industrial internship project report-odu paul-14115

8/22/2019 Industrial Internship Project Report-Odu Paul-14115

1/79

INDUSTRIAL INTERNSHIP PROJECT REPORT

OCTOBER 2012APRIL 2013

AT

I.Z.A CONSTRUCTION COMPANY SDN BHD

ODU PAUL DUKU ERIKOLE

14115

DEPARTMENT OF CIVIL ENGINEERING


2/79

i

INDUSTRIAL INTERNSHIP PROJECT REPORT

01ST OCTOBER 201212TH APRIL 2013

SOIL CEMENT STABILIZATION OF PAVEMENT

SUBGRADE FOR A NEW 2.5KM ROAD IN ANAK KURAU

SUBMITTED TO

CENTER FOR STUDENT INTERNSHIP, MOBILITY

AND ADJUNCT LECTURESHIP (CSIMAL)

UNIVERSITI TEKNOLOGI PETRONAS

BY

ODU PAUL DUKU ERIKOLE - 14115

DEPARTMENT OF CIVIL ENGINEERING

APRIL 2013


3/79

ii

HOST COMPANYS VERIFICATION STATEMENT


4/79

iii

EXECUTIVE SUMMARY

The construction of new roads often results in the necessity to cope up with problematic

subgrade materials such as expansive soils, collapsible soils, erodible soils, very soft

soils and wet areas. These problems associated with subgrade materials are common in

many parts of the world, although they tend to be localized in certain areas of which

Kampung Anak Kurau is not an exception.

Most of the soil at the project site is unsuitable (consists of mud/clay) which undergo a

huge amount of volume change due to changes in temperature and moisture. This

shrinking and swelling of the soil can lead to cracking of overlying pavement layers.

According to (Karin, Sven-Erik & Ronny, 2002), a conventional solution in this

situation is soil substitution, which involves excavating the loose soil layers and

replacing them with frictional/granular material of higher bearing capacity. This layer is

then followed by sub-base and base courses which are normally constructed of

aggregates. But fill materials can deteriorate due to intrusion of stone base, pumping of

subgrade soil and infiltration of water from subgrade, leading to a substantial damage of

pavement[5].

Soil substitution is also not cost effective (aggregates are costly) and frequently also

problematic, as the replaced material must be disposed of and new filling material

hauled to the site. Furthermore, soil substitution takes longer time (several layers to be

constructed) and it is not environmentally friendly method due to the greenhouse

emissions during raw material mining, processing, and transportation of raw materials to

the construction site.

This project entitled as Soil Cement Stabilization of Pavement Subgrade for a new

2.5km road in Anak Kurau therefore, aims at improving the strength of subgrade

materials and reducing road construction cost in terms of material, time and

maintenance.

The improvement of the strength of the subgrade materials is through the use of

geotextile to separate the soft subgrade materials from the granular fill materials prevent


5/79

iv

migration and mingling of the soft subgrade soil and granular fill material under the

action of the construction equipment or subsequent traffic but yet allow free movement

of water. This unsuitable subgrade material replacement is then followed by stabilizing

the fill materials with cement.

During the unsuitable soil replacement by using geotextile separator, the unsuitable

material was excavation to a sufficient depth, a type A non-woven geotextiles was

then placed as a separator with a minimum overlap of about 500mm (figure 2.3.4-3),

followed by river sand filling in layers and then compaction.

The untreated fill material was then subjected to in-situ CBR test, Field Density Test,

sieve analysis, Atterberg limits tests and compaction test to determine its properties.

Samples of the granular fill materials were also dosed with different Portland cement

content (2.5%, 3.5% and 5%) at the optimum moisture content and subjected to

unconfined compressive strength (UCS) test so as to determine the optimum cement

content to be used for the stabilization. The UCS test result shows that the strength of the

subgrade material increases with an increase in the cement content and based on this

result, a cement content of 4% was used in the Mix Design for the soil cement

stabilization.

The area to be stabilized is then demarcated and 4% of cement by proportion is added to

the subgrade soil and mixed into it until a uniform color is obtained, and the mixture is

then thoroughly compacted.

Comparison of the CBR values before and after soil cement stabilization shows a

significant increase in the value of CBR after soil cement stabilization. The CBR of the

subgrade before stabilizing with cement is between 19% and 42% while the CBR value

increases to between 78 and 82 at the age of three days and as high as 103% at the age of

seven days after soil cement stabilization. This CBR value is higher than the

recommended CBR value (80%) for road base constructed of crusher run or aggregate

material. For this reason, it is not advisable to have sub-base and base courses, surface

course can be constructed directly on the stabilized subgrade because it (the subgrade) is

strong enough to withstand the subsequent traffic loading from the vehicle that will be


6/79

v

using the road. Soil cement stabilization of the subgrade therefore reduces the design

and construction thickness of flexible pavement.

Based on the cost analysis, it can be concluded that soil cement stabilization is more cost

effective than conventional method of constructing flexible pavement becauseconstruction cost when using soil cement stabilization of the subgrade material is RM

245,000.00 (table 2.4.2-1) but the cost would have been RM 516,390.26 (table 2.4.2-2)

if conventional method were used.


7/79

vi

ACKNOWLEDGEMENTS

I would like to express my sincere gratitude to all those people whose immeasurable

contributions made it possible for me to complete my industrial internship training. I

would like to thank especially the Center for Student Internship, Mobility and Adjunct

Lectureship (CSIMAL) and the Department of Civil Engineering of Universiti

Teknologi PETRONAS (UTP) for giving the students such a golden opportunity to do

industrial internship training and for their well-organized Internship Guidelines which

made work easier for us during our training period. I would also like to thank my UTP

supervisors Dr. Tee Hee Min of UTP for his encouragement and advice during the first

visit and Dr. Mohd Faris Khamidi during the second visit for his support and guidance

about what I need to add to the Internship Report.

I am also thankful to the management of I.Z.A Construction Company for offering me

the opportunity to do my industrial training with the company and for every assistance

that they rendered to me from October 2012 up to date. Special thanks also go to my

host company supervisor, Mr. Mior for assigning me several tasks and always being

available to guide me in executing the tasks. I appreciate the project manager Mr.

Firdaus, site manager Mr. Ravi and the project engineer Mr. Zulhelmy so much for

helping me at site supervision work, in understanding construction drawings and taking

off. I am thanking Mr. Rama of Jabatan Kerja Raya Malaysia (JKR) for his advance and

for always asking me to join him for any laboratory tests and for providing an

explanation for both laboratory and in-situ test results.

Last but not least, I am thankful to all the staff of I.Z.A Construction Company and my

fellow interns in the company for their support especially for providing me with relevant

information that helped me during my training.


8/79

vii

TABLE OF CONTENTS

HOST COMPANYS VERIFICATION STATEMENT........................................................... ii

EXECUTIVE SUMMARY .............................................................................................. iii

ACKNOWLEDGEMENTS ............................................................................................. vi

TABLE OF CONTENTS ................................................................................................ vii

LIST OF FIGURES ....................................................................................................... ix

LIST OF TABLES .......................................................................................................... x

1.0. INTRODUCTION .............................................................................................. 1

1.1. BRIEF DESCRIPTION OF THE HOST COMPANY ......................................................... 1

1.2. OBJECTIVES OF THE INDUSTRIAL INTERNSHIP ......................................................... 1

1.3. SCOPE OF WORK, TASKS OR PROJECTS UNDERTAKEN DURING INTERNSHIP ............ 2

2.0. INTERNSHIP PROJECT REPORT ........................................................................ 6

2.1.0. PROJECT BACKGROUND ..................................................................................... 6

2.1.1. BACKGROUND ..................................................................................................................... 6

2.1.2. PROBLEM STATEMENT ........................................................................................................ 7

2.1.3. SIGNIFICANCE OF THE PROJECT .......................................................................................... 8

2.1.4. PROJECT OBJECTIVE ............................................................................................................ 9

2.1.5. SCOPE OF WORK FOR THE PROJECT ................................................................................... 9

2.2.0. LITERATURE REVIEW ............................................................................................. 10

2.2.1. BRIEF DESCRIPTION OF SOIL CEMENT STABILIZATION...................................................... 10

2.2.2. TYPES OF CEMENT USED TO STABILIZE SOIL ..................................................................... 10

2.2.3. SOILS SUITABLE FOR CEMENT STABILIZATION .................................................................. 11

2.2.4. DESIGN CEMENT CONTENT FOR CEMENT-STABILIZED SOILS ........................................... 11

2.2.5. SOIL CEMENT STABILIZATION PROCESS ............................................................................ 13

2.2.6. OTHER STABILIZING AGENTS ............................................................................................. 13

2.2.7. BENEFITS OF SOIL STABILIZATION (CATERPILLAR, 2006) .................................................. 14

2.2.8. APPLICATION OF SOIL STABILIZATION .............................................................................. 15

