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TRANSPORTATION MATERIALS SAMPLING

(TMS)

HIGHWAY TECHNICIAN CERTIFICATION PROGRAMUniversity of Wisconsin-Platteville 049 Ottensman Hall • 1 University Plaza Platteville WI 53818-3099Office phone: 608.342.1545 Fax: 608.342.1982

PREFACE

The WisDOT Certified Aggregate Sampling Technician Course Manual was prepared and developed by the Highway Technician Certification Program staff at the University of Wisconsin-Platteville, the Highway Technician Certification Program instructors, and other contributors from WisDOT and the highway industry. The information contained in this course manual is intended to be used to train WisDOT personnel to conduct ONLY SAMPLING of aggregates on all types of WisDOT highway construction projects. The intent of this manual is to provide AASHTO-based training as it applies to aggregate sampling. It is the responsibility of the WisDOT Certified Aggregate Sampling Technician to follow all current WisDOT specification parameters and procedures when conducting work assignments for the Wisconsin Department of Transportation.

The WisDOT Certified Aggregate Sampling Technician course manual was developed with these valuable resources:

1. ASTM D 3665 – Standard Practice for Random Sampling of ConstructionMaterials

2. WisDOT Construction and Materials Manual (C & M Manual)3. WisDOT Standard Specifications for Highway and Structure Construction4. Supervisors Safety Manual, Fifth Edition5. The Aggregate Handbook, National Stone, Sand, and Gravel Association6. Portland Cement Concrete Materials Manual, FHWA7. Hot-Mix Bituminous Paving Manual, FHWA

ACKNOWLEDGEMENTS

The HTCP Certified Transportation Materials Sampling Manual committee members have been instrumental contributors to the contents of this course manual. The committee members are:

Robert Jewell – The Kraemer Company Eric Zeinert – Michels Materials Jeff Michalski – WisDOT North Central Region John Brophy – WisDOT North Central Region Deb Bischoff-WisDOT QMP Engineer Jeff Merten- UW-Platteville Russ Frank – WisDOT Bureau of Technical Services Dan Reid – WisDOT Bureau of Technical Services

WisDOT Technical Assistance Hotline Representative:

Russell Frank, WisDOT, Bureau of Technical Services (608.246.7942)

Course Introduction ii

TABLE OF CONTENTS

Course Overview TOPIC A Safety Considerations TOPIC B Aggregate Properties for Base Course TOPIC C ASTM D 3665 Standard Practice for Random Sampling Aggregates TOPIC D WisDOT Aggregate Sampling Procedures TOPIC E Hot Mix Asphalt-Truck Box Sampling Lab Exam Laboratory Exam QMP Award/ Corr. / Eval. Expanded QMP Award, Corrections and Course Evaluation Wisconsin Department of Transportation Standard Specifications http://wisconsindot.gov/Pages/doing-bus/eng-consultants/cnslt-rsrces/rdwy/stndspec.aspx Wisconsin Department of Transportation CMM http://wisconsindot.gov/Pages/doing-bus/eng-consultants/cnslt-rsrces/rdwy/cmm.aspx Wisconsin Department of Transportation QMP http://wisconsindot.gov/Pages/doing-bus/eng-consultants/cnslt-rsrces/qmp/default.aspx

http://wisconsindot.gov/Pages/doing-bus/eng-consultants/cnslt-rsrces/rdwy/stndspec.aspx

http://wisconsindot.gov/Pages/doing-bus/eng-consultants/cnslt-rsrces/rdwy/stndspec.aspx

http://wisconsindot.gov/Pages/doing-bus/eng-consultants/cnslt-rsrces/rdwy/cmm.aspx

http://wisconsindot.gov/Pages/doing-bus/eng-consultants/cnslt-rsrces/qmp/default.aspx

Course Introduction iii

8:00 – 8:15 Registration, Introductions, Course Objectives, Course Syllabus 8:15 – 8:30 Safety Considerations 8:30 – 9:30 Aggregate Properties for Base Aggregate Dense (BAD)

FHWA Segregation Video 9:30 – 9:45 Break 9:45 – 10:45 ASTM D 3665 Standard Practice for Random Sampling Aggregates, Hot Mix Asphalt-Truck Box Sampling, Data entry 10:45 – 11:45 Laboratory Demonstration of WisDOT Aggregate Sampling Procedures

Sample Size Requirements

Sampling from Stopped Conveyor Belt

Sampling from a Conveyor Belt Discharge

Sampling from Stock Piles

Sampling from Roadbed Windrows

Sampling after being Placed Roadbed 11:45 – 12:45 Lunch Break 12:45 – 1:45 Laboratory Student Hands-on Practice WisDOT Aggregate Sampling Procedures


Sampling from Stopped Conveyor Belt


Sampling from Stock Piles

Sampling from Roadbed Windrows

Sampling after being Placed Roadbed 1:45 – TBA Practical Laboratory Student Examination TBA Break TBA Review for Written Examination TBA Written Examination Adjourn

Course Introduction iv

Introduction The Highway Technician Certification Program (HTCP) welcomes you to the Certified Transportation Materials Sampling Technician course. This course requires eight hours of classroom/laboratory attendance. The course content will cover safety considerations; aggregates properties for base aggregate dense (BAD); ASTM D 3665 standard practice for random sampling; WisDOT aggregate sampling procedures; and WisDOT standard specifications Sections 301, 305, 310, 311 and 501 for aggregate gradations. Course Prerequisites None required. A person may earn 0.8 continuing education units (CEU’s) upon successful completion of this course. Certification Requirements The written examination will be limited to a maximum duration of one (1) hour. The written examination will be “open book and open notes” and will consist of true/false and multiple-choice questions, and essay problems. A student will be required to obtain a passing score of 70 percent to be certified as an Aggregate Sampling Technician. Recertification Requirements Recertification is mandatory every three (3) years. The HTCP will send a recertification notice to each certified technician and the firm or agency before the expiration date of the highest certification level(s) of certification obtained. The certified technician must apply for recertification before the expiration date of the highest level(s) obtained. Each certified technician is responsible for obtaining his/her recertification. Recertification may be obtained in one of the following ways:

Complete the next level certification course: A certified technician can obtain recertification by enrolling and successfully completing the next level certification course.

Comprehensive Recertification Exam: Technician can attend the last day of any relevant certification course offered on the course schedule and take the comprehensive recertification exam or come to a remote comprehensive site held throughout the state.

Class at a reduced fee: Opportunity to come back through classroom training to recertify at a reduced fee. A person may earn 0.8 Continuing Education Units (CEUs) upon successful completion of this course.

Revocation/Suspension of Certification Upon written request from any individual, firm, agency, or contractor associated with the HTCP, the HTCP director will provide technical assistance in investigating any alleged

Course Introduction v

report(s) of either certified technician incompetence or act(s) of malfeasance. The HTCP director will then notify WisDOT of the report findings concerning certified technician incompetence or misconduct.

Course Introduction vi

Highway Technician Certification Program Goal The principle goal of the Highway Technician Certification Program (HTCP) is to certify that individuals have demonstrated the abilities to engage in quality control/quality assurance activities in highway work contracted by the Wisconsin Department of Transportation (WisDOT). Introduction of Course Participants At this time, you will be asked to introduce yourself, company name, years of service to the highway construction materials industry, and your present occupational duty. What do you expect from this Training Course? This is your opportunity, as a course participant, to ask the course instructor to cover any other topics related to the Certified Aggregate Sampling Technician course. Please list and identify topics below: Duties and Responsibilities of a Transportation Materials Sampling Technician: The duties and responsibilities of a Transportation Materials Sampling Technician are:

Know the safety, handling, and storage requirements for the equipment.

Know how to collect non-biased aggregate samples utilizing ASTM D 3665 Random Sampling mathematical method.

Know who is responsible for sampling, where samples, minimum frequency of sampling, and sample size for specified designation.

Know the proper WisDOT sampling aggregate procedures.

Be able to procure, properly label, and promptly deliver appropriate size samples to specified designation.

Course Introduction vii

Definitions and Terminology

Aggregate An inert mineral material such as sand, crushed gravel, crushed stone, or combinations thereof.

Absorption The process of a solid taking up liquid into its interior by capillarity.

Base Course The layer or layers of specified or selected material of designed thickness placed on a subbase or a subgrade to support a surface course.

Blue Tops Wooden hubs or stakes driven into the subgrade to indicate the finished subgrade elevation.

Borrow Suitable material from sources outside the right-of-way limits of the project, used primarily for embankments.

Coarse Aggregate Aggregate predominately retained on the No. 4 sieve.

Dense Graded Aggregate

A well-graded aggregate proportioned to contain a relatively small percentage of voids.

Crushed Gravel Crushed angular particles of gravel retained on a No. 10 sieve.

Crushed Stone Crushed angular particles of quarried rock retrained on a No. 10 sieve.

