUREMENT AND PAYMENT

No measurement and payment shall be made for the works required under this Section. All costs in connection with the requirements specified herein shall be deemed included in the rates and prices of the related items of works in the Bill of Quantities.

4.4 SUBGRADE

4.4.1 SCOPE

This section deals with the treatment of the upper layers of earthworks including preparation and surface treatment of the formation, the addition of layers of selected materials, the improvement of in-situ materials by addition and mixing of selected materials.

4.4.2 DEFINITIONS

The following definitions shall apply to this section and other relevant sections of these Specifications:

(1) Formation Level

The top surface of the subgrade, which supports the construction of pavement.

(2) Subgrade

Upto 300 mm below formation level is designated as "subgrade".

(3) Capping Layers

Capping layers are layers of specified materials to be laid and compacted in the subgrade and below, as required, in replacement of in-situ materials to achieve CBR conforming to Clause 5.4.3.

(4) Stabiliser

The selected natural or crushed material, lime, cement and other similar materials to be mixed into the in-situ material of the subgrade is defined as the "stabiliser".

(5) Mechanical Stabilisation

The addition and mixing of natural or crushed material to improve the in-situ material of the subgrade.

(6) Treated Materials



Following the addition of stabiliser to the in-situ materials, the material is referred to as "treated material." Treated materials shall be mechanically stabilised.

4.4.3 PREPARATION AND SURFACE TREATMENT OF FORMATION (SUBGRADE)

Preparation and surface treatment of formation (subgrade) shall be carried out only after completion of all drainage works unless otherwise agreed by the Engineer and prior to laying the subbase or the base where no subbase is required. The sequence of operations shall be as follows:

(1) Formation of Loose Untreated Materials

Materials for use in the subgrade shall not contain particles larger than 60 mm. In addition the material shall have a CBR of not less than 5% measured after a 4-day soak on a laboratory mix compacted to 95% MDD (heavy compaction), a swell of less than 1%, a plasticity index of less than 40% and an organic matter content less than 3%. In-situ material in the subgrade in cutting that does not meet these requirements shall either be spoiled or, if suitable, placed in the embankment. The spoiled material shall be replaced with material meeting the requirements for loose material in the subgrade.

In fill areas, and in cuttings except otherwise instructed by the Engineer, according to the material encountered, loose materials of the embankments and cuttings shall be deposited in the layers of 150 mm compacted depth. Each layer shall extend reasonably more than the full width of the embankments or cuttings and shall be compacted in accordance with the requirements as specified hereunder:

(a) The material shall be broken down to the above specified grading and any oversize material which cannot be broken down to the required size shall be removed and disposed off. The material shall be scarified and the moisture content shall be adjusted by either uniformly mixing in water or drying out the material such that the moisture content during compaction is between 95% and 100% of the Optimum Moisture Content. The moisture content shall be kept within these limits until compaction is complete except where otherwise instructed by the Engineer.

(b) Each layer shall be compacted to a dry density equal to at least 95% MDD (heavy compaction).

(c) In accordance with Section 3.1.3.4, the Contractor shall submit to the Engineer his proposals for the compaction of the material to be used in the subgrade. The proposal shall be based on the type of plant, the range of passes and the loose depth of the layer.

The Contractor shall carry out site compaction trials, supplemented by necessary laboratory investigations, and shall satisfy the Engineer that all the specified requirements regarding compaction shall be achieved. Site compaction trials shall be completed and approved by the Engineer before the permanent works commences.

(d) Testing to be carried out during the construction of subgrade shall include the following:



The MDD (heavy compaction) and OMC shall be determined for each new material encountered and in every 3000m² or part of it of each layer of compacted subgrade.

The field dry density shall be determined at least once per 500m² or part of it of each layer of compacted subgrade. The test of field density shall be conducted in staggered manner i.e. at left, at crown and at right in the carriageway.

The soaked CBR of material in the subgrade shall be determined at least in every 3000m² or part of it of each layer.