2.3.0. METHODOLOGY ............................................................................................... 16

2.3.1. MOBILIZATION OF MACHINERY ........................................................................................ 16

2.3.2. SITE CLEARANCE AND DEMOLITION WORKS .................................................................... 18

2.3.3. EARTHWORKS ................................................................................................................... 18

2.3.4. UNSUITABLE SOIL REPLACEMENT WITH GEOTEXTILE SEPARATOR................................... 19

2.3.5. DRAINAGE WORK .............................................................................................................. 21

2.3.6. MATERIAL SAMPLING, TESTING AND MIX DESIGN ........................................................... 24

2.3.7. GRADING TO PROFILE ....................................................................................................... 25


9/79

viii

2.3.8. SPREADING THE STABILIZING AGENT ............................................................................... 25

2.3.9. PULVERIZING AND MIXING ............................................................................................... 25

2.3.10. PRELIMINARY COMPACTION ............................................................................................. 26

2.3.11. GRADING TO CAMBER ...................................................................................................... 26

2.3.12. FINAL ROLLING .................................................................................................................. 26

2.3.13. CURING ............................................................................................................................. 26

2.3.14. QUALITY CONTROL ............................................................................................................ 27

2.3.15. RECOMMENDATION ......................................................................................................... 27

2.3.16. SITE CLEANING AND DEMOBILIZATION ............................................................................ 27

2.4.0. RESULTS AND DISCUSSION ............................................................................... 28

2.4.1. RESULTS ............................................................................................................................ 28

2.4.1.1. Sieve Analysis ................................................................................................................ 28

2.4.1.2. Dry Density/Moisture Content Relationship for site soil .............................................. 29

2.4.1.3. Atterberg Limits ............................................................................................................ 31

2.4.1.4. Unconfined Compressive Strength (UCS) Test Result................................................... 33

2.4.1.5. CBR Values before Soil Cement Stabilization ............................................................... 35

2.4.1.6. CBR Values after Soil Cement Stabilization .................................................................. 38

2.4.2. DISCUSSION ....................................................................................................................... 40

Cost Benefit Analysis. ..................................................................................................................... 43

2.5.0. CONCLUSION AND RECOMMENDATION ........................................................... 45

2.5.1. CONCLUSION ..................................................................................................................... 45

2.5.2. RECOMMENDATION ......................................................................................................... 46

3.0. SAFETY TRAINING AND VALUE OF THE PRACTICAL EXPERIENCE ...................... 47

3.1. LESSON LEARNED AND EXPERIENCE GAINED ........................................................ 47

3.2. LEADERSHIP, TEAM WORK AND INDIVIDUAL ACTIVITIES ....................................... 49

3.3. BUSINESS VALUES, ETHICS AND MANAGEMENT SKILLS ......................................... 50

3.4. PROBLEMS OR CHALLENGES FACED AND SOLUTIONS TO OVERCOME THEM .......... 51

4.0. CONCLUSION ................................................................................................. 52

REFERENCES .............................................................................................................. I

APPENDICES ............................................................................................................. II

APPENDIX 1 TRAINING SCHEDULE .................................................................................. II

APPENDIX 2

PROJECT GANTT CHART ............................................................................. IIIAPPENDIX 2- LABORATORY REPORT ................................................................................. IV

APPENDIX 3 UNSUITABLE SOIL REPLACEMENT WITH GEOTEXTILE SEPARATOR ............... XI

APPENDIX 4 CULVERT INSTALLATION ........................................................................... XII

APPENDIX 5 SOIL CEMENT STABILIZATION APPLICATION PROCESS ............................... XIV


10/79

ix

LIST OF FIGURES

FIGURE 2.1-1 PROJECT LOCATION PLAN ............................................................................................................... 7

FIGURE 2.3.1-1 SPECIALIZED MACHINE .............................................................................................................. 16

FIGURE 2.3.1-2 SUPPORTING MACHINES............................................................................................................ 17FIGURE 2.3.3-1 ROAD CROSS SECTION IN CUT AND FILL AREAS .............................................................................. 19

FIGURE 2.3.4-1 REASONS FOR DETERIORATION OF FILL MATERIALS .......................................................................... 20

FIGURE 2.3.4-2 IMPORTANCE OF GEOTEXTILE SEPARATOR. ..................................................................................... 20

FIGURE 2.3.4-3 JOINING OF GEOTEXTILE SEPARATOR BY OVERLAP......................................................................... 21

FIGURE 2.3.4-4 TYPICAL DETAILS FOR STANDARD FILL SECTION TREATMENT TYPE 1(SAND REPLACEMENT WITH GEOTEXTILE

SEPARATOR ............................................................................................................................................ 21

FIGURE 2.3.5-1 SUB-SOIL DRAIN CROSS SECTION (CH900CH1150) ................................................................. 22

FIGURE 2.3.5-2 BEDDING TYPE B1,SOFT FOUNDATION ........................................................................................ 23

FIGURE 2.4.1-1 PARTICLE SIZE DISTRIBUTION CURVE ............................................................................................ 28

FIGURE 2.4.1.2-1 DRY DENSITY /MOISTURE CONTENT RELATIONSHIP SITE SOIL ........................................................ 29

FIGURE 2.4.1.2-2 DRY DENSITY /MOISTURE CONTENT RELATIONSHIP RIVER SAND FILL.............................................. 30FIGURE 2.4.1.2-3 DRY DENSITY /MOISTURE CONTENT RELATIONSHIP FOR IMPORTED EARTH FILL................................. 31

FIGURE 2.4.1.3-1 LIQUID LIMIT GRAPH ............................................................................................................. 32

FIGURE 2.4.1.4-1 ULTIMATE STRENGTH DESIGN MIX FOR SOIL AND SAND MIX......................................................... 33

FIGURE 2.4.1.4-2 ULTIMATE STRENGTH DESIGN MIX FOR SOIL .............................................................................. 34

FIGURE 2.4.1.4-3 ULTIMATE STRENGTH DESIGN MIX FOR SAND............................................................................. 35

FIGURE 2.4.2-1 THICKNESS OF FLEXIBLE PAVEMENT BY USING SOIL CEMENT STABILIZATION........................................... 42

FIGURE 4-1 PIE CHART OF BENEFITS OF INTERNSHIP TRAINING ................................................................................. 53


11/79

x

LIST OF TABLES

TABLE 2.2.4-1 CEMENT REQUIREMENTS (QUANTITIES) FOR VARIOUS SOILS (HICKS,2002) ........................................... 12

TABLE 2.2.4-2 MINIMUM UNCONFINED COMPRESSIVE STRENGTH AT 7 DAYS FOR CEMENT AND 28 DAYS FOR LIME, LIME-

CEMENT, AND LIME-CEMENT-FLY ASH STABILIZED SOILS (GUYER,2011). ............................................................ 12TABLE 2.2.4-3 DURABILITY REQUIREMENTS FOR STABILIZED SOIL (GUYER,2011) ....................................................... 13

TABLE 2.4.1-1 SIEVE ANALYSIS RESULTS............................................................................................................. 28

TABLE 2.4.1.2-1 DRY DENSITY/MOISTURE CONTENT RELATIONSHIP FOR SITE SOIL ..................................................... 29

TABLE 2.4.1.2-2 DRY DENSITY/MOISTURE CONTENT RELATIONSHIP FOR RIVER SAND FILL........................................... 30

TABLE 2.4.1.2-3 DRY DENSITY/MOISTURE CONTENT RELATIONSHIP FOR IMPORTED EARTH FILL.................................... 31

TABLE 2.4.1.3-1 PLASTIC LIMIT TEST RESULTS..................................................................................................... 32

TABLE 2.4.1.3-2 LIQUID LIMIT TEST RESULTS...................................................................................................... 32

TABLE 2.4.1.4-1 DESIGN MIX (TRIAL MIX) FOR SOIL-SAND MIXTURE...................................................................... 33

TABLE 2.4.1.4-2 DESIGN MIX (TRIAL MIX) FOR SOIL ............................................................................................ 34

TABLE 2.4.1.4-3 DESIGN MIX (TRIAL MIX) FOR SAND .......................................................................................... 35

TABLE 2.4.1.5-1 CBRVALUES BEFORE SOIL CEMENT STABILIZATION....................................................................... 36TABLE 2.4.1.5-2 CBRVALUES AFTER SOIL CEMENT STABILIZATION......................................................................... 38

TABLE 2.4.2-1 SOIL CEMENT STABILIZATION OF SUBGRADE MATERIALS ..................................................................... 43

TABLE 2.4.2-2CRUSHER RUN ROAD BASE MATERIAL .............................................................................................. 44


12/79

1

1.0. INTRODUCTION1.1. BRIEF DESCRIPTION OF THE HOST COMPANY

I.Z.A Construction Co. Sdn. Bhd was formed on 15th September 1982 and was

incorporated under the Company Act 1965 on the 21st September 1991. The Board of

Directors are Dato' Baharuddin Bin Hj. Mahyuddin, a Civil Engineer and Mr. Farouk

Bin Anwar a Chemical Engineer. Since its formation in 1982, the company due to the

expertise and technical experiences of the directors has secured and completed contracts

well exceeding Ringgit Malaysia 560 million. The company has progressed

tremendously from a small time Class 'D' contractor to a fully-fledged Class 'A'

Bumiputera contractor registered with Contractor Service Centre since 1994. Since then

it has well established itself and received high recognition by the Ministry of Finance

and the Prime Minister's Department with the status COMPETENT CONTRACTOR.