Density The weight per unit volume of a material, usually expressed in pounds per cubic foot.

Embankment The mound of soil, soil-aggregate, or broken rock constructed above the embankment foundation and below the subgrade.

Fine Aggregate Those aggregates which entirely pass the 3/8" sieve, almost entirely pass the No. 4 sieve, and are predominately retained on the No. 200 sieve.

Fineness Modulus A numerical value obtained by adding the total percentages of a sample of the aggregate retained on each of a specified series of sieves and then by dividing the sum by 100.

Gradation

A general term used to describe the composition by size of the aggregate particles in a mixture. It is usually expressed as the proportion (percent) of the aggregate that will pass a series of designated standardized sieves.

Granular Backfill Backfill of a specified gradation and consisting of sand, gravel, crushed gravel, crushed stone, or other fragmented material.

Moisture Content The proportion of moisture present in a material, expressed as a percentage of the oven-dry weight of the material.

Moisture-Density Relationship

The effect of moisture content on the density of a soil compacted according to specified conditions.

Nominal Maximum Particle Size

The nominal maximum size as indicated by the appropriate specification or description. If the specification or description does not indicate a nominal maximum size (for example a sieve size indicating 90-100% passing), use the maximum size (that sieve or size indicating 100% passing).

Open Graded Aggregate

A well-graded aggregate containing little or no fine aggregate and with a relatively large percentage of voids.

Optimum Moisture Content

The moisture content at which a particular soil will be brought to the greatest density obtainable with a specified compactive effort.

Pavement Structure

The combination of subbase, base course, and surface course placed on a subgrade to support the traffic load and distribute it to the road bed.

Course Introduction viii

Definitions and Terminology (continued) Pit A deposit of sand and gravel that can be s excavated by mechanical

means such as with a loader or backhoe.

Plastic Limit

The moisture content which is the boundary between the moldable and semi-solid states of consistency of a soil. It is defined as the moisture content at which a soil will just begin to crumble when rolled into a thread approximately 1/8-inch in diameter.

Quarry A deposit of ledge rock from which the rock is excavated by cutting or blasting.

Quartering A method of reducing the size of a sample with segregation.

Red Tops Wooden hubs or stakes driven into the base course to indicate the finished base course elevation, in preparation for final surface course.

Roadbed The graded portion of a highway which is contained within top and slide slopes and is prepared as a foundation for the pavement structure and shoulders.

Roadbed Material The material below the subgrade in cuts and fills (embankments) and in embankment foundations extending to such depth as affects the support of the pavement structure.

Sand Granular material almost entirely passing the No. 4 sieve and predominately retained on the No. 200 sieve.

Segregation Nonuniform distribution of the various particle sizes within an aggregate.

Sieve In materials testing work, a screen or series of screens have a standardized square opening and are used for subdividing a material into separate successive sizes.

Splitting Reduction in the size of a material sample preparatory to testing by means of a standardized method.

Stationing

A system used to specify the relative position of any point along the reference line. The starting point is usually designed with some arbitrary value, for example, 10 + 00 or 100 + 00, although 0 + 00 can be used. If the beginning point was 10 + 00, the first stake 100 ft. along the line from it would be designated 11 + 00, the one 200 ft. the line 12 + 00, and so on. The term full station is applied to each of these points set at 100-ft increments. A point located between two full stations, say 84.9 ft. beyond station 17 + 00, would be designated 17 + 84.9. Thus locations of intermediate points are specified by their nearest preceding full station and their plus. In the designation of state 17 + 84.9, the plus is 84.9.

Statistically Random Sampling

Sampling at times or at locations determined in advance by the use of a table of numbers so arranged that every digit has an equal chance of occurring.

Subbase Course The layer or layers of specified or selected material of designed thickness placed on a subgrade to support a base course.

Subgrade The top surface of an earthen roadbed upon which the pavement structure and shoulders are constructed.

Course Introduction ix

Acronyms Pertaining to Aggregates: AASHTO American Association of State Highway & Transportation

Officials AMRL AASHTO Materials Reference Laboratory ASTM American Society for Testing & Materials BAD Base Aggregate Dense CAA Coarse Aggregate Angularity ESAL Equivalent Single Axle Load FAA Fine Aggregate Angularity HMA Hot-Mix Asphalt JMF Job Mix Formula PCC Portland Cement Concrete QC Quality Control QMP Quality Management Program QV Quality Verification RAP Recycled Asphalt Pavement SGC Superpave (or SHRP) Gyratory Compactor SHA State Highway Agency SHRP Strategic Highway Research Program SSD Saturated Surface Dry

TOPIC A: Safety Considerations

TOPIC A: Safety Considerations Page A-2

A.1 Project Safety Precautions Safety is of prime importance while serving your occupational duty on the Wisconsin Department of Transportation (WisDOT) construction projects. Approximately 15% of all accidents are caused by unsafe mechanical or physical conditions. The other 85% of accidents result from absentmindedness, negligence, or ignorance of risk. No mysteries should surround an accident. All personnel involved with the project must be able to identify potentially dangerous situations and be prepared for preventive corrective action. A.2 Diagnosis of Any Accident There are five key elements in the diagnosis of any accident: 1. The agency or source of the accident, [the item(s) directly related to the accident] 2. The type of accident [manner in which the person(s) were injured] 3. The unsafe condition [unsafe practice of person(s)] 4. The unsafe act (unsafe practice of the person) 5. The body part and kind of injury Each contributing element should be carefully analyzed and reported so a plan of corrective action can be developed and carried out to prevent future unnecessary accidents. While conducting your occupational duties on your project, remember to keep in mind the following considerations: A.3 Personal Protection Equipment and Apparel The following personal protection safety equipment is required for all construction personnel:

o Eye protection o Ear protection o Hard hat o High visibility safety vest o Steel toed boots o Long pants

Safety vests are what make you visible to construction and public traffic and should be worn at all times. The Wisconsin Department of Transportation has minimum standards for this equipment. This apparel must meet the Performance class 2 or 3 requirements of the ANSI/ISEA 107-2004 standards. Class 2 is required on all projects and an example is shown in the above photo. A class 3 vest with sleeves and pants is required when on a project during nighttime hours.


It cannot be stressed enough that the safety vest provides you visibility in very busy construction zones. Materials sampling and testing is very dirty work and this vest will get dirty and reduce your visibility. Regular washing of the vest is recommended and the vest should be replaced on a regular basis throughout the construction season

A.4 Know Your Safety Officer o Emergency Phone Numbers o Nearest Hospital Location

A.5 Equipment Operators

o Always keep good eye contact with operators when working close to heavy equipment.

A.6 Legal Background Subsection 107.7 of the Standard Specifications requires the contractor to comply with all federal, state, and local laws governing safety, health and sanitation, and to provide necessary safety devices, protective equipment and safeguards. The contractor shall also take all action reasonably needed to protect the life and health of employees on the job and the safety of the public. Wisconsin Statute 101.11 requires every employer to furnish safe employment and a safe place of employment for employees and frequenters. The employer shall furnish and require the use of safety devices, protective devices and safeguards, shall adopt and use methods and processes reasonably adequate to render the employment and the pace of employment safe, and do everything reasonably necessary to protect the life, health, safety and welfare of employees and frequenters. (Note: A frequenter is anyone who is not an employee of the contractor or not a trespasser.)

The Occupational Safety and Health Administration (OSHA), of the U.S. Department of Labor, is empowered to adopt rules or orders, having the full force of law, necessary for the safety and welfare of employees in the private sector. Thus, employees of the contractor and subcontractors are protected by the OSHA rules. OSHA administers and enforces their own rules. The Mine Safety and Health Act of 1977 and all applicable provisions of Title 30, Code of Federal Regulations are required when entering any mine, quarry, or sand and gravel operation. The Wisconsin Department of Safety Professional Services (DSPS) is empowered under Wisconsin Statute 101.055 to adopt safety rules or orders, having the full force of law, necessary for the safety and welfare of public employees. Thus, employees of the state, county, town, city and other political subdivisions of government are protected by the rules of DSPS. DSPSadministers and enforces their own rules.

Under the Worker’s Compensation Act, which is administered byDSPS, a death benefit or compensation for an injury shall be increased if the employer failed to comply with adopted rules or orders of DSPS or OSHA. The death benefit or compensation for an injury shall be reduced if the employee failed to use safety devices required by DSPS or OSHA and provided by the


employer, or if injury results from the employee’s failure to obey any reasonable safety rule adopted and enforced by the employer (Wisconsin Statutes 102.57 and 102.58).

A.7 Quarry & Gravel Pit Safety Precautions All outside personnel must immediately check in at office before entering mine property.

All outside personnel must be accompanied by mine quarry personnel while on mine property

A.8 Sampling at Quarry & Gravel Pit Operations Sampling, production or stockpile, is never performed by outside personnel.