The Contractor shall request in writing for the Engineer's approval for each layer in accordance with Sub-clause 309 (1) and such request shall be accompanied by the tests results of the above described testing and all additional relevant information required. If the results are as specified, he will approve for addition of another layer or will ask for further tests or rework to meet the requirements.

(2) Formation of Loose Treated Materials

The sequence of operation shall be as described in Clauses 5.4.5 to 4.8.7 of this Specification.

(3) Formations in Rock Cuttings

The subgrade in rock cuttings shall be regulated after trimming the rock excavation by a regulating course of minimum 150 mm compacted depth of natural materials complying with the requirements of natural material for sub base.

The regulating course shall be laid, compacted and tested in accordance with Clause 901 and the surface regularity shall meet the requirements of Clause 5.2.

(4) Preparation of Formation for Rehabilitation Works

The formation (subgrade) shall be graded and compacted for construction of pavement in carriageway, shoulders, footpath, and lay-bys. Any soft areas shall be corrected as directed by the Engineer. The prepared surface shall be well cleaned and free from mud and slurry.

(5) Proof Rolling

All subgrade shall be proofrolled with a loaded scraper or truck with a minimum axle load of 8 tonnes. Proofrolling shall be satisfactorily completed before the layer is submitted to the Engineer for approval and shall be carried out in the presence of the Engineer. All proofrolling shall be at the Contractor's expense.

(6) Surface Regularity and Tolerances

The surface regularity and tolerances of the subgrade shall meet the requirements of Clause 5.2.

When each layer is completed the Contractor shall comply with the requirements of Clause 310 for requesting the Engineer's approval and protecting the layer.



4.4.4 RIPPING OFF EXISTING BITUMINIOUS SURFACE USING EXCAVATOR

The existing bituminous surface shall be ripped off using excavator/manual. The same shall be placed back on the full width of the subgrade and rolled as per Section 5.5 to construct an improved subbase of nominal 75-100 mm thickness.

4.4.5 SCARIFYING OF EXISTING BITUMINIOUS SURFACE

Where embankment work is required in order to increase the level of road, the existing bituminous surface shall be scarified using excavator/manual before placing the fill materials over it.

4.4.6 MEASUREMENT

(1) Subgrade construction with loose untreated/treated materials, formation in rock cutting shall be measured in cubic metre by taking cross sections at intervals of 10 metres or as directed by the Engineer in the original position before the work starts and after its completion and computing the volumes of the respective work in cubic metre by average end area method.

(2) Preparation of subgradefor rehabilitationworks shall be measured in square metre.

(3) Capping layer shall be measured in cubic metre by end area method as described in Sub- clause 4.8.7

4.4.7 PAYMENT

The subgrade construction with loose untreated/treated materials, formation in rock cutting, preparation of subgrade, capping layer, mechanically stabilised subgrade shall be paid at their respective contract unit rate which shall be the full and the final compensation to the Contractor for all the materials, labor and machineries involved as per Clause 5.3.3 and also for the cost of:

(1) Arrangement of land for supply source of materials required.

(2) Compacting the ground supporting subgrade where removal and replacement of unsuitable material or loosening and recompacting is involved.

(3) Watering or drying of material in the subgrade as required.

(4) Mixing, spreading in layers brining in appropriate moisture content and compacting to the requirement of Clause 803.

(5) Proofrolling and testing.

(6) All other operations including incidental costs necessary to complete the item as per this Specification.

4.4.8 Payment Item

(1) Preparation of subgrade with proper camber by excavating



earth to depth equal to pavement thickness , consolidation

with roller, disposal of surplus earth within 50m lead m2

4.5 GRANULAR SUBBASE (GSB)

4.5.1 GENERAL

This section covers the construction of mechanically stable subbase with suitable material.

The specification and requirements are based on the recommended criteria given by the UK Transport Research Laboratory’s Overseas Road Note 31 – A Guide to the Structural Design of Bitumen-surfaced Roads in Tropical and Sub-tropical Countries.