The award of MS ISO 9001:2000 certification by SIRIM QAS International Sdn. Bhd. is

a proven testament of the company systematic management being recognized

internationally.

1.2. OBJECTIVES OF THE INDUSTRIAL INTERNSHIP

To apply theoretical knowledge in industrial application and implement HealthSafety and Environment (HSE) practices at workplace.

To expose the students to ethical and professional work culture, industrialpractices and potential employers

To develop students skills in work ethics, communication, leadership andmanagement

To engage students in real research-based assignments, research-based activitiesand team-work activities

Hands-on training.


13/79

2

1.3. SCOPE OF WORK, TASKS OR PROJECTS UNDERTAKENDURING INTERNSHIP

During my training period, I was tasked with the following tasks which can be divided

into project management, supervision, material testing, health safety and environment,

and reporting.

1. Project managementa. Help the QS in tendering work especially in taking off and in pricing the

tender document.

b. Attend a two days course about Microsoft Project 2010 and then come upwith work programs for assigned task and thereafter do weekly project

tracking

c. Report project progress based on project tracking to the supervisor.2. Supervision

a. Inspect daily site activitiesb. Ensure effective flow of traffic flow is not interrupted by using adequate

temporary traffic signs where necessary.

c. Determine the area for closed turfing and ensure that closed turfing is donefor slope protection in both cut and fill slopes.

4. Material testinga. Check the results for slump test before any concreting is doneb. Ensure that concrete cubes are cast during concreting and follow the JKR

technician to the concrete suppliers laboratory for cube test on the seventh

and 28th day after concreting

c. Carry out speedy test for imported earth to ensure that the moisture content isnot less than 10% and does not exceed 27%

e. Help the technician recommended by JKR during Field Density Test (FDT)f. Coordinate with JKR to inspect California Bearing Ration (CBR) test and

ensure that the CBR value is 5% for soil, 30% for sand and 80% after soil

cement stabilization


14/79

3

5. Health Safety and Environment (HSE)a. Involved in a BOMBA inspection to ensure the safety of occupants of

completed building projects for a period of one week

b. Always wear safety boots and ensure that all the general workers wear safetyboots when carrying out any site activity

c. Ensure that each and every worker at the construction site wears face muskespecially during spreading of the stabilizing agent which can be airborne

when it is windy.

d. Ensure that traffic barriers are in place especially when working at roadintersection to prevent accidents.

e. Ensure that water samples are collected every month for environmental waterquality monitoring.

6. Reportinga. Prepare daily site diary including the daily site activities, workforce at site,

machinery and equipment used, materials delivered to the site, visitors at the

site, and daily weather conditions.

b. Prepare weekly progress report consisting of the site activities for the weekand overall progress, workforce present and those on leave for the week,

materials delivered to the site, machinery and equipment at the site, visitors

at the site and weather conditions for the whole week

c. Take site photos every Friday and make progress photo reportd. Do weekly project tracking and tracking on the 4th, 20th and 30th of every

month

e. Help the project manager in preparing monthly report

The projects that I undertook during my training consists ofunsuitable soil replacementby using non-woven geotextile as a separator, drainage work and soil cement

stabilization. My responsibilities as stated below are all under the direct supervision of

the site manager Mr. Ravi. I performed most of the tasks in his presence and whether he

is around or absent, he double check my work, make changes where necessary and then

ask me to include those changes in my work.


15/79

4

During unsuitable soil replacement by using non-woven geotextile as a separator,

my responsibility is to:

1. Determine the volume of cut materials and granular fill materials based on theexisting ground level and finished road level by using Microsoft office excel.

2. Measure the volume of fill materials from each truck upon arrival at the site andthen compute the total daily volume hauled to the site and report it to the site

manager Mr. Ravi

3. Ensure that unsuitable materials such as roots of trees are removed from the fillmaterials during off hauling and leveling by motor grader.

4. Ensure that, the overlap of geotextiles is as shown in the drawing (figure 3.6)before the geotextile is covered with fill materials.

My responsibility during drainage work is to:

1. Check with the project engineer and site manager the culverts upon arrival at thesite to ensure that the dimensions of each and the total quantities confirm to the

one in the order sheet before unloading.

2. Check the culverts to ensure that the culverts have not been damaged duringdelivery and set aside any damaged culvert during delivery and unloading.

3. Ensure that the unloaded culverts are stockpiled near to where they will beinstalled so as to avoid re-handling and unnecessary equipment movement.

4. Ensure that the culverts are installed in the right location and beddings wereproperly graded to avoid the culverts from settling after being installed

5. Ensure proper alignment and jointing especially for box culverts in order toreduce the migration of soil fines and water between sections of the box culverts

and their surroundings.

6. Determine the volume of materials to be used for bedding preparation and forbackfill of culverts as shown in.

7. Ensure that backfill materials are free from debris, organic matter, wood, frozenmaterial or large stones.

8. Determine the quantity of reinforcement bars required for culvert wingwallsfrom construction drawings and the volume of concrete to be ordered after the


16/79

5

steelwork and formwork for the wingwalls as well as the quantities of bricks,

cement and sand for sumps.

9. Inspect the steelwork and formwork for culvert wingwalls to ensure that thespacing for the steel bars confirms to that in the drawing, the number of steel

bars is as I determined and the formwork is strong enough to withstand the

weight of the fresh concrete.

10. Ensure the safety of the works during unloading and installation of culverts andduring the construction as well as concreting of culvert wingwalls.

Last but not least, my scope of work during soil cement stabilization is to:

1. Check and verify that the proportion of the stabilizing agent is as indicated in themix design

2. Check and verify that mixing or depth of soil cement stabilization is as shown inthe construction drawing

3. Ensure that all the workers wear face mask during spreading of stabilizing agent4. Ensure that soil cubes are cast and FDT conducted for use in the laboratory to

determine the optimum moisture content and maximum dry density

5. Ensure that CBR test is conducted at the age of three days and seven days todetermine the mechanical strength of the subgrade after stabilization with

cement.


17/79

6

2.0. INTERNSHIP PROJECT REPORT2.1.0. PROJECT BACKGROUND

2.1.1. BACKGROUND

This project involves the construction of a new road from Kamunting to Anak Kurau,

Taiping-Perak Darul Ridzuan (figure 2.1-1) and it consists of two phases: - phase 1

involves the construction of a 2.5 Km road starting at state route A137 at Kampung

Anak Kurau while phase 2 involves the construction of an 11Km road connecting the 2.5

Km road to state road A7 at Sungai Relong. Phase 1 uses soil cement stabilizationmethod for the road embankment construction while phase 2 uses the conventional

method of road construction which composes of layers of crushed rock for the road sub-

base and road base courses. This report is entirely about phase 1 of the construction in

which unsuitable soil replacement with geotextile separator precedes the soil cement

stabilization process.

In this project, non-woven geotextiles type A are placed between the soft subgrade and

the granular fill materials so as to filter and hence prevent migration and mingling of the

soft subgrade soil and granular fill material under the action of the construction

equipment or subsequent traffic but yet allow free movement of water. After the

unsuitable soil replacement, a cement content of 4% is added to the soil and mixed into

it until a uniform color is obtained, and the mixture is then thoroughly compacted. This

process called soil cement stabilization is used to increase the strength of the subgrade

materials, thereby elimination the need for sub-base and base courses which is normally

constructed of crusher run, thus resulting into a great cost saving.


18/79

7

Funding for the project is by Kementerian Kemajuan Luar Bandar & Wilayah (KKLW)

and all the project work is done according to the JKR standards & specifications. The

total value of the contract at award to I.Z.A Construction Sdn. Bhd was RM

7,228,925.40. I.Z.A Construction Sdn. Bhd received the contract document on 27th

December 2011 and it started the project work on 09th January 2012 with total project

duration of 53 weeks. Contractually, the project is to be completed on 07th January

2013.

Figure 2.1-1 Project Location Plan

2.1.2. PROBLEM STATEMENT

An efficient road network is a key factor in the development of a region or an area

because it helps in the mobility of people and goods from one place to another. The

construction of this new road by the Malaysia Government will help connect the

residents of Kampung Anak Kurau to Kamunting, Taiping and other parts of the

country. Site condition however poses a serious challenge to the construction work.