Due to moving conveyors, mobile equipment, and unstable stockpiled materials, all sampling at mining operations must be performed by qualified company personnel

A.9 The Work Zone Once you enter the work zone it is your job to be seen and watch out for yourself. Be alert and always be aware of your surroundings. Work zones are very busy and congested. Be aware that in today’s work environment the most common thing that diverts construction personnel’s attention away from what is happening in the work zone is their cell phone. It is recommended that all cell phone usage be done from the safety of your vehicle. Public Traffic You have two different traffic streams to be aware of public traffic and construction traffic. When working next to a live stream of public traffic always assume that the drivers are inexperienced and unskilled in driving through construction zones and/or that they are inattentive or impaired. Stay alert and avoid complacency with the public at all times. Construction Equipment and Traffic Truck drivers and equipment operators have a job to do and they are concentrating on accomplishing it. Therefore, never assume that the driver or operator sees you. It is highly recommended that you always make eye contact with that person and have them acknowledge your presence before advancing closer to the equipment or behind it. For example, the two most common pieces of equipment on a highway construction project are the dump truck and the front end loader. Both of these pieces of equipment are large and contain blind spots and sight restrictions. The following charts are from the Occupational Safety and Hazard Administration and outline what the operator of these two pieces of equipment can see:


The dark gray areas are those areas where objects or people less than three feet in height cannot be seen by the operator. This is significant for materials testing and sampling personnel because you have your equipment set up on the ground and are usually crouching or on your knees performing the tests. The cross hatched yellow areas is the visibility that the operator has with the mirrors on the vehicle. Note that on the dump truck the rear of the truck is blind to the driver. This reinforces the need for materials sampling and testing personnel to be very cautious when entering the stream of construction traffic to obtain the sample of aggregate or concrete.

TOPIC B: Aggregate Properties for Base Aggregate Dense (BAD)

TOPIC B: Aggregate Properties for Base Aggregate Dense Page B-2

B. 1 Description of Aggregates Aggregate is any hard, inert material used in graded sizes (fine to coarse), which are a part of the hot mix asphalt (HMA) pavement, Portland cement concrete (PCC), or aggregate base course. Aggregate is also referred to as rock, gravel, mineral, crushed stone, slag, sand, rock dust and fly ash. Several types of aggregate, which are available, are given below. Aggregates are also produced by crushing, screening, and grading to required sizes. Material which has been salvaged from old concrete pavements and structures as well as from asphaltic pavements. Aggregates, depending on use, have certain desired physical and chemical properties. These are given later in this section on aggregates used in HMA and base courses. Types of Aggregates

Natural

Pit or Bank Run

Processed

Recycled

Synthetic

B.2 Natural Aggregates Natural rocks occur either as outcrops at or near the surface or as gravel deposit usually along an old streambed. They are classified into three groups: igneous, metamorphic, and sedimentary. These classifications are based on the way the rocks were formed and they will not be further discussed here. Natural aggregates can be Pit or Bank-Run Aggregates or Process Aggregates.


B.3 Pit or Bank-Run Aggregates These include both gravel and sand, which are taken directly from the deposit without processing. B.4 Processed Aggregates These include pit or bank-run aggregates which have been crushed to make it more suitable for construction products (HMA, PCC and Base Aggregate Dense). Crushing normally improves the particle shape by making the rounded particles more angular. Crushing can also improve the size distribution and range. Crushed stone is also a processed aggregate. It is created when the fragments of bedrock and large stone are crushed so that all particle faces are fractured. The crushed stone can be sized by screening; and the rock dust, which results from crushing, can be removed by washing. This rock dust can be used as crushed sand or as mineral filler in HMA. B.5 Recycled Aggregates Reclaimed asphalt pavements (RAP) and concrete pavements both contain valuable aggregates. The aggregate, if of good quality when placed, is most likely still of good quality and it can be reused in HMA pavements or in base courses. The properties desired of an aggregate, whether from RAP or from concrete pavements, or virgin material, are the same. These properties are given in the section on aggregates for HMA. Typically, HMA mixtures may contain recycled materials. It is important that mixtures containing recycled materials meet the same specification that would be required of a virgin mixture. B.6 Synthetic Aggregates Aggregates produced by altering both the physical and chemical properties of a material are called synthetic or artificial. Aggregates are lightweight aggregate, which is produced by heating clay to a very high temperature, and slag, which is normally produced in the blast furnace during steel production. Synthetic aggregates are sometimes used in HMA. B. 7 Rocks and Minerals Naturally occurring aggregates are a mixture of minerals and rock. Minerals are defined as naturally occurring inorganic substances of a definite chemical composition and a specific crystalline structure. Rocks are generally composed of one or more minerals. Rocks compose most of the coarse aggregates and mineral composes most of the fine aggregates. B. 8 Aggregate Sources Aggregate sources are generally gravels and crushed stone. Naturally occurring aggregates are called gravels. Sometimes gravels are put through a crushing operation to reduce their size or to


improve their shape. Some artificial aggregates, which include glass beads, Styrofoam beads, etc., are used but they are generally for specific purpose concretes such as lightweight concrete. B.9 Quarries and Gravel Pits About half of the aggregates used in the United States come from sand and gravel deposits (pits). The other half come from quarry rock that has been put through a crusher. B.10 Natural Fine Aggregate Natural fine aggregate is simply the smaller fragments that result when the edges of rocks are worn away. Due to the way it is formed, natural sand is generally quite round. If there is a shortage of natural sand, manufactured sand may be used. These are generally much more angular, however, and may cause different working characteristics in the concrete. B.11 Gradation Analysis Grading of aggregates is the distribution of particles among various sizes. The gradation is determined by doing an analysis with a set of sieves. Sieves are stacked with larger sizes on top. Gradation is usually expressed in terms of a percentage passing or a percentage retained on the various sieves.


B.12 Coarse Aggregate Sieves To make testing of aggregates more manageable, the aggregates are generally divided into classifications; coarse aggregate and fine aggregate. The distinction between these two size classes is based on whether or not the aggregate will pass a particular sieve. The most common sieve used for this purpose for concrete is the 4.75 mm (No. 4) sieve. This sieve has openings, which are just slightly smaller than a lead pencil. Any aggregates not passing this sieve are classified as coarse aggregates. Any aggregates passing this sieve are classified as fine. This slide depicts typically sieves used in a coarse aggregate analysis.

Course Aggregate Sieves SI Units

US Units

37.5 mm 1-1/2 inch

25.0 mm

1 inch

19.0 mm

3/4 inch

12.5 mm

2 inch

9.50 mm

3/8 inch

4.75 mm

No. 4 (0.187 inch)

B.13 Fine Aggregate Sieves There are many sieve sizes that could be used for analysis of fine aggregates. This is a listing of some of the most commonly used sieves for fine aggregates associated with highway work. Notice that each sieve is about one-half the size of the sieve above it. This assures you that there will be no gaps in your gradation analysis.

Fine Aggregate Sieves

SI Units

US Units

4.75 mm

No. 4 (0.187 in.)

2.36 mm

No. 8 (0.0937 in.)

1.18 mm

No. 16 (0.0469 in.)

0.600 mm

No. 30 (0.0234 in.)

0.300 mm

No. 50 (0.0117 in.)

0.150 mm

No. 100 (0.0059 in.)

0.075 mm

No. 200 (0.0029 in.)


B.14 Results of Sieve Analysis The results of the sieve analysis are sometimes plotted on a gradation chart. An experienced inspector can tell a great deal about the character of a concrete mix by examining the gradation chart. Limits or ranges are usually specified for the percentage of material passing each sieve. Improper sampling technique will affect gradation analysis.


B.15 Objectives of Aggregate Sampling The objectives of sampling aggregates are to ensure and maintain the integrity of what is being sampled. Properly procured aggregate samples are crucial to determining representative test results. Warning: “the use of improper sampling techniques and equipment may affect the actual results of the aggregate product quality. Also, valuable project productivity time and other personnel may be affected by ignoring specified WisDOT sampling methods and procedures.” Improper sampling techniques:

Could affect the actual results of the aggregate product quality (pay adjustments).

May lead to increased product quality troubleshooting issues.