4.5.2 SOURCES OF MATERIALS

Subbase materials shall be obtained from approved roadside excavation in borrow or cut or from such other sources of supply as may be specified or approved from time to time for use.

The Contractor shall comply with all requirements of Section 400 in respect of borrow pits.

4.5.3 MATERIAL REQUIREMENTS AND POTENTIAL PROCESSING

The subbase material for this purpose shall be material from an approved source. The source may be river bed or pit gravels, rock quarry, alluvial deposits, crusher-run, or other naturally occurring granular materials meeting the requirements of these Specifications.

Partial processing may include such measures as the use of a bar “grizzly”, or mechanical screening to separate oversize material; crushing or use of a grid or cleated roller to reduce oversize; and/or blending or mechanical stabilization.

The subbase material after placing and compaction shall conform to the following requirements:

The grading of the subbase material after placing and compaction shall be a smooth curve within and approximately parallel to the envelope given in Table 5.5.

Table 5.5-8Grading Envelope for Granular Subbase

Sieve size (mm)Percentage Passing

by Weight

Grading I Grading II

75 100 -

53 - 100

26.5 55-75 50-80

4.75 10-30 15-35

0.075 <10 <10



The fraction passing 0.425 mm sieve shall have a Liquid Limit not more than 25, aPlasticity Index not more than 12 % and Linear Shrinkage not more than 6%.

The CBR of the material, after 4 days soaking, shall not be less than 30% at 97% MDD (Modified Compaction).

4.5.4 COMPACTION TRIALS

Before commencing construction and from time to time as may be considered necessary by the Engineer, the Contractor shall carry out compaction trials in the presence of theEngineer on each main type of materials to be compacted in the Works. The length of the trial section shall be minimum 100 m unless otherwise specified by the Engineer. The Contractor shall carry out all necessary laboratory and field tests and supply the Engineer with the copies of the results of all tests.

Following completion of the compaction trials, the Contractor shall submit to the Engineer, for his approval, proposals for the compaction of each main type of material. The Contractor's proposals shall include reference to the type of equipment, the operating weights and tyre pressures and the method of adjusting moisture content.

If, in the opinion of the Engineer, the results of the compaction trials indicate that the Contractor's proposed plant and methods achieve the densities specified, the Engineer shall approve the same. Otherwise the Contractor shall submit in writing proposals for modifying the plant and/or methods and shall compact further trials in accordance with these modified proposals until the Engineer approves the Contractor's proposals.

4.5.5 PREPARING UNDERLYING COURSE

The subbase shall only be constructed provided that the underlying subgrade layer conforms to the requirements specified in Section 5.5.6 of the Technical Specifications. Immediately before placing the material, the subgrade shall be checked for any damage or deficiencies, which shall be made good.

4.5.6 LAYING AND COMPACTION

The material shall be deposited in such quantity and spread in a uniform layer across the full width required, so that the final compacted thickness is nowhere less than shown on the Drawings or instructed by the Engineer. Every reasonable effort shall be made to prevent segregation during mixing, dumping, spreading, trimming and compacting operations.

The compacted thickness of any layer laid, processed and compacted at one time shall not exceed 150 mm and when a greater compacted thickness is required, the material shall be laid and processed in two or more layers. The minimum layer thickness shall be 100 mm.

The material shall be broken down to the grading specified in Clause 5.5.3. Any oversize material which cannot be broken down to the required size shall be removed and disposed off.The material shall be scarified and the moisture content adjusted by either uniformly mixing with water or drying out the material such that the moisture content during



compaction is between 95% and 100% of the Optimum Moisture Content (IS 2720 Part 8). It shall be graded and trimmed to final line and level.