19/79

8

Most of the soil at the project site is unsuitable (consists of mud/clay) which undergo a

huge amount of volume change due to temperature and moisture. This shrinking and

swelling of the soil can lead to cracking of overlying pavement layers. According to

(Karin, Sven-Erik & Ronny, 2002), a conventional solution in this situation is soil

substitution, which involves excavating the loose soil layers and replacing them with

frictional material of higher bearing capacity normally well-graded aggregates so as to

obtain a stable sub-grade, sub-base or base layers. Soil substitution is however not cost

effective and frequently also problematic, as the replaced material must be disposed of

and new filling material hauled to the site. Soil substitution also takes longer time and it

is not environmentally friendly method due to the greenhouse emissions during raw

material mining, processing, and transportation of raw materials to the construction site.

2.1.3. SIGNIFICANCE OF THE PROJECT

A well-constructed road must be durable, cost effective, easy to maintain and most of all

it must be able to serve its intended function. This can only be achieved if the road is

constructed on a solid, stable foundation. Mixing cement and or lime into the soil will

help stabilize the soil thus making it denser, waterproof and more stable. Soil

stabilization improves the soil strength and it will be used as a substitute to well graded

aggregates in this project because it takes shorter time to stabilize the soil than using

layers of well-graded aggregates to obtain stable sub-grade, sub-base or base layers. For

this 2.5km road, the soil stabilization process has taken only two weeks. Soil cement

stabilization improves the engineering properties of soil thus making the stabilized base

strong enough to withstand vehicle loading like crusher run base and it is cost effective,

easy to maintain and more environmentally friendly than the conventional method of

road construction. Cost effectiveness here is realized by the fact that soil cement

stabilization eliminates the need to import large volume of aggregates and the associated

production and hauling cost whereas it is more environmentally friendly because it

reduces greenhouse emissions during raw material mining, processing, and

transportation to the site in the conventional method.


20/79

9

2.1.4. PROJECT OBJECTIVE

The objective of this project is to improve the strength of subgrade materials and to

reduce cost of road construction in terms of material, time and maintenance.

2.1.5. SCOPE OF WORK FOR THE PROJECT

The scope of work for this project can be divided into work prior to soil cement

stabilization and soil cement stabilization work.

The work to be done prior to soil cement stabilization include:1. Mobilization of machinery2. Site clearing and demolition of existing structures in the entire area of the

road reserves

3. Earthwork and unsuitable material replacement with geotextile separator4. Drainage work5. Sampling, testing and mix design

Soil cement stabilization work on the other hand consists of:1. Spreading the stabilizing agent2. Weighing to verify proportion of stabilizing agent3. Pulverization and mixing4. Digging to verify the depth of mixing or depth of stabilization5. Preliminary compaction6.

Grading to chamber

7. Final rolling8. Curing9. Cube Casting and Testing, Field Density Test, CBR test

10. Site cleaning and demobilization


21/79

10

2.2.0. LITERATURE REVIEW

2.2.1. BRIEF DESCRIPTION OF SOIL CEMENT STABILIZATIONSoil stabilization and can be defined as the treatment of natural soil to improve its

engineering properties (Garber & Hoel, 2002). Soil cement stabilization is a process to

improve the strength and durability of soil by mixing an appropriate amount of cement

with the soil. This can be achieved by pulverizing the natural soil or borrow material,

adding the appropriate amount of cement to the pulverized soil and mixing it properly

and then thoroughly compacting the mixture. When cement comes in contact with soil

water, it forms calcium silicate hydrate and calcium hydroxide (Ca(OH)2). The calcium

silicate hydrate formed has a strong cementing effect hence binding the soil together and

increasing its strength. The Ca(OH)2 formed results in pozzolanic reactions which

provides a further increment of strength in the longer term (Karin, Sven-Erik & Ronny,

2002).

Both subgrade and road base can be stabilized with cement. The thickness of a cement-

stabilized road base depends upon the traffic loads, traffic volumes and the stability of

the subgrade. The thickness of sub-base or subgrade cement stabilization on the other

hand, depends up-on the nature of the soils and the conditions of the job. Theeffectiveness of soil cement stabilization depends on the type of soil being stabilized, the

quantity of cement added, the degree of mixing, the time of curing, the dry density of the

compacted mixture,

2.2.2. TYPES OF CEMENT USED TO STABILIZE SOIL

Normal (Type I) and Air Entraining (Type IA) Cements are most commonly used typesof cement for soil stabilization. Sulfate Resistant Cement (Type II) and High Early

Strength Cement (Type III) have also been successfully used for cement stabilization of

soils. Each type of cement used for soil stabilization depends on the type of soil and its

contents (Guyer, 2011).


22/79

11

2.2.3. SOILS SUITABLE FOR CEMENT STABILIZATIONMost types of soil can be stabilized with cement ranging from gravelly and sandy soils

to fine-grained silts and clays. It is generally more effective and economical to use it

with granular soils due to the ease of pulverization and mixing and the smaller quantities

of cement required (Hicks, 2002).

Fine-grained soils of low to medium plasticity can also be stabilized, but not as

effectively as coarse-grained soils. It is difficult to mix cement with the soil of PI more

than 30 so in such cases, lime needs to be added first to reduce the PI and improve

workability before adding the cement. For soils that contain sulfates, it is advisable to

use sulfate resistant cement for stabilization of the soils. If the pH of the soil is lower

than 12.1, it is not advisable to use cement to stabilize the soil (Hicks, 2002).

2.2.4. DESIGN CEMENT CONTENT FOR CEMENT-STABILIZED SOILSDetermining the design cement content for cement-stabilized soils involves the

classificationof the untreated soil (table 2.2.4-1) and the determination of the gradation

of the soil to be stabilized and using it to select estimated cement content for moisture-

density tests to determine the maximum dry density and optimum water content of the

soil-cement mixture. Triplicate samples of the soil-cement mixture are then prepared for

unconfined compression and durability tests at the cement content selected. The results

of the unconfined compressive strength and durability tests are compared with the

requirements shown in (table 2.2.4-2 and table 2.2.4-3).

The lowest cement content which meets the required unconfined compressive strength

requirement and demonstrates the required durability is the design cement content.


23/79

12

Table 2.2.4-1 Cement requirements (quantities) for various soils (Hicks, 2002)

Table 2.2.4-2 Minimum unconfined compressive strength at 7 days for cement and 28

days for lime, lime-cement, and lime-cement-fly ash stabilized soils (Guyer, 2011).

Usual Range in Estimated Cement Cement Contents

AASHTO Cement Requirement Content and That for Wet-Dry and

Soil Unified Soil

Percent

by

Percent

by

Used in Moisture-

Density Test Freeze-Thaw Tests

Classification Classification* Volume Weight Percent by Weight Percent by Weight

A-1-a GW, GP, GM, 57 35 5 357

SW, SP, SM

A-1-b

GM, GP, SM,

SP 79 58 6 468

A-2GM, GC, SM,

SC 710 59 7 579

A-3 SP 812 711 9 7911

A-4 CL, ML 812 712 10 81012

A-5 ML, MH, CH 812 813 10 81012

A-6 CL, CH 1014 915 12 101214

A-7 OH, MH, CH 1014 1016 13 111315

Stabilized soil layer Minimum Unconfined Compressive strength, MN/m

Flexible Pavement Rigid Pavement

Base course 5.171 3.447

Sub-base course, select

material or subgrade

1.723 1.379


24/79

13

Table 2.2.4-3 Durability requirements for stabilized soil (Guyer, 2011)

2.2.5. SOIL CEMENT STABILIZATION PROCESSThe basic soil cement stabilization processes include:

Assessment and testing Site Preparation Introduction of cement Mixing Compaction and shaping or trimming Curing

2.2.6. OTHER STABILIZING AGENTSOther soil stabilizing agents that have been used successfully include lime,

bitumen/asphalt, fly ash, granulated blast furnace slag, filler materials.

Lime is used to stabilize medium, moderately fine, and fine-grained clay soils. When

mixed in soil, lime reduces the soil moisture content thus reducing the plasticity of the

soil, making it more rigid. Lime also increases strength and workability of the soil and

reduces the ability of the soil to swell (Caterpillar, 2006).

Bitumen is used in soil stabilization because it makes the soil stronger and resistant to

water and frost. Soil bitumen stabilization benefits from fewer-weather related delays

Type of soil Stabilized Maximum Allowable Weight Loss After 12 Wet-Dry or

Freeze-Thaw Cycles percent of Initial Specimen WeightGranular, PI < 10 11

Granular, PI > 210 8

Silt 8

Clays 6


25/79

14

during construction and makes compaction easier and more consistent (Caterpillar,

2006).