May affect productive cooperative trusting working relationships. B.16 Aggregate Sampling Concerns There are three potential sampling concerns, which may affect the way aggregate samples are procured. The aggregate sampling concerns are related to segregation, degradation, and contamination. B. 17 Segregation Segregation occurs when larger coarse particles separate from smaller, finer sized particles. Segregation occurs anytime the combined aggregate is moved. There is no real cure to totally avoid segregation problems between different sized particles. However, use extreme care to avoid segregated areas while obtaining representative aggregate samples. B. 18 Degradation Degradation is the physical, chemical, and environmental conditions, which can cause a breakdown of the aggregate structure. For example: As a certified AGGTEC sampling technician, you will be required to sample aggregate material off a roadbed. It is extremely crucial to ensure the procured sample will be taken and collected prior to compaction by heavy equipment. Compaction by heavy equipment will change the particle shape of the aggregate, causing the introduction of increased fines into the aggregate sample. In turn, the additional fines generated by the compaction of the heavy equipment will not represent the actual roadbed material, which was placed. Sampling compacted roadbed material may contribute to erroneous test results. B. 19 Contamination Contamination occurs when foreign material is subjected into the aggregate sample being procured. Aggregate sample contamination may occur at anytime while producing the sample on a project. Extreme care and attention to details must be exercised to avoid sample contamination. For example, aggregate sampling from the road, a certified AGGTEC sampling technician must know the depth of crushed aggregate base course before producing aggregate sample. Sampling below the depth of the crushed aggregate base will lead to sample contamination, thus procuring a misrepresentative aggregate sample

TOPIC C: ASTM D 3665 – Standard Practice for Random Sampling

TOPIC C: ASTM D 3665 C-1

Definitions

Contractor Process Control Testing - contractor testing taken at the contractor’s initiative for process control. (Non-random) Engineer Directed Testing - testing performed by the contractor as requested by the engineer. (also non-random) Independent Assurance - separate unbiased review, performed by the Department, to evaluate the sampling and testing of the quality control and verification technicians including personnel qualifications, procedures, and equipment. Quality Control Testing - testing performed by the contractor and used by the Department for product acceptance. The methods and minimum frequencies shall be as specified in the appropriate provision. Verification Testing - independent sampling and testing performed by the Department to validate the quality of the product.

Sample Size Aggregate sampling for obtaining minimum sample sizes shall be in accordance with the CM Manual. The use of larger samples should be considered by the QC staff to increase the probability of obtaining a respective sample. When split samples are required by the provision, the field sample size shown in the CM Manual needs to be doubled.

Random Sampling

The quality management program special provision specification requires the contractor to test "randomly selected samples" for the following properties: 1) material finer than 200 sieve, 2) sieve analysis of fine and coarse aggregates, 3) open base No. 1 and No. 2, and 4) fractured particles. The use of random sampling practice is specified with the intention of eliminating bias in the sample selection process and, thus, increasing the representative state of samples. Greater reliability is assigned to test results from this process and the "strength of data" is improved for statistical purposes.

The standard method recommended for selecting random samples is ASTM Method D 3665, "Standard Practice for Random Sampling of Construction Materials." Random numbers may be selected by following the instructions or by using a calculator with a random number generator, excel spreadsheets, or other commonly accepted methods of selecting random numbers.


The selection of random sampling points should be done by the contractor QC personnel. In order to fully ensure the selection of samples is random, only those who need the information (i.e. QC personnel) should be notified. The operator(s) SHALL NOT be advised in advance as to when samples are to be taken. The effectiveness of process control sampling is completely reliant on unbiased sampling and testing. Collusion between the QC personnel and plant operator(s), in this regard, may be cause for DECERTIFICATION of the sampling technician. Details of the sample selection processes will be addressed under the specific discussion for sampling aggregate. Sampling from Production Selection of Random Sample

When the contractor is producing material for a specific project, aggregate samples shall be selected randomly for testing. For example, at the beginning of each day, the contractor shall specify the anticipated tonnage of base course to be produced for the day. The frequency of sampling will then be determined from the quality management special provisions. In this example, test gradation once per 1500 tons during initial production. The anticipated tonnage will be split into appropriate lots and a sample obtained randomly from each lot. An example for an anticipated production of 6000 tons of base course in a day would be:

Minimum number of samples per day = 2 [from special provisions]

Sample 1: from 0 to 3000 tons

Sample 2: from 3000 to 6000 tons The tonnage for obtaining each sample within the lot shall be determined by selecting two (2) random numbers as described in the Method for Statistical Sampling, pages C-10 and C-11.


The random numbers selected shall be multiplied by the tonnage lots selected for the day. These numbers shall then be added to the final tonnage of the previous lot to yield the approximate total tonnage when the samples are to be taken. Calculations for the above example are: +Final Tons Tonnage Tonnage Random Lot Size Previous = for Sample Range Number X Random No. Lot Sampling

1 0 - 3000 x 0.569 = 1707 + 0 = 1707 2 3000 - 6000 x 0.335 = 1005 + 3000 = 4005

This procedure is to be used for any number of samples selected randomly per day.

Example: ASTM D 3665 Random Sampling Method From Production At the beginning of the day, the contractor told the QC person that they would produce 6000 tons of BAD. The tests shall be taken from the conveyor belt. Determine the tonnage for sampling using the three-digit chart of numbers. Make sure to identify each random number with the designated line and column numbers. Frequency Daily Production (Tons) Number of Tests (per day) 0 - 3000 1 3000 - 6000 2

Sample No. 1st Random No.

2nd Random No.

Line No. Column No. Random No.

1 .842 .306 84 3 0.282

2 .259 .771 25 7 0.941

Sample

Tonnage Range

Random Number

Increments x

Random No.

+ Final Tons

Previous = Increment

Tonnage

for Sampling

1 1-3000 x 0.282 = 846 + 0 = 846

2 3000-6000

x 0.941 = 2823 + 3000 = 5823


Sampling from Roadbed The contractor quality control or quality assurance personnel shall obtain randomly selected samples of base course aggregate after the material has been placed out on the roadbed.

Selection of Random Samples for Gradation The tonnage points selected for sampling should be converted to correspond to stations on a project. This shall be accomplished by determining the station, which corresponds to the sample tonnage as close as is reasonably possible. Once the stationing is determined, the CM Manual shall be followed for determining the field sample size and for sampling from the roadbed. The sampling procedure in the CM Manual does not outline selection of sample lot locations by a mathematical random sample selection process. However, random sample selection should be used. For Example: It is determined the approximate station calculated tonnage is dumped on station 13+63. Next find the station offset for the actual sample location. The best solution to this is to set up an imaginary base line from existing field alignment stakes. Samples are typically taken from full depth base course (shoulder point to shoulder point). If the base course placement is too thick for one layer, more layers are used, and then samples are taken from each layer. Determine the width of aggregate based on layer placement. For this example, let us assume the width is 36 feet. The random number is 0.683. The offset from the base line (either side, but stay constant throughout the contract) is 36 X 0.683 = 25 feet rounded to nearest foot. Sampling shall take place after blading and shaping but prior to initiating compaction. The intent is to obtain samples as near to the final placement location of the material as possible so as to truly represent the aggregate placed. Sampling from roadbed windrows shall not be permitted, unless the subgrade is granular and with the prior approval of the engineer. Windrow samples are acceptable when it is not possible to differentiate the change in material between the BAD and the granular subgrade. Refer to the CM Manual for the procedure in sampling from windrows. One sampling method outlined in the CM Manual shall be adhered to throughout the work to facilitate data comparisons for the project. The contractor may make changes in sampling procedures if requested in writing and approved by the engineer.


Example: ASTM D 3665 Random Sampling Method From Roadbed

Identify three randomly selected increments on the roadbed below. The roadbed is 36 feet wide and 100 feet in length. All three of the randomly selected increments shall be plotted starting at station 100 + 00.

1. Use the ASTM D 3665 random number procedure to determine the three sampling

increments. Select the line and column numbers for each increment using the space

provided.

Sample No. 1st Random No. 2nd Random No. Line No. Column No. Random No.

1) .623 .885 62 8 0.157 2) .436 .344 43 3 0 .370

3) .921 .406 92 4 0.498 4) .179 .241 17 2 0.537 5) .541 .928 54 9 0.586 6) .365 .473 36 4 0.044 2. Determine the three sample increments by multiplying the appropriate random numbers

by the width and length of roadbed.

1st Increment

1) 36 ft x .157 = 5.7 ft 2) 100 ft x .370 = 37.0 ft 2nd Increment 3) 36 ft x .498 = 17.9 ft 4) 100 ft x .537 = 53.7 ft 3rd Increment 5) 36 ft x .586 = 21.1 ft 6) 100 ft x .044 = 4.4. ft 3. Plot the designated sample increments on the roadbed (offset vs. length).


STUDENT EXERCISE: Sampling From Production 1. At the beginning of the day, the contractor told the QC person that they would

place 6000 ton of BAD. The tests shall be taken from the conveyor belt. Determine the tonnage for sampling using the three-digit chart. Make sure to identify each random number with the designated line and column numbers. See B.1.5.1 – (2) Test gradation once per 3000 tons during initial production.

Frequency Daily Production (Tons) Number of Tests (per day) 0 – 3000 1 3000 - 6000 2


2nd Random

No.

Line No. Column No.

Random No.

1)

2)

Sample

Tonnage Range

Random Number

Increments x

Random No.

+ Final Tons

Previous = Increment

Tonnage

for Sampling

1)

2)


Station 100+00

36 ft

100 ft

STUDENT EXERCISE: Sampling from Roadbed

2. Identify three randomly selected increments on the roadbed below. The roadbed is 36 feet wide and 100 feet in length. All three of the randomly selected increments shall be plotted starting at station 100 +00.