The final trim shall be in cut and the Contractor shall ensure that material from the trim is neither deposited in low areas nor spread across the section but graded clear of the works. Following the final trim the material shall be compacted to a dry density of at least 95% of MDD (IS 2720 Part 8). During the grading, trimming and compaction of the material the Contractor shall ensure that the surface and/or the material does not dry out. If so, the Contractor is requiredto apply fog sprays of water or other approved means sufficient to maintain the surface and/or material within the specified limits of moisture content.

On completion of compaction, the surface shall be tight and free from movement under compaction plant and free from compaction planes, ridges, cracks, loose or segregated material. If the surface fails to meet the specified requirements, the Contractor shall take corrective measures as set out in the appropriate part of Section 5.4 or such other action as directed by Engineer.

4.5.7 PROOF ROLLING

Unless otherwise directed by the Engineer, the Contractor shall proof roll the completed layer with a steel three wheeled roller applying a load of not less than 5 tonnes per metre width of roll and the layer shall be free from visible movement under the proof roller. Approval of the layer shall only be given after the satisfactory completion of the proof rolling and any remedial measures shall be at the Contractor’s expense.

4.5.8 SETTING OUT AND TOLERANCES

The layer shall be set out and constructed to the appropriate tolerances specified in Section 5.2.

4.5.9 DRAINAGE OF SUBGRADE AND SUBBASE

The subgrade and subbase shall be kept continuously drained and any damage caused by water accumulating on or running off the surface shall be made good at the Contractor’s expense.

Water accumulated on any part of the subgrade or subbase, shall be removed and disposed off. Any material which becomes saturated, or cannot then be compacted to the required density, shall be replaced as specified at Contractor's own expense.

4.5.10 TESTING

(1) Process Control

The minimum testing frequency for the purpose of process control shall be as given in Table 9.2.

Table 5.5-9 Granular Subbase - Minimum Testing Frequency

Tests One test in Every:Minimum no of tests

per section



Material:

Gradation

Atterberg Limits, Shrinkage

Maximum Dry Density and Optimum Moisture Content

Field Density and Moisture Content

200 m3 or part thereof, and change in source

" " " "

1000 m3 " " "

500 m2ofeach layer

2

2

2

2

Construction Tolerances:

Surface Levels

Thickness

Width

10 m

25 m

200 m

-

-

-

(2) Routine Inspection and Testing

Routine inspection and testing shall be carried out by the Engineer to test the quality of materials and workmanship for compliance with the requirements of this section.

Any materials or workmanship not complying with the specified requirements shall be replaced with materials and/or workmanship complying with the specified requirements or be repaired to comply with the specified requirements.

4.5.11 MEASUREMENT

Payment for granular subbase will be on the basis of cubic metres of compacted volume. Compacted volume shall be measured in cubic metre by taking cross Sections at intervals of 10 metres or as directed by the Engineer in the original position before the work starts and after its completion and computing the volumes in cubic metres by average end area method.

4.5.12 PAYMENT

The granular subbase construction shall be paid at the respective contract unit rate for the applicable haul/lead from the approved source and shall be full and final compensation to the Contractor for all the materials, labor and machineries involved as per Clause 5.3.3to complete the work as per the Technical Specifications. In addition to the stipulations under Clause 5.3.3, the contract unit rate shall be also the full and the final compensation for cost of making arrangement for traffic control and other costs required to complete the work and to comply with the requirement of Sections 3.1.3.4.

4.5.13 Payment Item

Providing & laying of Granular sub base course(GSB) to required grade for laying and compacted to required density as per material gradation and aggregate quality-

Granular sub base 250mm thickm3



4.6 BASE COURSE

4.6.1 WET MIX CRUSHED STONE BASE

4.6.2 General

The work shall consist of laying and compacting clean, graded crushed stone aggregate material, premixed with water, to a dense mass on a prepared subgrade/sub-base/base or existing pavement as the case may be in accordance with the requirements of the Technical Specifications. The material shall be laid in one or more layers as necessary to lines, grades and cross-sections shown on the Drawings or as directed by the Engineer.

The thickness of a single compacted Wet Mix Macadam layer shall not be less than 75 mm.