Fly ash is normally mixed with lime and water to stabilize granular materials with few

fines to produce a hard, cement-like mass. It acts as a pozzolan and as a filler to reduce

air voids.

Filler, such as fine sand is added in soil stabilization to increase the number of solid

particles and to fill any voids formed during stabilization. The filler itself does not react

but increases the strength of the soil by acting as a stiffener. Filler material is normally

used in the stabilization of peat and mud, as these soils often require large quantities of

stabilizers thus, replacing part of the stabilizer with inexpensive filler can save costs.

Therefore, there are many stabilizers used in soil stabilization, the effectiveness of each

stabilizer depends on the quantity of the stabilizer, the soil type, storage temperature,

degree of compaction, weather condition and availability of the stabilizer.

2.2.7. BENEFITS OF SOIL STABILIZATION (CATERPILLAR, 2006)

There are several advantages of soil stabilization:

Improved soil strength, improved soil workability and improved durability Cost reduction, dust reduction in work environment and reduction of soil volume

change due to temperature and moisture

Conservation of energy and aggregates materials Waterproofing the soil and improving runoff Functioning as a working platform for the project especially in wet weather Control shrinkage and swell Improve load carrying and stress distribution characteristics Improve substandard materials By-products from industry can be used as raw materials


26/79

15

2.2.8. APPLICATION OF SOIL STABILIZATION

Soil stabilization is used in Yards, parking places, sports grounds, road, andstreet, railway, and cable/pipe channel and storage construction sites

It is used as foundations for buildings pools, landfill areas and bridges It is also use in the protection of adjacent structures, slopes of the rivers, lakes,

roads and earth pressure

Noise embankments and Erosion control and for frost and ground waterprotection layers

Stabilization of very soft soils for tunnel boring


27/79

16

2.3.0. METHODOLOGY

2.3.1. MOBILIZATION OF MACHINERYTwo categories of machinery are used for the execution of the soil cement stabilization

works, these include:

a) Specialized Machine (figure 2.3.1-1)

The specialized machines used in this project are the Stabilizer Spreader and Reclaimer

or Mixer Machine. The reclaimer is a 4-wheel base CATERPILAR machine Model SS-

250 which is equipped with a 300 horse power engine that has a self-propelled hydraulic

rotor drum with mixing chamber that could mix and cut up to depth of 650mm. it is used

for the mixing of soil stabilizer agent with the existing earth/material.

Stabilizer Spreader Reclaimer

Figure 2.3.1-1 Specialized Machine


28/79

17

b) Supporting Machines

Supporting machines are provided by I.Z.A Construction Company Sdn Bhd except

those supporting machines that I.Z.A Construction does not have, such machines are

rented from local supplier when the soil cement stabilization work started. The

supporting machinery used for this project includes: Motor Grader, Vibratory Rollers

and Water Trucks as shown in (figure 2.3.1-2).

Excavator

Excavator has been used in this project to excavate unsuitable materials, excavate for

culvert installation, excavate interceptor and toe drains, and to cut and trim slopes

Motor Grader

The Motor Grader is used for site preparation to remove unwanted vegetation and all the

undergrowth during the site preparation. It is also used to trim and level area in the road

reserve before the compaction of the stabilized materials.

Vibratory Rollers

Vibratory Rollers are used for the compaction of the mixed stabilized materials.

Water Trucks

The Water Trucks are used to supply water to the Reclaimer machine during the mixing

process if the site condition requires and to supply water for curing.

Excavator Motor Grader Vibratory Roller Water Truck

Figure 2.3.1-2 Supporting Machines


29/79

18

2.3.2. SITE CLEARANCE AND DEMOLITION WORKSThe Right of Way (R.O.W) was surveyed and Right of Way Limits were indicated by

wooden pegs. Photographs of structures, landscaping trees and shrubs, fences, telephone,

electrical poles and anything that are payable were then taken before site clearing and

demolition of existing structures commenced. Site clearing of trees, vegetation,

undergrowth, bushes and demolition of existing structures in the entire area of the road

reserve are then carried out by hydraulic excavators from CH O towards increasing

Chainage. Demolished structures consists of two storey brickwork building, one storey

masonry building, two storey masonry building, one storey timber building, two storey

timber building, fences and gates, pipe culverts, box culverts, and inlet/outlet structures

for culvert No.1 which is to be extended.

2.3.3. EARTHWORKSBefore the earthwork commenced, surveying and setting out of center line was carried

out using a theodolite and a tripod for Original Ground Level (OGL) and pegged at 10

meters interval lengthwise. Survey pegs were also placed at the toe limits located at 5

meter away from the center line.

Where the OGL was higher than the finished road level, the road centerline and slope

batters were set out and topsoil stripped, the area is then cut by hydraulic excavators.

The cut materials were then hauled using Dump trucks to the filling area. Slopes

trimming and slope or erosion protection (closed turf) was then immediately carried out

for the slopes formed.

Whereas in areas where the OGL was lower than the finished road level, topsoil was

stripped off up to the filling limits and suitable cut materials hauled by Dump trucks

from the cut area are placed and spread out using back pusher. The filling with suitable

materials was carried out in layers and each layer compaction by vibratory roller until

relative compaction of at least 90% of maximum dry density is obtained.


30/79

19

Figure 2.3.3-1 Road Cross Section in Cut and Fill Areas

2.3.4. UNSUITABLE SOIL REPLACEMENT WITH GEOTEXTILESEPARATOR

Problem with soft subgrade

The stability and the durability of any structure depend on how stable and durable its

foundation is. For this Anak Kurau road project however, the subgrade material is very

weak. It therefore needs to be replaced with granular fill materials which will then be

compacted adequately to obtain a more stable subgrade. But fill materials can

deteriorate, leading to a substantial damage of pavement. Such fill materials deteriorate

due to intrusion of stone base, pumping of subgrade soil and infiltration of water from

subgrade as illustrated (figure 2.3.4-1) [5].


31/79

20

Figure 2.3.4-1 Reasons for deterioration of fill materials

Problem Solution

This problem can be solved by using geotextiles. In road constructions, Geotextiles have

been widely used for filtration and in order to prevent migration and mingling of

materials, yet allowing free movement of water. In this project, a geotextile is used as a

separator by placing it between the soft subgrade and the granular fill material. It acts as

a filter to allow water but not fine material to pass through it, preventing any mixing of

the soft subgrade soil and granular material under the action of the construction

equipment or subsequent traffic [5].

Figure 2.3.4-2 Importance of geotextile separator.

Unsuitable soil replacement by using non-woven geotextile as a separator consists of

excavation of unsuitable material to a sufficient depth, laying a type A non -woven


32/79

21

geotextiles as a separator with a minimum overlap of about 500mm (figure 2.3.4-3),

followed by placement of river sand and then compaction. Filling with suitable fill

materials continues to the specified embankment height as shown in (figure 2.3.4-4) and

the unsuitable soil excavated is then leveled at the sides of roadway.

Figure 2.3.4-3 Joining of Geotextile separator by Overlap

Figure 2.3.4-4 Typical details for standard fill section treatment type 1 (sand

replacement with geotextile separator

2.3.5. DRAINAGE WORK

It is important to ensure that there is an adequate drainage in any road construction in

order to avoid road damage due to both surface water and underground water.

Geotextiles


33/79

22

The drainage works for this project involved the construction of surface and subsoil

drains, installation of new precast box and pipe culvert, extension of existing precast box

culvert at CH 0, construction of sumps and wing walls both as inlet and outlet structures,

not forgetting the excavation and backfilling for such works listed above.

The surface drains for this project involved the excavation of interceptor drains and toe

drains and the installation of precast concrete U-drains.

Sub-Soil Drainage

For sub-soil drains, concrete porous pipes were installed with the details as shown in

(figure 2.3.5-1). The trench to receive the concrete porous pipe is first excavated

followed by placing of geotextile with 300 mm overlap. The porous concrete pipe is

then placed on a less thick aggregate layer and its sides and top also fill with aggregates.

This aggregate layer is again covered with geotextile before filling granular materials

until the finished road level is obtained.

Figure 2.3.5-1 Sub-Soil Drain Cross Section (CH 900CH 1150)


34/79

23

Culvert works

Trench Method is used to install both precast reinforced concrete pipe and box culverts

based on the following procedures:

After the Surveyor provides alignment of the Pipe Culvert, Invert Level, R.O.W.and all necessary point, Temporary diversion of water flow is constructed

The trench to receive the culvert is then excavated, followed by Laying andcompaction of bedding materials.

Pipe or box culvert is then laid and checked for alignment before insertingsubsequent pipe or box culverts. Both sides of culvert are temporary secured using

timber wedges to prevent sideways movement.

Upon completion of installation, both sides of the culvert are backfilledsimultaneously with suitable granular backfill in layer of 150mm thick and

compact to 90% Maximum Dry Density.