Use the ASTM D 3665 random number procedure to determine the three sampling

increments. Select the line and column numbers for each increment using the space provided.


2nd Random

No.

Line No. Column No.

Random No.

1)

2)

3)

4)

5)

6)

Determine the three sample increments by multiplying the appropriate random numbers by the width and length to determine the sample increments. 1st Increment 1) station = 2) offset = 2nd increment 3) station = 4) offset = 3rd Increment 5) station = 6) offset = Plot the designated sample increments on the roadbed (offset vs. length).

(Baseline)


Random Sampling

A typical random numbers chart follows on the next two pages. Here is how you use it to select a random number. A. The area under the bell curve, the normal distribution curve is segmented into

1000 equal pieces. Each of these areas is represented by a 3 digit decimal number. The first number is .001, the 23rd number is .023, the 552nd number is .552, etc., and the last number is 1.000.

B. The chart is printed on two pages. You may combine them on one sheet for

convenience. It is a good practice to alternate pages. Use the page on the left then the page on the right. For the next number use the page on the right then the page on the left. (You select these numbers by simply pointing at them with your fingers or a pencil, with your eyes shut.

C. Point at a number. Write down the first number you’ve selected. Assume it is

0.272. This is the first number in the chart. Point again. Use the second half of the chart on the right. Write down the second

number you’ve selected. Assume it is 0.119. This is the last number in the chart. D. The rows of numbers that go up and down (vertical) are the line numbers. There

are 100 lines. Use the first two digits of our first number, 0.272 which are 2 and 7 or 27. This

identifies line 27. The rows of numbers that go across (horizontal) are the column numbers. There

are 10 columns. Note that the first column number is 0. Use the first digit of our second number, 0.119, which is 1. This identifies the

second column. Our random number is 0.235. The key thought to remember when using this method for statistical sampling is “It

takes two numbers to get one number.” E. There are nine exceptions to this procedure. Those exceptions are .001, .002,

.003, .004, .005, .006, .007, .008, and .009. (The number 0.000 is not in the chart). In the event that one of these numbers is selected in the pointing process, disregard that number and point at another.

Student Question: What happens if you select 1.000 in the pointing process? Answer:

Use line 100.