4.6.3 Materials

(a) Aggregates

The aggregate shall be either crushed stone or crushed gravel. The fine aggregate shall be screenings obtained from crushed stone or gravel. The crushed aggregate shall consist of hard, sound, durable and unweathered stone, rocks, and boulders crushed to specified sizes and shall be free from dirt or other objectionable matter and shall not contain soft or disintegrated pieces.

If crushed gravel is used, not less than 90 per cent by weight of the gravel/shingle pieces retained on 4.75 mm sieve shall have at least two fractured faces. The aggregates shall conform to the physical requirements set forth in Table 5.6.3 and Clause 5.6.3 of these Specifications.

Table 5.6-10PhysicalRequirements of Coarse Aggregates for Wet Mix Base Course

Test Test Method Requirements

1 * Los Angeles Abrasion value

or

* Aggregate Impact value

IS: 2386 (Part4)

IS: 2386 (Part4) or IS:5640

Maximum 40 per cent

Maximum 30 per cent

2 Flakiness Indices IS : 2386 (Part 1) Maximum30 per cent3 California Bearing Ratio IS : 2720(Part 16) Minimum 80 per cent4 Crushing Ratio Manual counting & weighing Minimum 80 percent

* Aggregate shall satisfy requirements of either of the two tests.

If the water absorption value of the coarse aggregate is greater than 2 per cent, the soundness test shall be carried out on the material delivered to the site as per IS: 2386(Part-5).

(b) Grading requirements

The aggregates shall conform to the grading given in Table 10.4.

Table 5.6-11Grading Requirements of Aggregates for Wet MixBase Course



Sieve Size (mm) Per cent by weight passing

5037.520

12.54.752.36

0.6000.075

10095-10060-8040-6025-4015-308-220-8

At least 40% of particles retained on a 12.5 mm screen must be angular, irregular or crushed faces.

a) Aggregate Hardness Criteria

Aggregate shall have a minimum soaked (overnight) Ten Percent Fines Value of 50KN or a maximum soaked Aggregate Impact Value of 40.

b) Plasticity of Fines

The fraction passing the 0.425 mm sieve shall have Plasticity Index (PI) not more than 6 %. As an alternative to testing of PI, a maximum Linear Shrinkage of 3% is applicable.

If the PI approaches the upper limit of 6% (4.5<PI<6.0), the fines content shall be restricted to the lower end of the grading range given in a) in accordance with the following criteria:

i) A maximum PP (PI x percentage passing the 0.075mm sieve) of 60, andii) A maximum PM (PI x percentage passing the 0.425mm sieve) of 90.

c) California Bearing Ratio (CBR)

The CBR of the material, after 4 days soaking, shall not be less than 40% at 95% MDD (Heavy Compaction).

4.6.4 Crushing, Screening and Mixing

Unless otherwise instructed, crushing shall be carried out in two stages.

The crushing, screening and proportioning of materials and their subsequent mixing shall be carried out using methods and machines acceptable to the Engineer. To avoid segregation, graded crushed stone shall be moistened when being handled and shall not be stockpiled in heaps higher than 5 m.

If the Contractor wishes to add material from another source in order to achieve the specified grading, the following conditions shall apply:

(a) The Contractor shall be responsible for all costs associated with the provision and mixing of the material, including land acquisition.

(b) The material shall be non-plastic, hard, sharp and durable as specified. The particles shall be free from organic materials, clays and other deleterious substances.



(c) Only material passing the 6.3mm sieve may be added, the percentage to be added shall be agreed with the Engineer and in any case shall not exceed 15% by weight of the mixture.

(d) The minimum crushing ratios as well as other physical requirements as specified in Table 10.2.

Wet mix crushed stone base shall be prepared by an approved method, and shall be mixed to require moisture content prior to loading and transporting to site.