Wingwalls and headwalls are then constructed at upstream and downstream of theculvert with concrete G 20/20 and structural steel fabric B 705 placed as bedding

The bedding type and installation locations for all the culvert except the giant culvert is

as shown in (figure 2.3.5-2).

Figure 2.3.5-2 Bedding Type B1, Soft Foundation


35/79

24

2.3.6. MATERIAL SAMPLING, TESTING AND MIX DESIGN

Tests are conducted, both before and during the progress of soil cement stabilization to

ensure compliance with the requirements of the Standard Specification for Road Works

(JKR/SPJ/1988), Guidelines for inspection &Testing of Road Works. The tests are

conducted by MMTS-IETS JOINT VENTURE Building & Construction Materials

Testing Laboratory and by Tasek Soil & Materials Lab Sdn. Bhs (TSML) which is

specialized in soil, concrete and asphaltic concrete testing.

The Laboratory testing carried out on the Untreated Soil samples consisting of Imported

soil fill, river sand fill, and imported soil-river sand mixture includes: Sieve Analysis

(Gradation), Atterberg Limits, Soil Classification, Maximum Dry Density (MDD),Optimum Moisture Content (OMC), Unconfined Compressive Strength (UCS) and

Californian Bearing Ration (CBR).

It is important that those tests are carried out both before and during soil cement

stabilization. Gradation or particle size distribution is particularly important in

determining the stabilizer content; more fines require higher cement content or even

addition of lime before adding the cement. Uniform gradation results in uniform mixing,

uniform compaction and hence uniform strength development. The test method used insieve analysis is MS 30 Part 4: 1995. Atterberg Limits (Plastic Limit, PL and Liquid

Limit, LL) are used to determine active clay content which helps in deciding if there is

need to increase the cement content. The PL and LL test were conducted by following

the test procedure of BS: 1377: Part 2: 1990, Clause 4.5. Moisture-density relationship

is used to determine the degree of compaction of the material, high densities obtained is

an indication that the shear strength and elastic modules improved and the ingress of

water is reduced. Finally, CBR and UCS tests are used to determine the strength of the

soil attained.

Determination of the Mix Design is by trial and error. To determine the mix design

(required cement content) for the soil cement stabilization, different dosage of cement

(2.5%, 3.5% and 5% cement) is admixed with the untreated material thoroughly until a

uniform color is obtained, the optimum moisture content is then added. Specimens were


36/79

25

then prepared for UCS test which was conducted at the age of 3 days and 7 days, the

results obtained are shown in (table 2.4.1.4-1, table 2.4.1.4-2 & table 2.4.1-4) and for

soil, sand and soil mixed with sand respectively.

2.3.7. GRADING TO PROFILE

Before the commencement of the soil cement stabilization work, the exposed platform is

checked for reduced level to ensure that the reduced level of the working platform is

within 12mm of the design level for the base of next layer. Where the reduced level of

the working platform is not within 12mm, motor Grader was used to level and grade

the existing material to the required new profile.

2.3.8. SPREADING THE STABILIZING AGENT

After the surface was leveled and graded with motor grader, the determined stabilization

area was marked and the required quantity of cement was spread over the areas to be

stabilized. Spreading of the stabilizing agent was done using a purpose built additive

spreader to the design percentage at a spreading rate of +/-5 % absolute value.

2.3.9. PULVERIZING AND MIXING

Pulverizing and dry (primary) mixing by use of a purpose built Reclaimer- Stabilizer

CMI RS500 to the design depth starts after spreading of the stabilizing agent on the

prepared platform has reached a length of +/-60 meters and a minimum width of 3.0

meters. Where necessary, water is added during mixing through the mixing chamber of

the Reclaimer- Stabilizer CMI RS500 to ensure that the moisture content of the mix

materials does not fall below 2% of Optimum Moisture Content (OMC). The secondary

mixing (called wet run) is to ensure the chemical reaction between the stabilizing agent


37/79

26

and existing material and to ensure the highest density of the mixture after compaction

since maximum Dry Density (MDD) is achieved at OMC.

2.3.10.PRELIMINARY COMPACTIONA Vibratory Roller was used for preliminary compaction to enable the Motor Grader to

work on the loose stabilize material. Vibratory roller with 10 metric tons static mass

ideal was used with rolling pattern of two (2) static passes and six (6) vibration passes.

The critical variable in achieving densification with minimum effort is moisture content

of the material being compacted. Compaction by vibratory roller is continued until a

maximum Dry Density (MDD) of 95% or more is achieved as confirmed by laboratorytest results. Final Rolling is then done using pneumatic tire roller after grading to

chamber to ensure a better compaction and surface.

2.3.11.GRADING TO CAMBER

A Motor Grader was used to grade and form the desired camber; undulations were also

eliminated by the motor grader. The grading and shaping of the stabilized treated layer is

done to ensure that the finished levels are within +/- 6mm of the required reduced levels.

During the process of grading and shaping, the vibratory roller is used for the

compaction.

2.3.12.FINAL ROLLINGFinal rolling is done after grading or trimming and shaping. Pneumatic tire roller is used

for the final rolling so as to ensure a better compaction and surface.

2.3.13.CURING

Curing was done for seven days after soil cement stabilization. Curing is to increase the

rate of hydration of the cement used as stabilizing agent and to prevent rapid setting. The

main purpose of curing is so as to obtain the intended/required/design strength after


38/79

27

cement stabilization and to maintain a uniform temperature of the stabilized subgrade to

prevent thermal shrinkage cracking.

2.3.14.QUALITY CONTROL

Testing was carried out accordingly during the soil cement stabilization work. The tests

that have been carried out during the stabilization process include:

Field Density Test to determine the degree of compaction of the stabilized layer, Moisture Content test is done both before and after mixing to ensure the

relativity of moisture to the mix. This is because the best mixing when using

cement is at the Optimum Moisture Content and so is the Maximum Dry

Density,

Cube test, UCS test to give an indication of the tensile strength of the materialafter stabilization and

CBR test to evaluate the mechanical strength of the subgrade materials afterstabilization.

2.3.15.RECOMMENDATION

1. It is not advisable to proceed with the stabilization under the following climaticconditions:

2. The ambient temperature is below 50C or above 380C3. It is raining or likely to rain4. The wind is sufficiently strong to cause the additive to become airborne5. During conditions that may cause danger to people, property or the environment

2.3.16.SITE CLEANING AND DEMOBILIZATIONUpon completion of the soil cement stabilization work, all waste materials which

resulted from the work is disposed to a dump site approved by JKR, construction

machinery demobilized from the site before and the project handed over for the

pavement works.


39/79

28

0

20

40

60

80

100

120

0 5 10

% Passing

Sieve Size

Particle Size Distribution Curve

2.4.0. RESULTS AND DISCUSSION

2.4.1. RESULTS

2.4.1.1. Sieve Analysis

Test Conditions; Temperature: 28.60C Relative Humidity: 53%

Table 2.4.1-1 Sieve Analysis Results

Figure 2.4.1-1 Particle Size Distribution

Curve

Sieve Size Weight

Retain

ed

%

Retained

%

Passing

50.0 mm

37.5 mm

28.0 mm

25.0 mm

20.0 mm

14.0 mm

12.5 mm 0.0 0.0 100

10.0 mm 44.6 3.7 96.3

6.30 mm 47.8 4.0 92.3

5.00 mm 42.2 3.5 88.8

3.35 mm 51.3 4.3 84.5

2.36 mm 57.6 4.8 79.7

1.18 mm 43.3 3.6 76.1

0.600 10.1 0.8 75.3

0.425 1.9 0.2 75.1

0.300 3.3 0.3 74.8

0.150 3.6 0.3 74.5

0.075 4.0 0.3 74.2

Pan 0.0Weight Before Wash: 1200.5 grams

Weight After Wash: 309.7 grams


40/79

29

2.4.1.2. Dry Density/Moisture Content Relationship for site soil

Test Condition: Temperature = 29.40C, Relative Humidity = 57% & Volume 998.4 cm

3

Table 2.4.1.2-1 Dry Density/Moisture Content Relationship for site soil

Figure 2.4.1.2-1 Dry Density / Moisture Content Relationship site soil

Test No. 1 2 3 4 5

Mass of Soil + Mould (g) 7533 7632 7701 7745 7688

Mass of Mould (g) 5395 5395 5395 5395 5395

Mass of Compacted Soil (g) 2138 2237 2306 2350 2293

Bulk Density of Soil (Mg/m3) 2.141 2.241 2.31 2.354 2.297

Container No. B17 B5 B13 B3 B10

Mass of Container + Wet Soil (g) 139.4 125.3 140.6 148.8 164.2

Mass of Container + Dry Soil (g) 123.8 110.2 122.8 126.8 137.9

Mass of Container (g) 36.3 35.5 38.3 38.1 37.6

Mass of Dry Soil (g) 87.5 74.7 84.5 88.7 100.3

Mass of Moisture (g) 15.6 15.1 17.8 22 26.3

Moisture Content (%) 17.8 20.2 21.1 24.8 26.2

Measurement uncertainty for Moisture content (%) 0.33 0.39 0.34 0.33 0.29

Dry Density (Mg/m3) 1.817 1.864 1.908 1.886 1.82

Measurement uncertainty for Dry Density (Mg/m3) 0.005 0.005 0.005 0.004 0.004

1.8

1.82

1.84

1.86

1.88

1.9

1.92

1.94

0 5 10 15 20 25 30

Dry Density

(Mg/m3)