CHART OF RANDOM NUMBERS

0 1 2 3 4 5 6 7 8 9

1 0.272 0.519 0.098 0.459 1.000 0.554 0.250 0.246 0.736 0.432

2 0.994 0.978 0.693 0.593 0.690 0.028 0.831 0.319 0.073 0.268

3 0.039 0.449 0.737 0.501 0.960 0.254 0.239 0.474 0.031 0.720

4 0.144 0.695 0.339 0.621 0.128 0.032 0.413 0.617 0.764 0.257

5 0.312 0.138 0.670 0.894 0.682 0.061 0.832 0.765 0.226 0.745

6 0.871 0.838 0.595 0.576 0.096 0.581 0.245 0.786 0.412 0.867

7 0.783 0.874 0.795 0.430 0.265 0.059 0.260 0.563 0.632 0.394

8 0.358 0.424 0.684 0.074 0.109 0.345 0.618 0.176 0.352 0.748

9 0.494 0.839 0.337 0.325 0.699 0.083 0.043 0.809 0.981 0.499

10 0.642 0.514 0.297 0.869 0.744 0.824 0.524 0.656 0.608 0.408

11 0.485 0.240 0.292 0.335 0.088 0.589 0.127 0.396 0.401 0.407

12 0.728 0.819 0.557 0.050 0.152 0.816 0.404 0.079 0.703 0.493

13 0.029 0.262 0.558 0.159 0.767 0.175 0.979 0.521 0.781 0.843

14 0.918 0.348 0.311 0.232 0.797 0.921 0.995 0.225 0.397 0.356

15 0.641 0.013 0.780 0.478 0.529 0.520 0.093 0.426 0.323 0.504

16 0.208 0.468 0.045 0.798 0.065 0.315 0.318 0.742 0.597 0.080

17 0.346 0.429 0.537 0.469 0.697 0.124 0.541 0.525 0.281 0.962

18 0.900 0.206 0.539 0.308 0.480 0.293 0.448 0.010 0.836 0.233

19 0.228 0.369 0.513 0.762 0.952 0.856 0.574 0.158 0.689 0.579

20 0.746 0.170 0.974 0.306 0.145 0.139 0.417 0.195 0.338 0.901

21 0.363 0.103 0.931 0.389 0.199 0.488 0.915 0.067 0.878 0.640

22 0.663 0.942 0.278 0.785 0.638 0.002 0.989 0.462 0.927 0.186

23 0.545 0.185 0.054 0.198 0.717 0.247 0.913 0.975 0.555 0.559

24 0.360 0.349 0.569 0.910 0.420 0.492 0.947 0.115 0.884 0.452

25 0.789 0.815 0.464 0.484 0.020 0.007 0.547 0.941 0.365 0.261

26 0.279 0.609 0.086 0.852 0.890 0.108 0.076 0.089 0.662 0.607

27 0.680 0.235 0.706 0.827 0.572 0.769 0.310 0.036 0.329 0.477

28 0.078 0.444 0.178 0.651 0.423 0.672 0.517 0.660 0.657 0.972

29 0.676 0.830 0.531 0.888 0.305 0.421 0.307 0.502 0.112 0.808

30 0.861 0.899 0.643 0.771 0.037 0.241 0.582 0.578 0.634 0.077

31 0.111 0.364 0.970 0.669 0.548 0.687 0.639 0.510 0.105 0.549

32 0.289 0.857 0.948 0.980 0.132 0.094 0.298 0.870 0.309 0.441

33 0.961 0.893 0.392 0.377 0.864 0.472 0.009 0.946 0.766 0.287

34 0.637 0.986 0.753 0.566 0.213 0.807 0.017 0.460 0.515 0.630

35 0.834 0.121 0.255 0.453 0.376 0.583 0.422 0.371 0.399 0.366

36 0.284 0.490 0.402 0.151 0.044 0.436 0.747 0.694 0.136 0.585

37 0.038 0.814 0.594 0.911 0.324 0.322 0.895 0.411 0.160 0.367

38 0.351 0.283 0.027 0.220 0.685 0.527 0.943 0.556 0.853 0.612

39 0.143 0.384 0.645 0.479 0.489 0.052 0.187 0.990 0.912 0.750

40 0.512 0.056 0.018 0.122 0.303 0.803 0.553 0.729 0.205 0.925

41 0.296 0.705 0.156 0.616 0.534 0.168 0.564 0.866 0.739 0.850

42 0.451 0.536 0.768 0.518 0.481 0.880 0.835 0.734 0.427 0.847

43 0.837 0.405 0.591 0.370 0.104 0.848 0.004 0.414 0.354 0.707

44 0.724 0.153 0.841 0.829 0.470 0.391 0.388 0.163 0.817 0.790

45 0.665 0.825 0.671 0.623 0.770 0.400 0.068 0.440 0.019 0.944

46 0.573 0.716 0.266 0.456 0.434 0.467 0.603 0.169 0.721 0.779

47 0.332 0.702 0.300 0.570 0.945 0.968 0.649 0.097 0.118 0.242

48 0.755 0.951 0.937 0.550 0.879 0.162 0.791 0.810 0.625 0.674

49 0.439 0.491 0.855 0.446 0.773 0.542 0.416 0.350 0.957 0.419

50 0.700 0.877 0.442 0.286 0.526 0.071 0.154 0.988 0.333 0.626


CHART OF RANDOM NUMBERS Continued

0 1 2 3 4 5 6 7 8 9

51 0.523 0.613 0.752 0.733 0.528 0.072 0.820 0.929 0.777 0.461

52 0.905 0.182 0.567 0.249 0.227 0.229 0.604 0.304 0.217 0.142

53 0.373 0.120 0.602 0.793 0.692 0.863 0.954 0.873 0.107 0.675

54 0.057 0.953 0.041 0.090 0.223 0.508 0.806 0.438 0.203 0.586

55 0.967 0.040 0.708 0.271 0.189 0.342 0.740 0.801 0.985 0.263

56 0.917 0.715 0.758 0.005 0.666 0.599 0.934 0.100 0.987 0.085

57 0.131 0.646 0.659 0.047 0.051 0.562 0.435 0.731 0.362 0.317

58 0.326 0.605 0.443 0.601 0.386 0.560 0.378 0.172 0.445 0.636

59 0.299 0.106 0.237 0.732 0.796 0.476 0.099 0.804 0.735 0.950

60 0.101 0.055 0.776 0.686 0.171 0.533 0.936 0.095 0.982 0.211

61 0.267 0.598 0.754 0.658 0.274 0.215 0.177 0.218 0.330 0.628

62 0.471 0.102 0.454 0.568 0.963 0.357 0.882 0.507 0.157 0.580

63 0.535 0.881 0.014 0.966 0.958 0.190 0.180 0.759 0.433 0.355

64 0.277 0.458 0.295 0.196 0.772 0.148 0.466 0.291 0.688 0.046

65 0.719 0.167 0.181 0.653 0.328 0.070 0.015 0.155 0.631 0.063

66 0.385 0.858 0.713 0.883 0.916 0.084 0.561 0.999 0.379 0.668

67 0.862 0.928 0.822 0.812 0.977 0.395 0.788 0.920 0.673 0.698

68 0.486 0.938 0.757 0.749 0.991 0.219 0.264 0.932 0.898 0.006

69 0.091 0.872 0.959 0.922 0.727 0.811 0.075 0.374 0.133 0.730

70 0.146 0.482 0.930 0.611 0.179 0.011 0.248 0.886 0.344 0.926

71 0.709 0.184 0.390 0.409 0.191 0.117 0.860 0.135 0.406 0.134

72 0.996 0.896 0.760 0.347 0.053 0.372 0.193 0.756 0.565 0.914

73 0.971 0.859 0.147 0.114 0.418 0.889 0.792 0.064 0.652 0.288

74 0.202 0.538 0.026 0.949 0.696 0.008 0.846 0.259 0.415 0.425

75 0.212 0.321 0.778 0.940 0.496 0.231 0.664 0.903 0.473 0.909

76 0.207 0.799 0.487 0.022 0.813 0.891 0.500 0.368 0.725 0.437

77 0.818 0.503 0.906 0.224 0.904 0.892 0.455 0.343 0.924 0.197

78 0.701 0.984 0.174 0.141 0.704 0.908 0.048 0.828 0.997 0.058

79 0.035 0.380 0.001 0.381 0.251 0.497 0.214 0.794 0.552 0.588

80 0.221 0.200 0.587 0.353 0.584 0.270 0.885 0.110 0.956 0.711

81 0.647 0.403 0.530 0.738 0.280 0.457 0.650 0.276 0.661 0.973

82 0.667 0.722 0.327 0.723 0.410 0.635 0.012 0.907 0.316 0.677

83 0.644 0.590 0.021 0.269 0.042 0.062 0.387 0.183 0.964 0.544

84 0.302 0.123 0.116 0.282 0.851 0.256 0.648 0.845 0.782 0.993

85 0.633 0.933 0.331 0.546 0.842 0.016 0.236 0.164 0.923 0.976

86 0.060 0.681 0.683 0.775 0.624 0.955 0.126 0.655 0.919 0.113

87 0.165 0.532 0.431 0.341 0.092 0.244 0.222 0.336 0.034 0.216

88 0.875 0.691 0.383 0.382 0.596 0.301 0.275 0.188 0.868 0.805

89 0.726 0.902 0.252 0.130 0.238 0.398 0.763 0.463 0.615 0.140

90 0.273 0.393 0.285 0.161 0.619 0.865 0.551 0.030 0.571 0.258

91 0.253 0.821 0.600 0.023 0.606 0.849 0.610 0.577 0.082 0.774

92 0.340 0.654 0.173 0.495 0.498 0.992 0.192 0.506 0.751 0.129

93 0.194 0.290 0.592 0.983 0.509 0.998 0.522 0.627 0.741 0.540

94 0.166 0.450 0.210 0.204 0.840 0.826 0.833 0.516 0.965 0.375

95 0.712 0.314 0.033 0.823 0.629 0.939 0.887 0.066 0.743 0.081

96 0.622 0.800 0.710 0.575 0.678 0.465 0.802 0.969 0.150 0.784

97 0.313 0.294 0.897 0.718 0.614 0.876 0.025 0.049 0.620 0.125

98 0.137 0.087 0.003 0.483 0.201 0.209 0.320 0.935 0.447 0.787

99 0.243 0.679 0.844 0.069 0.024 0.543 0.714 0.234 0.505 0.428

100 0.361 0.359 0.230 0.761 0.334 0.149 0.511 0.475 0.854 0.119


This material explains in detail the WisDOT method for statistical sampling. This doesn’t replace the AASHTO Standards (i.e. T-2, etc.) or the ASTM standards (i.e. D-3665, etc.) that are referenced in those AASHTO Standards. You can get a copy of the AASHTO Standards at:

American Association of State Highway & Transportation Officials 444 N. Capitol Street, N.W.

Suite 249 Washington, DC 20001

(202) 624-5800 www.transportation.org

http://www.transportation.org/


Demonstration: When to get your Sample

Example Problem

o One test per 3000 tons

o Split into appropriate lots

Sample 1: 0 to 3000

Sample 2: 3000 to 6000


2nd Random No.


1

2

Sample Tonnage Range

Random Number

Increments X Random No.

+ Final Tons Previous= Increment

Tonnage For Sample

1 X = + 0 =

2 X = + =


Work Problem: When to get your sample

Example Problem

o One test per 3000 tons

o Split into appropriate lots

Sample 1: 0-3000

Sample 2: 3000-6000


2nd Random No.


1

2

Sample Tonnage Range

Random Number

Increments X Random No.

+ Final Tons Previous= Increment

Tonnage For Sample

1 X = + 0 =

2 X = + =


Stationing:

One Station = 100 feet

+, refers to the distance between stations.

Offset:

Distance from reference line.


Station 100+00

36 ft

100 ft

STUDENT EXERCISE: Sampling from Roadbed

2. Identify three randomly selected increments on the roadbed below. The roadbed is 36 feet wide and 100 feet in length. All three of the randomly selected increments shall be plotted starting at station 100 +00.

Use the ASTM D 3665 random number procedure to determine the three sampling

increments. Select the line and column numbers for each increment using the space provided.


2nd Random

No.

Line No. Column No.

Random No.

1) .298 .794

2) .608 .813

3) .338 .627

4) .073 .751

5) .925 .164

6) .352 .964

Determine the three sample increments by multiplying the appropriate random numbers by the width and length to determine the sample increments. 1st Increment 1) 100 X 2) 36 X 2nd increment 3) 100 X 4) 36 X 3rd Increment 5) 100 X 6) 36 X Plot the designated sample increments on the roadbed (offset vs. length).

(Baseline)

TOPIC D: Sampling Aggregates

TOPIC D: Sampling Aggregates D-1

Sampling of Aggregates

Aggregates are the main ingredient in most highway construction. They are used in all phases from base construction, pavement mixes, granular shoulders, granular surfacing, and erosion control. For aggregates to perform as intended, they must meet certain physical requirements such as proper gradation, durability to resist the effects of weathering, and resistance to abrasion loss. At this point, all the money and time which will be expended on the remaining activities of testing and evaluation may be lost or rendered useless by an improper sampling technique. In other words, if the samples taken are not representative of the total material, it is impossible to end up with meaningful test results. At the completion of this instruction, the technician must know how to obtain a proper sample. Without this knowledge, it is useless to proceed further into the areas of the test procedures. Test samples should represent the total amount of the material being produced or used. During production at the source, care must be taken to ensure the virgin material being processed is normal to the overall consistency of the available material. Clay pockets, boulders, or varying seams in a gravel pit, mine, or quarry may create short-term variations in the consistency of the product.

AGGREGATES “Are the main ingredient in most

highway construction.”

Importance of Sampling “If the samples taken are not representative of the total material, it is impossible to end up with meaningful test results. At the completion of this instruction, the technician must know how to obtain a proper sample. Without this knowledge, it is useless to proceed further into the areas of the test procedures.”


SAMPLING AGGREGATES


1. General. The minimum weight of the field sample depends on the nominal maximum particle size of the aggregate that is to be sampled. The weight of the field sample will always be greater than that portion required for testing and shall meet the requirements of Table 1.

TABLE 1 - SIZE OF SAMPLES

Nominal Maximum Size of Particles Passing Sieve

Minimum Weight of Field Samples

Kg Lb

Fine Aggregate

2.0 mm (No. 10) 5 10

4.75 mm (No. 4) 5 10

Coarse Aggregate

9.5 mm (3/8 in.) 5 10

12.55 mm (1/2 in.) 10 25

19.0 mm (3/4 in.) 15 35

25.0 mm (1 in.) 25 55

31.75 mm (1 ¼ in.) 25 55

37.5 mm (1 ½ in.) 30 70

50 mm (2 in.) 40 90

62.5 mm (2 ½ in.) 45 100

Larger than 2 ½ in. 115 250

Reference should be made to CMM 4-25-30, Materials Testing and Acceptance Guide, for specific sample sizes required for submittal to the Central Laboratory.

The sample should be reduced to the size needed for a specific test by using either a riffle splitter, quartering method or miniature stockpile method for damp fine aggregate only.