Optimum moisture for mixing shall be determined in accordance with IS:2720 (Part - 8) after replacing the aggregate fraction retained on 20 mm sieve with material of 4.75 mm to 20 mm size. While adding water, due allowance should be made for evaporation losses, However, at the time of compaction, water in the wet mix should not vary from the optimum value by more than agreed limits. The mixed material should be uniformly wet and no segregation should be permitted.

4.6.5 Construction Operations

(a) Preparation of Sub-layer

The surface of the subgrade/sub-base to receive the wet mix crushed stone base course shall be prepared to the specified lines and crossfall and made free of dust and other extraneous material. Any ruts or soft yielding places shall be corrected in an approved manner and rolled until firm surface is obtained if necessary by sprinkling water. Any sub-base/base/surface irregularities where predominant, shall be made good by providing appropriate type of profile corrective course (levelling course).

(b) Provision of Lateral Confinement of Aggregates

While constructing wet mix crushed stone base arrangement shall be made for the lateral confinement of wet mix. This shall be done by laying materials in adjoining shoulders along with that of wet mix macadam layer and following the sequence of operations described in the subsequent sections that follow.

(c) Transportation of Wet Mix

Wet mix crushed stone base materials shall be transported and dumped in such a way that no segregation occurs.

(d) Compaction Trials

The Contractor shall carry out compaction trials in accordance with Clause 5.5.4.

(e) Laying of Wet Mix

The material shall be deposited in such quantity and spread in a uniform layer across the full width required, so that the final compacted thickness is nowhere less than shown on the Drawings or instructed by the Engineer. Every reasonable effort shall be made to prevent segregation during transportation, dumping, spreading, trimming and compacting operations.



In no case should the mix be dumped in heaps directly on the area where these are to be laid nor shall their hauling over a partly completed stretch be permitted.

The wet mix may be spread either by a paver or a motor grader. For portions where mechanical means cannot be used, manual means as approved by the Engineer shall be used. The motor grader shall be capable of spreading the material uniformly all over the surface. Its blade shall have hydraulic control suitable for initial adjustments and maintaining the same so as to achieve the specified slope and grade.

The paver shall be self-propelled, having the following features:

- Loading hoppers and suitable distribution mechanism

- Screed shall have tamping and vibrating arrangement for initial compaction to the layer as it is spread without rutting or otherwise marring the surface profile.

- Paver shall be equipped with necessary control mechanism so as to ensure that the finished surface is free from surface blemishes.

The surface of the aggregate shall be carefully checked with templates and all high or low spots remedied by removing or adding aggregate as may be required. The layer may be tested by depth blocks during construction. No segregation of larger and fine particles should be allowed. The aggregates as spread should be of uniform gradation with no pockets of fine materials.

(f) Compaction of Wet Mix

After the mix has been laid to the required thickness, grade and cross fall/camber the same shall be uniformly compacted, to the full depth with suitable roller.

The compacted thickness of any layer laid, processed and compacted at one time shall not exceed 150 mm and when a greater compacted thickness is required, the material shall be laid and processed in two or more layers. The minimum compacted layer thickness shall be 75 mm.

In portions having unidirectional cross fall/superelevation, rolling shall commence from the lower edge and progress gradually towards the upper edge. Thereafter, roller should progress parallel to the centre line of the road, uniformly over-lapping each preceding track by at least one third width until the entire surface has been rolled. Alternate trips of the roller shall be terminated in stops at least 1 m away from any preceding stop.

In portions in camber, rolling should begin at the edge with the roller running forward and backward until the edges have been firmly compacted. The roller shall then progress gradually towards the centre parallel to the central line of the road uniformly overlapping each of the preceding tracks by at least one-third width until the entire surface has been rolled.



Any displacement occurring as a result of reversing of the direction of a roller or from any other cause shall be corrected at once as specified and/or removed and made good.

Along forms, kerbs, walls, or other places not accessible to the roller, the mixture shall be thoroughly compacted with mechanical tampers or a plate compactor. Skin patching of an area without scarifying the surface to permit proper bonding of the added material shall not be permitted.