Moisture Content (%)

Dry Density/Moisture Content Relationship for Site Soil

MDD = 1.839 Mg/m3

s= 1.316 Mg/m3 OMC = 22.7 %

OMC = Optimum

Moisture Content

MDD = Maximum

Dry Density

s = Bulk density

of calibrating sand


41/79

30

Table 2.4.1.2-2 Dry Density/Moisture Content Relationship for River Sand fill

Test Condition: Temperature = 29.90C, Relative Humidity = 62% and Volume 949 cm

3

Figure 2.4.1.2-2 Dry Density / Moisture Content Relationship River Sand fill

Test No. 1 2 3 4 5


Mass of Mould (g) 5478 5478 5478 5478 5478


Bulk Density of Soil (Mg/m ) 1.862 2.083 2.339 2.238 2.078

Container No. C2 C8 C13 C18 C19




Mass of Dry Soil (g) 102.8 114.7 89.1 108.6 92.3

Mass of Moisture (g) 5.00 7.10 7.60 11.00 11.40



Dry Density (Mg/m3) 1.776 1.962 2.155 2.032 1.850


1.7

1.8

1.9

2

2.1

2.2

0 2 4 6 8 10 12 14

Dry Density

(Mg/m3)


Dry Density/Moisture Content Relationship for River Sand

MDD = 2.156 Mg/m3

s=1.186 Mg/m3

OMC = 8.4 %


42/79

31

Table 2.4.1.2-3 Dry Density/Moisture Content Relationship for imported earth fill

Test Condition: Temperature = 29.90C, Relative Humidity = 63% and Volume 949 cm

3

Figure 2.4.1.2-3 Dry Density / Moisture Content Relationship for imported earth fill

2.4.1.3. Atterberg Limits

Test No. 1 2 3 4 5


Mass of Mould (g) 5395 5395 5395 5395 5395


Bulk Density of Soil (Mg/m3) 1.889 2.018 2.184 2.136 2.022

Container No. 17 24 28 32 34




Mass of Dry Soil (g) 38.8 29.3 43.1 30.4 30.5

Mass of Moisture (g) 5.2 4.8 8.2 6.7 7.6



Dry Density (Mg/m3) 1.666 1.734 1.836 1.750 1.619


1.6

1.65

1.7

1.75

1.8

1.85

0 5 10 15 20 25 30

Dry Density

(Mg/m3)


Dry Density/Moisture Content Relationship for Dark Brown

Sandy Clayed Silt

MDD = 1.839 Mg/m3

s=2.80 Mg/m3

OMC = 19.5 %


43/79

32

0

10

20

30

40

50

60

70

0 10 20 30 40 50

Moisture

Content (%)

Number of Blows

Liquid Limit Graph

Test Condition: Temperature = 29.40C, Relative Humidity = 57 & Test Date:16/10/2012

Table 2.4.1.3-1 Plastic Limit Test Results

Plastic Limit Test No. 1 2

Container No. A2 A4

Mass of Container + Wet Soil (g) 26.4 25.1Mass of Container + Dry Soil (g) 24.1 23.1

Mass of Container (g) 15.0 15.4

Mass of Moisture, M1 (g) 2.3 2.0

Mass of Dry Soil, M2 (g) 9.1 7.7

Moisture Content (M1 / M2) X 100 (%) 25.3 26.0

Measurement uncertainty for Moisture content (%) 3.2 308.0

Average Moisture Content (%) 25.6

Table 2.4.1.3-2 Liquid Limit Test Results

Liquid Limit Test No. 1 2 3 4 5Number of Blows 11.00 17.00 30.00 37.00 47.00

Container No. A1 A3 A7 A5 A9




Mass of Moisture, M1 (g) 5.50 5.50 4.40 5.00 4.30

Mass of Dry Soil, M2 (g) 9.10 9.50 8.30 9.90 9.40

Moisture Content (M1 / M2) X 100 (%) 60.40 57.90 53.00 50.50 45.70

Measurement uncertainty for Moisturecontent (%)

3.63 3.44 3.86 3.20 3.31

Figure 2.4.1.3-1 Liquid Limit Graph

Proportion Retained on

425 um Sieve:

Liquid Limit (LL): 5

Plastic Limit (PL): 26

Plastic Index (PI): 29


44/79

33

2.4.1.4. Unconfined Compressive Strength (UCS) Test Result

Table 2.4.1.4-1 Design Mix (Trial Mix) for Soil-Sand Mixture

Water-

Cement

Ratio

Weight

(Kg)

Nominal Size

L x W x H

(mm)

Condition

of

Spacemen

Max.

Load

(KN)

Type of

Failure

Density

(Kg/m3)

Ultimate Strength

(MN/m2) at

3 days 7 days

5%

Cement

6.910 150x150x150 Dry 128.6 Normal 2047 0.6 5.7

3.5%

Cement

7.125 150x150x150 Dry 102.4 Normal 2111 0.8 4.6

2.5%

Cement

7.140 150x150x150 Dry 62.3 Normal 2116 1.3 2.8

Figure 2.4.1.4-1 Ultimate Strength Design Mix for Soil and Sand Mix

0

1

2

3

4

5

6

0 2 4 6 8

Ultimate Strength

(MN/m2)

Age (days)

2.5% Cement

3.5% Cement

5% Cement


45/79

34

Table 2.4.1.4-2 Design Mix (Trial Mix) for Soil

Water-

Cement

Ratio

Weight

(Kg)

Nominal Size

L x W x H

(mm)

Condition

of

Spacemen

Max.

Load

(KN)

Type

of

Failure

Density

(Kg/m3)

Ultimate Strength

(MN/m2) at

3 days 7 days

5%

Cement

5.710 150x150x150 Dry 80.4 Normal 1692 0.3 3.6

3.5%

Cement

5.705 150x150x150 Dry 48.6 Normal 1690 0.6 2.2

2.5%

Cement

5.260 150x150x150 Dry 20.5 Normal 1559 1.2 0.9

Figure 2.4.1.4-2 Ultimate Strength Design Mix for Soil

0

0.5

1

1.5

2

2.5

3

3.5

0 2 4 6 8

Ultimate Strength

(MN/m2)

Age (days)

2.5% Cement

3.5% Cement

5% Cement


46/79

35

Table 2.4.1.4-3 Design Mix (Trial Mix) for Sand

Water-

Cement

Ratio

Weight

(Kg)

Nominal Size

L x W x H

(mm)

Condition

of

Spacemen

Max.

Load

(KN)

Type

of

Failure

Density

(Kg/m3)

Ultimate Strength

(MN/m2) at

3days 7days

5%

Cement

6.610 150x150x150 Dry 75.2 Normal 1959 0.4 3.3

3.5%

Cement

6.490 150x150x150 Dry 47.5 Normal 1923 0.8 2.1

2.5%

Cement

6.310 150x150x150 Dry 40.2 Normal 1870 1.1 1.8

Figure 2.4.1.4-3 Ultimate Strength Design Mix for Sand

2.4.1.5. CBR Values before Soil Cement StabilizationJack/Load rig no. 0.0318 KN/div

Mass of Surcharge: 4.5 kg Test date: 5/3/2013

0

0.5

1

1.5

2

2.5

3

3.5

4

0 2 4 6 8

Ultimate Strength

(MN/m2)

Age (days)

2.5% Cement

3.5% Cement

5% Cement


47/79

36

Table 2.4.1.5-1 CBR Values before Soil Cement Stabilization

CH 10, Before Soil Cement Stabilization

Jack/Load rig no. 0.0318 KN/div


Penetration of Force on Plunger Standard CBR Value

Plunger (mm) Load Guage KN Force (KN) (%)

0 0 -

0.5 35 1.11

1 80 2.54

1.5 120 3.82

2 150 4.77

2.5 175 5.57 13.24 42.03






0 0 -

0.5 30 0.95

1 60 1.91

1.5 100 3.18

2 130 4.13

2.5 160 5.09 13.24 38.43






0 0 -

0.5 40 1.27

1 56 1.78

1.5 70 2.23

2 87 2.77

2.5 100 3.18 13.24 24.02






0 0 -

0.5 30 0.95

1 55 1.75

1.5 80 2.54

2 110 3.50

2.5 130 4.13 13.24 31.22


48/79

37






0 0 -0.5 10 0.32

1 20 0.64

1.5 31 0.99

2 43 1.37

2.5 52 1.65 13.24 12.49

CH 1260, Before Soil Cement Stabilization (same for CH1510)