2. Definitions.

A. Field Sample. A composite of all increments sampled. B. The nominal maximum particle size as indicated by the appropriate

specification or description. If the specification or description does not indicate a nominal maximum size (for example a sieve size indication 90-100% passing), use the maximum size (that sieve indication 100% passing).

NOTE: Nominal maximum particle size definition for HMA = One size larger than the

first sieve to retain more than 10% and is distinct from other aggregates.


SAMPLING FROM A STOPPED CONVEYOR BELT After normal flow has been established, randomly obtain at least three approximately equal increments from the unit being sampled and combine them to form a field sample of the required size. Stop the conveyor belt while the sample increments are being obtained. Separate the increments at their ends and collect all the material, including the fines, and place in a container. The belt should be cleaned to the same standard as the return belt, no more. If the angle of the conveyor belt is such that the aggregates roll, place templates, with forms fitting the configuration of the conveyor belt, through the increments at their ends before collecting the material.

SAMPLING FROM A CONVEYOR BELT DISCHARGE Randomly select units to be sampled from production after normal flow has been established. Obtain at least three approximately equal increments from the unit being sampled and combine to form a field sample. Take each increment from the entire cross-section of the material as it is being discharged.

SAMPLING FROM STOCKPILES 1. Alternate 1. Obtain increment samples from

each quarter point of the working face of the stockpile, the working face being the face of the pile from which the aggregate is being removed. Obtain each quarter point sample by cutting deep into the face of the pile with an end loader or other similar power equipment. Dump each quarter point sample in a separate pile, level the pile, and take at least three shovels full to form one increment. The total sample will consist of three increments, one increment from each quarter point sample.


SAMPLING FROM STOCKPILES

2. Alternate 2. Obtain increments with a square-

nosed shovel from quarter points of the pile perimeter at both 1/3 and 2/3 levels of slope length from bottom to top. Increments shall be obtained by holding a protective barrier above the sampling location to prevent aggregate slide and discarding 254 - 305 mm (10 - 12 inches, of surface aggregate. Total sample = 8 increments.

. SAMPLING AFTER BEING PLACED ON ROADBED A visual inspection for uniformity of the area to be sampled should be made after the material has been mixed and bladed, mixed, shaped, watering and before compacting. Lack of uniformity should be corrected before proceeding with the sampling. Obtain at least three approximately equal increments, selected at random, from the unit being sampled. When the contract is in English units, a 100 foot unit should be selected to represent the area to be evaluated. If the above units cannot be selected, than another length may be selected and so noted in the project records. Take increments for the depth of the material under consideration, being careful not to contaminate the sample with any underlying material. When a shovel is used, it shall be squared-nosed. Care should be taken not to cause degradation of the aggregate during the sampling process. Care should also be taken to keep the sides as vertical as possible during the excavation


STUDENT EXERCISE:

Nominal Maximum Particle Size 1. Determine the appropriate aggregate sample size for a 3/4 in. (19.0 mm)

nominal maximum particle size to be utilized on a project when split samples are required by the provision.

a) 25 lb. (10 kg) b) 35 lb. (15 kg) c) 50 lb. (20 kg) d) 70 lb. (30 kg)

2. Determine the appropriate aggregate sample size for a 3/4 in. (19.0 mm)

nominal maximum particle size to be utilized on a project when split samples are not required by the provision.

a) 25 lb. (10 kg) b) 35 lb. (15 kg) c) 50 lb. (20 kg) d) 70 lb. (30 kg)


STUDENT EXERCISE - ANSWER

Nominal Maximum Particle Size


nominal maximum particle size to be utilized on a project when split samples are required by the provision.

a) 25 lb. (10 kg) b) 35 lb. (15 kg) c) 50 lb. (20 kg) d) 70 lb. (30 kg) – correct answer


nominal maximum particle size to be utilized on a project when split samples are not required by the provision.

a) 25 lb. (10 kg) b) 35 lb. (15 kg) – correct answer c) 50 lb. (20 kg) d) 70 lb. (30 kg)


Electronic Sample Form:

Reference form DT1499 found on this link:

http://wisconsindot.gov/Pages/global-footer/formdocs/default.aspx

http://wisconsindot.gov/Pages/global-footer/formdocs/default.aspx


CMM 8-60 Materials Testing and Acceptance - Aggregates

Table 1 Size of Samples

Nominal Maximum Size of Particles Passing Sieve Minimum Weight of Field Samples

Fine Aggregate kg lb.

No. 10 (2.0 mm) 5 10

No. 4 (4.75 mm) 5 10

Coarse Aggregate kg lb.

3/8 in. (9.5 mm) 5 10

1/2 in. (12.5 mm) 10 25

3/4 in. (19.0 mm) 15 35

1 in. (25.0 mm) 25 55

1 1/4 in. (31.75 mm) 25 55

1 1/2 in. (37.5 mm) 30 70

2 in. (50 mm) 40 90

2 1/2 in (62.5 mm) 45 100

Larger than 2 1/2 in 115 250

Refer to CMM 8-50, Materials Testing and Acceptance Guide, for specific sample sizes required for submittal to the central laboratory.

The sample should be reduced to the size needed for a specific test by using either a riffle splitter, quartering method or miniature stockpile method for damp fine aggregate only.

8-60.2.1.2 Definitions

Field sample A composite of all increments sampled.

Nominal maximum particle size The nominal maximum size as indicated by the appropriate specification or

description. If the specification or description does not indicate a nominal maximum size (for example a sieve size indicating 90-100% passing), use the maximum size (that sieve or size indicating 100% passing). Refer to Table 2.

December 2012 Page 2


CMM 8-60 Materials Testing and Acceptance - Aggregates

Table 2 Nominal maximum sizes based on the above definition taken from AASHTO

Material Nominal Maximum Size Remarks

Dense Graded Base, 3-inch 3-inch (75 mm)

Dense Graded Base, 1 ¼-inch 1 ¼ -inch (32 mm)

Dense Graded Base, ¾ -inch ¾ -inch (19 mm)

Open Graded Base 1-inch (25 mm)

Breaker run 6-inch (150 mm) When testing is required

Select Crushed 5-inch (125 mm) When testing is required

Concrete Aggregate – Size #2 1 ½- inch (37.5 mm)

Concrete Aggregate – Size #1 ¾ -inch (19 mm)

Concrete Aggregate – fine No. 4 (4.75 mm)

Granular Backfill (GBF), Trench Varies By strict definition, the 3-inch component would define the size. Use the largest size material in the sample irrespective of the specification to establish the nominal size. Example: If 100 % passes the 3-inch but there is 1-inch material in the R4, use 1- inch as the nominal maximum size.

Granular Backfill, Bedding 1-inch, may vary See note above for GBF-trench

Structural Backfill Up to 3-inch, may vary See note above for GBF-trench

December 2012 Page 3

TOPIC E: Sampling Asphaltic Mixtures from Truck Box E-0

Video: Hot Mix Asphalt-Truck Box Sampling

http://mediasite.uwplatt.edu/uwp/Play/6907f0169a664a748d28aae9a4adfdfe1d?catalog=fe890230-e467-4d26-ad5f-22b286b6d3d2

TOPIC E: Sampling Asphaltic Mixtures from Truck Box E-1

Truck Loading Procedures Proper truck loading procedure may help alleviate problems with segregation (typically consisting of larger-sized aggregate particles rolling down the side of the pile) of Hot-Mix Asphalt (HMA) during load-out. When loading HMA into a truck, a single dump will produce segregation of HMA material all around the inside edges of the truck box (refer to figure E-1, Single Dump Loading). Figure E-1. Single Dump Loading Figure E-2. Multiple Dumps

(Produces segregation all around the inside (Minimizes the segregated area within edges of the truck box) the truck box) Using multiple dumps reduces the surface area exposed to segregation, which, in turn, minimizes the segregation problem. The multiple dumps should be made as close as possible to the front and rear and the final dump should be placed in the center (refer to Figure E-2, Multiple Dumps). Sampling From the Truck Box Sampling from a truck box is the contractor’s responsibility. This sampling presents some safety hazards because it is necessary to climb atop the truck box and stand on the hot mixture while sampling. Special care should be exercised by the contractor (or his designated representative) as the sample is obtained to prevent falls or burns. Sample Device. The shovel or other approved sampling device shall be of such size and configuration that each increment of a sample can be obtained in one attempt without spilling or roll off. In order to satisfy this requirement with a flat bottom shovel, it is necessary to attach two to four inch vertical sides to the shovel. The total sample size is required to be enough material to meet the testing and retained requirements as set by the QMP. For guidance on amount of material needed see Topic Q (Procedure 4-15-52, page 4).

Sampling Asphaltic Mixtures from Truck Box

When the last batch has been dumped into the truck box, establish a reference point on the surface of the load, either at the high point if a conical shape exists or near the middle of the truck box if the surface shows no such conical shape. Then establish at least three incremental sample points about midway between the previously established point and the sides of the truck and equally spaced around the load (see sketch). At these sampling points, remove the upper two to three inches of mixture and then insert the sampling shovel or other approved device into the mixture to extract the sample increments and place increments in a sample container.