Rolling should not be done when the subgrade is soft or yielding or when it causes a wave like motion in the sub-base/base course or subgrade. If irregularities develop during rolling which exceed 12 mm when tested with a 3 metre straight edge, the surface should be loosened and premixed material added or removed as required before rolling again so as to achieve a uniform surface conforming to the desired grade and cross fall. In no case should the use of unmixed material be permitted to make up the depressions.

Rolling shall be continued till the density achieved is at least 98 per cent of the maximum dry density (heavy compaction) for the material as determined by the method as per IS 2720 Part 8.

After completion, the surface of any finished layer shall be well closed, free from movement under compaction equipment or any compaction planes, ridges, cracks and loose material. All loose, segregated or otherwise defective areas shall be made good to the full thickness of the layer and re-compacted.

4.6.6 Proof Rolling

Unless otherwise directed by the Engineer, the Contractor shall proofroll the completed layer with a steel three wheeled roller applying a load of not less than 5 tonnes per metre width of roll and the layer shall be free from visible movement under the proofroller. Approval of the layer shall only be given after the satisfactory completion of the proofrolling and any remedial measures shall be at the Contractor’s expense.

4.6.7 Setting Out and Tolerances

Wet mix crushed stone base course shall be set out and constructed to the tolerances given in Section 5.2

4.6.8 Rectification of Surface Irregularity

Where the surface irregularity of the wet mix crushed stone base course exceeds the permissible tolerances or where the course is otherwise defective due to subgrade soil getting mixed with the aggregates, the full thickness of the layer shall be scarified over the affected area, re-shaped with added wet mix material or removed and replaced with fresh wet mix material as applicable and re-compacted in accordance with this specification.The area treated in the aforesaid manner shall not be less than 5 m long and 2 m wide. In no case shall depressions be filled up with material or fines that are not approved.

4.6.9 Testing

(a) Process Control



The minimum testing frequency for process control shall be as given in Table 10.3 and Section 5.9.12

However, the frequency of tests to be conducted will be as directed by the Engineer.

Table 5.6-12Minimum Testing Frequency

Tests One test in every Min. no of tests per section

Materials:

Gradation

Flakiness Index

Los Angeles Abrasion

Aggregate Impact Value

Crushing Ratio

California Bearing Ratio

Sodium Sulphate Soundness

MDD, OMC

Field Density

200 m3 or part of it and change in source

" " " "

" " " "

"" " "

"" " "


"" " "


500 m2 of each layer

2

2

Section 300

''

"

"

"

2

Construction Tolerances:

Surface Levels

Thickness

Width

Smoothness

10 m

25 m

200 m

40 m2

-

-

-

-

(b) Routine Inspection and Testing

Routine inspection and testing shall be carried out by the Engineer to test the quality of materials and workmanship for compliance with the requirements of this section.

Any materials or workmanship that do not comply with the specified requirements shall be replaced by materials and workmanship complying with the specified requirements, or be repaired so that after being repaired it shall comply with the specified requirements.

4.6.10 Measurement

Wet mix crushed stone base courseshall be measured in cubic metre by taking cross sections at intervals of 10 metres or as directed by the Engineer in the original position before the work starts and after its completion and computing the volumes in cubic metres by average end area method.

4.6.11 Payment

Wet mix crushed stone base courseconstruction shall be paid at their respective contract unit ratefor all the operations, materials, labor and machineries involved and any incidental costs. In addition to the stipulation in Clause 116, the contract unit rate shall be also the full and the



final compensation for cost of making arrangement for traffic control and other costs required to complete the work complying with the requirement of the TS.