0 0 -0.5 20 0.64

1 30 0.95

1.5 40 1.27

2 50 1.59

2.5 55 1.75 13.24 13.21






0 0 -0.5 30 0.95

1 60 1.91

1.5 75 2.39

2 85 2.70

2.5 95 3.02 13.24 22.82






0 0 -0.5 30 0.95

1 52 1.65

1.5 65 2.07

2 83 2.64

2.5 90 2.86 13.24 21.62


49/79

38

2.4.1.6. CBR Values after Soil Cement Stabilization



Table 2.4.1.5-2 CBR Values after Soil Cement Stabilization

CBR at CH 115, three days after soil cement stabilization


Mass of Surcharge: 4.5 kg

Penetration of Force on Plunger Standard

Plunger (mm) Load Guage KN Force (KN) CBR Value

0 0 -

0.5 165 4.25

1 274 7.06

1.5 340 8.76

2 420 10.82

2.5 430 11.08 13.2 83.95

3 475 12.24

3.5 490 12.63

4 501 12.91

4.5 510 13.14

5 515 13.27 20 66.36Ave. 75.15

CBR at CH 125 three days after soil stabilization



0 0 -

0.5 81 2.09

1 160 4.12

1.5 250 6.44

2 330 8.502.5 410 10.57 13.20 80.04

3 460 11.85

3.5 495 12.76

4 520 13.40

4.5 530 13.66

5 555 14.30 20.00 71.51

Average 75.78


50/79

39

CH 150, Age: 3days after Soil Cement Stabilization




0 0 -

0.5 139 3.581 220 5.67

1.5 290 7.47

2 361 9.30

2.5 429 11.06 13.2 83.75

3 475 12.24

3.5 520 13.40

4 594 15.31

4.5 615 15.85

5 625 16.11 20 80.53

Average 82.14

CH 110, Age: 7days after Soil Cement Stabilization




0 0 -

0.5 185 4.77

1 283 7.29

1.5 420 10.82

2 517 13.32

2.5 580 14.95 13.2 113.23

3 623 16.05

3.5 654 16.85

4 680 17.52

4.5 710 18.30

5 725 18.68 20 93.42

Average 103.32


51/79

40

2.4.2. DISCUSSION

Sieve analysis is used to determine the gradation of the soil which is a very important

element used in the determination of the proportion of the stabilizing agent. A well

graded soil makes an excellent soil cement and requires the least amount of cement forits stabilization as compared to a poorly graded soil. The sieve analysis result shows that

the soil at the site is well graded as indicated by the particle distribution curve (figure

2.4.1-1).

As shown in (figures 2.4.1.2-1, 2.4.1.2-2 and 2.4.1.2-3), the optimum moisture content is

22.7%, 8.4% and 19.5% for site soil, river sand and imported earth respectively.

Maximum dry density for each soil type is obtained at the respective optimum moisture

content. For this reason, mixing of the stabilizing agent into the soil at the time of

stabilization will be done at those moisture contents. Water will be added during mixing

if the moisture content is found to be lower that the optimum moisture content and thesoil will be dried by application of pressurized air if it is too wet. During the process of

soil cement stabilization, traces of water in the hand are indications that the optimum

moisture content is exceeded.

Since the PI obtained is 29% which is greater than 10% and less than 30%, cement can

be used to stabilize the soil at this project site. If PI is found to be more than 30%, it is

not advisable to used cement alone to stabilize the soil because it is difficult to mix

cement with the soil of PI more than 30% except when lime is first added to reduce the

PI and improve workability before adding the cement (Hicks, 2002).

As shown in (table 2.2.4-2), the minimum Unconfined Compressive Strength (UCS) for

cement stabilized soil at the age of 7 days is 5.171 MN/m2 and 1.723 MN/m2 for base

course and sub-base course or subgrade respectively. Table 2.2.4-2 therefore serves as a

reference for the Mix Design of cement content to be used for the subgrade stabilization.

To determine the Mix Design, Samples of soil, sand and soil-sand mixture were

thoroughly mixed with 2.5%, 3.5% and 5% cement content until a uniform mixture of

soil-cement, sand-cement and soil-sand plus cement at Optimum Moisture Content

(OMC) is obtained. The OMC for site soil, river sand fill material and imported earth fill

material are 22.7%, 8.4% and 19.5% respectively.

Cubes were then cast and Cube and UCS Tests were conducted at the age of 3 days and

7 days to determine the density and the UCS and the results obtained for UCS test are

shown in (table 2.4.1.4-1, table 2.4.1.4-2 & table 2.4.1-4) for soil, sand and soil mixed

with sans respectively.


52/79

41

Table 2.4.1.4-1, table 2.4.1.4-2 and table 2.4.1-4 show that the UCS for 3.5% cement

content at the age of 7 days are 2.1 MN/m2 for soil, 2.2 MN/m2 for sand and 4.6

MN/m2 for soil-sand mix. All these values of UCS are higher than the minimum UCS

(1.723 MN/m2) for cement stabilized subgrade at the age of 7 days shown in (table

2.2.4-2). This proves that a cement content of 3.5% is sufficient enough to stabilize the

subgrade for this project but a cement content of 4% has been used to ensure very stable

subgrade is obtained.

The result of CBR test shows a significant increase in the CBR values of the subgrade

after soil cement stabilization. The CBR value obtained before cement stabilization is

between 12.49% and 42% (table 2.4.1.5-1). The different CBR values obtained before

stabilization is due to the different types of subgrade materials and different degree of

compaction. For the different soil types, JKR specification recommend a CBR value of

5%, 30% and 80% for soil, sand and aggregates respectively. The effect of the

degree of compaction is indicated by the fact that the CBR value obtained is highest at

CH10 which is just at the beginning of the new road and the lowest CBR is attained at

CH2260 which is close to the end of the road. The highest CBR value obtained at CH10

is due to adequate compaction by the construction trucks used to transport construction

materials to increasing chainage along the road.

Just three days after soil cement stabilization, the average CBR value increased to

between 78% and 82% and at the age of seven days, the average CBR of the cement

stabilized subgrade is 103% as shown in (table 2.4.1.5-2). This CBR value is higher the

80% CBR recommended for aggregate road base course and since CBR value measures

the mechanical strength of the subgrade, this high CBR obtained shows how strong the

subgrade is after been stabilized with cement. It is this improved strength of the

subgrade that results in the reduction of the total thickness of the pavement. The

reduction in thickness is as shown in (figure 2.4.2-1) which compares the cross sections

of flexible pavement constructed by conventional method to the one constructed with

cement stabilization of the subgrade materials


53/79

42

Figure 2.4.2-1 Thickness of flexible pavement by using soil cement stabilization

Since the subgrade is strong enough to withstand vehicle loading, sub-base and base

courses will be eliminated and the binder course is going to be spread directly on the

subgrade after an application of prime coat to facilitate its bonding to the subgrade. The

surface course will then be overlaid on the binder course after application of tact coat

also to facilitate bonding of the two layers. This pavement work is scheduled to start on

the 20th

April 2013.

Eliminating the base and sub-base courses conserves aggregate material and the

environment by eliminating the greenhouse gas emission associated with aggregatemining, procession and transportation to the site. This also eliminates traffic congestion

and noise pollution which would have resulted from construction trucks used to haul the

crushed stones to the site.


54/79

43

Cost Benefit Analysis.

Table 2.4.2-1 Soil Cement Stabilization of subgrade materials

Task Description Length

(m)

Width

(m)

Area

(m2)

Rate

(RM/m2)

Amount

(RM)

Spread stabilizing agent,

pulverize and mix with

subgrade material, compact

and grade to chamber

2500.00 7.00 17,500 14.00 245,000.00

The sub-contractor, Specialized Pavement Malaysia (SPM) Sdn. Bhd. has accepted to do

the soil cement stabilization work with rate and amount shown in table 2.4.2-1 which is

the same as that provided in the Bill of Quantity. SPM has its own manpower and all the

necessary machineries and equipment to carry out the cement stabilization of the

subgrade materials. The cement stabilization of the subgrade materials will be followed

by an application of the prime coat and then construction of binder and surface courses.

If conventional method of constructing flexible pavement is used, the subgrade

materials will be compacted to 95% or more of the maximum dry density (MDD)

without any additive based on JKR specification. As shown in (figure 2.4.2-1a), this

compacted subgrade material is normally followed by sub-base, base, binder and surface

courses. The sub-base and base courses are constructed of crusher run while the binder

and surface courses used the same materials and machineries whether for conventional

method or for soil cement stabilization method. The sub-base course c

industrial internship project report-odu paul-14115

Documents