The total sample for a 4 mm mix shall weigh at least 70 lb.

X - Reference Point A - Sample Point B - Sample Point C - Sample Point

Figure E-3. Sampling Plan for a Truck Box

Figure E-4

Sampling Asphaltic Mixtures from Truck Box Page 1

Checklist for HMA Sampling Observe sample to be random by asking for documentation

Observe sample to be representative

Insure complete identifying/label information:

Paving Contractor Type of Asphalt Mixture

QV/QV-ret WisDOT Mix Design ID #

State Project ID # Percent Binder (%AC)

Date Daily Tonnage Sampled

Previous QC Sple # Current Gsb

Full name of sampler (and contact phone #)

Obtain a copy of mixture loadout ticket

Minimum sample size

Mixture NMAS Minimum Individual Sample Size

< 12.5mm (1/2") 35 lb. (4 x 35 = 140 lb. total)

19.0mm - 25.0mm (3/4" – 1") 450 lb. (4 x 50 = 200 lb. total)

> 37.5mm ( 1-1/2") 80 lb. (4 x 80 = 320 lb. total)

Separate trucks for QC & QV samples

Expedite samples to the Regional Lab (same/next day)

as there are specification requirements for completion

of testing.

Checklist for HMA Sampling Observe sample to be random by asking for documentation

Observe sample to be representative

Insure complete identifying/label information:

Paving Contractor Type of Asphalt Mixture

QV/QV-ret WisDOT Mix Design ID #

State Project ID # Percent Binder (%AC)

Date Daily Tonnage Sampled

Previous QC Sple # Current Gsb

Full name of sampler (and contact phone #)

Obtain a copy of mixture loadout ticket

Minimum sample size

Mixture NMAS Minimum Individual Sample Size

< 12.5mm (1/2") 35 lb. (4 x 35 = 140 lb. total)

19.0mm - 25.0mm (3/4" – 1") 450 lb. (4 x 50 = 200 lb. total)

> 37.5mm ( 1-1/2") 80 lb. (4 x 80 = 320 lb. total)

Separate trucks for QC & QV samples

Expedite samples to the Regional Lab (same/next day)

as there are specification requirements for completion

of testing.

Laboratory Exam

STUDENT DATE

HIGHWAY TECHNICIAN CERTIFICATION PROGRAM THE UNIVERSITY OF WISCONSIN - PLATTEVILLE

TRANSPORTATION MATERIALS

SAMPLING

QUALIFYING LABORATORY EXAM

AREA OF QUALIFICATION PASS/FAIL INSTRUCTOR

A. Sampling from a Conveyor Belt Discharge

B. Sampling after Being Placed on Roadbed

C. Sampling from a Conveyor Belt

D. Sampling from Stockpiles: Alternative 1 Alternative 2

E. Truck Box Sampling


Randomly select units to be sampled after steady flow has been established. Obtain at least three approximately equal increments and combine to form a

representative composite sample before splitting. Sample each increment from entire cross-section of material flow. Refer to Construction Materials Manual

Sampling after Being Placed on Roadbed

Area sample locations shall be selected by random number table on QC/QA projects.

Visually inspect the area to be sample for uniformity. Cavity walls shall be as vertical as possible. Care must be taken to avoid including any underlying material. Obtain at least three approximately equal increments sampled by a square-

point shovel. All increments shall be combined to form a representative composite sample

before splitting. Refer to Construction Materials Manual

Sampling from a Conveyor Belt

Randomly select units to be sampled after steady flow has been established. Stop conveyor belt while samples are being obtained. Obtain at least three approximately equal increments off the conveyor belt,

and combine to form a composite sample. Separate the increments at their ends; if the angle of the conveyor belt is

such that the aggregates roll, insert templates, which fit the configuration of conveyor belt for each sample location.

Collect cross-section of material on conveyor belt or between templates, and also brush fines into sample container.

All increments shall be combined to form a representative composite sample. Refer to Construction Materials Manual

Sampling from Stockpiles

Alternate 1

Obtain increments from each quarter point from which the aggregate is being extracted.

Obtain each quarter point sample by cutting deep into the face of the pile with a front-end loader or with similar power equipment.

Dump each quarter point sample in a separate pile, and level each pile. Obtain at least three approximately equal increments from each pile, and

sample by using a square-point shovel. Samples of all quarter points shall be combined to form a representative

composite sample. Alternate 2

Obtain increments with a scoop shovel from quarter points of pile perimeter at both 1/3 and 2/3 levels of slope length from top to bottom.

Sample shall be obtained by placing protective barrier above sampling location to prevent aggregate slide.

Remove 10” to 12” of surface aggregate before obtaining sample. Samples of all quarter points shall be combined to form a representative

composite sample. Refer to Construction Materials Manual

APPENDIX: QMP Award Nomination Form

The Quality Management Program Award recognizes outstanding certified highway materials technicians who have displayed exceptional leadership roles in developing quality materials used in highway construction projects.

These winners are chosen from contractors, consultants, and the Wisconsin Department of Transportation. It is this industry support and joint partnering that makes this program a success.

Some of the qualities attributed to the award winners include HTCP certification, HTCP promotion, development of cost savings, development of time savings, quality improvement, being a team player and possessing a positive attitude.

APPENDIX: Corrections APPENDIX: Course Evaluation

Quality Management Program Award Nomination

Application

*Application submitted by: Date:

Do you wish to remain anonymous?

(* Required for nomination)

Yes No

Please fax (608) 342-1982 or send completed application before November 1 of each year to Highway Technician Certification Program, University of Wisconsin-Platteville, 049 Ottensman Hall, 1 University Plaza, Platteville, WI 53818-3099.

*Application submitted by: Date:

Do you wish to remain anonymous?

(* Required for nomination)

Yes No

Please fax (608) 342-1982 or send completed application before November 1 of each year to Highway Technician Certification Program, University of Wisconsin-Platteville, 049 Ottensman Hall, 1 University Plaza, Platteville, WI 53818-3099.

This Outstanding Individual or Team is Nominated to Receive this Year’s “Quality Management Program Award”

Individual/Team: Employer:

Address: Work Address:

City/State/Zip: City/State/Zip:

Telephone: Telephone:

Fax :

List individual or team nominated:

Identify outstanding individual or team achievement(s) that exemplify this nomination for the “Quality Management Program Award

OOPS! Found an error?

Course Title:

Please describe the error and the page or topic where you found it:

We might have questions. How can we reach you?

Name:

Date: _______________________________

E-Mail:

Phone:

Note to Development Team: Send updates to [email protected], or call 608.342.1545, or mail to HTCP, 1 University Plaza, University of Wisconsin-Platteville, Platteville, WI 53818.

THANK YOU!

mailto:[email protected]

HIGHWAY TECHNICIAN

CERTIFICATION PROGRAM

(HTCP) EVALUATION

The HTCP would appreciate your thoughtful completion of all items on this evaluation. Your comments and constructive suggestions will be carefully studied and will serve as a valuable resource to improve our course presentations:

Course:

Date:

1. Overall rating of this program:

Outstanding Above

Average

Below Unacceptable

Average Average

How prepared the course material made you for the examinations.

5 4 3 2 1

Quality and quantity of the course materials? 5 4 3 2 1

How prepared the course has made you for the role you will be performing in your job.

5 4 3 2 1

Course registration process. 5 4 3 2 1

Please rate the relevancy of the technology used during the course.

5 4 3 2 1

Please rate the responsiveness of the HTCP administrative staff.

5 4 3 2 1

Please provide specific detail for ratings that are below average or unacceptable:

2. Facilities/Lab Ratings:

Outstanding Above

Average Below

Unacceptable Average Average

Seating/size of the classroom 5 4 3 2 1

Parking at the facility. 5 4 3 2 1

Size and layout of the lab. 5 4 3 2 1

Condition of the lab equipment. 5 4 3 2 1

Condition of the lab material. (Aggregate, concrete, asphalt, etc...)

5 4 3 2 1


3. Instructor Ratings:

Outstanding Above

Average Below

Unacceptable Average Average

Instructors knowledge of the course materials:

5 4 3 2 1

Instructor organization: 5 4 3 2 1

Student/Instructor interactions: 5 4 3 2 1

Feedback provided by the instructors: 5 4 3 2 1

Encouraged class discussion: 5 4 3 2 1

Please rate the ability of the instructor to stay within the agenda's timelines:

5 4 3 2 1

Referred to, and utilized course materials: 5 4 3 2 1

How would you rate the instructor’s overall teaching effectiveness?

5 4 3 2 1


4. What did you like most about the course?

5. What did you like least about the course?

6. Please comment about overall course quality and length:

:

transportation materials sampling (tms) · lab exam laboratory exam ... the weight per unit volume...

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