4.6.12 Payment Item

Providing & laying wet mix macadam graded aggreagtes base course to required degree of compaction with proper camber by using well graded crushed aggregate premixed with OMC using suitable mixture, motar grader as per material gradation & quality specified-200mm thick

Providing & laying wet mix macadam graded aggreagtes base course to required degree of compaction with proper camber by using well graded crushed aggregate premixed with OMC using suitable mixture, motar grader as per material gradation & quality specified-200mm thick-Wet mix macadam 200mm thick

m3

SECTION 55.0 DAYWORKS



5.1 General

Work shall not be executed on a Daywork basis except by written order of the Engineer. Bidders shall enter basic rates for Daywork items in the Schedules and the rates shall apply to any quantity of Daywork ordered by the Engineer. Unit quantity has been indicated against each item of Daywork, and the extended total for Dayworks shall be carried forward as a Provisional Sum to the Summary. Unless otherwise adjusted, payments for Dayworks shall be subject to price adjustment in accordance with the provisions in the Conditions of Contract.

5.2 Daywork Labor

In calculating payments due to the Contractor for the execution of Dayworks, the payment will be made for the actual number of work hours and not for the travel to and from the site. Only the time of classes of labor directly doing work ordered by the Engineer and for which they are competent to perform will be measured. The time for Charge Hands actually doing the work with the gangs will also be measured but not the time for Foremen or other supervisory personnel.

The Contractor shall be entitled to payment in respect of the total time that labor is employed on Daywork, calculated at the basic rates entered by him in the "Schedule of Daywork Rates, Labor", together with an additional percentage payment on basic rates representing the Contractor's profit, overheads, etc., as described below:

(a) The basic rates for labour shall cover all direct costs to the Contractor, including (but not limited to) the amount of wages paid to such labour, transportation time, overtime, subsistence allowances, and any sums paid to or on behalf of such labour for social benefits in accordance with the laws of the country of the Employer.



(b) The additional percentage payment to be quoted by the Bidder to be applied to costs incurred under (a) above shall be deemed to cover the Contractor's profit on costs, superintendence, liabilities and insurances and other allowances to labour, time-keeping, clerical and office work, the use of consumable stores, water, lighting and power; the use and repair of stagings, scaffolding, workshops and stores, portable power tools, manual plant and tools, supervision by the Contractor's staff, foremen and walking gangers (other than charge hands working with the gang); and other charges incidental to the foregoing.

5.3 Daywork Materials

The Contractor shall be entitled to payment in respect of materials used for daywork (except for materials for which the cost is included in the percentage addition to labor costs as detailed heretofore), at the basic rates entered by him in the “Schedule of Daywork Rates, Materials”, together with an additional percentage payment on the basic rates to cover overhead charges and profit, as follows:

(a) The basic rates for materials shall be calculated on the basis of the invoiced price, freight, insurance, handling expenses, damage, losses, etc., and shall provide for delivery to store for stockpiling at the Site. The basic rates shall be stated in national currency, but payment will be made in the currency or currencies expended upon presentation of supporting documentation.

(b) The additional percentage payment to be quoted by the Bidder to be applied to costs incurred under (a) above shall be deemed to cover the Contractor's profit on costs, superintendence, liabilities and insurances and other charges incidental to the foregoing. Payments under this item shall be made in the currencies and in the proportions as stated in the Summary.

5.4 Daywork Plant

The Contractor shall be entitled to payments in respect of Contractor’s Plant already on Site and employed on daywork at the basic rental rates entered by him in the “Schedule of Daywork Rates, Plant”. Said rates shall be deemed to include due and complete allowance for depreciation, interest, indemnity, insurance, repairs, maintenance, supplies, fuel, lubricants, other consumables, all overhead, profit and administrative costs related to the use of such plant. The cost of drivers, operators, and assistants shall be included in the rates of vehicles and machinery.

In calculating the payment due to the Contractor for Contractor’s Plant employed on daywork, only the actual number of working hours will be eligible for payment. However where applicable and agreed with the Engineer, the contractor would be eligible for payment for the to and fro travel time of the plant/equipment from the part of the site where the Contractor’s Plant was located when ordered by the Engineer to be employed on daywork, to the actual location of the site where such plant/equipment is engaged for the work.
