Portland Cement Concrete Technician II

Portland Cement Concrete Technician II

HIGHWAY TECHNICIAN CERTIFICATION PROGRAM University of Wisconsin-Platteville 049 Ottensman Hall 1 University Plaza Platteville, WI 53818-3099 Office Phone; 608-342-1545 Fax: 608-342-1982

PREFACE

The WisDOT certified Portland Cement Concrete Technician II course manual was prepared and developed by the Highway Technician Certification Program (HTCP) staff, the HTCP instructors, and other contributors from the Wisconsin Department of Transportation (WisDOT) and the highway industry. The information contained in this course manual is intended to be used to train WisDOT Quality Management Program (QMP) Portland cement concrete technicians. The intent of this manual is to illustrate the related AASHTO/ASTM test standards and discuss the ACI Portland cement mix design process control adjustments. It is the responsibility of the Portland Cement Concrete Technician-II to follow all current WisDOT specification parameters and procedures in accordance when conducting work assignments for the Wisconsin Department of Transportation.

The WisDOT certified Portland Cement Concrete Technician II course manual was developed in conjunction with these valuable resources:

(1) Wisconsin Department of Transportation Construction and Materials Manual,

Chapter 8, Section 35 QMP – Concrete

(2) Design and Control of Concrete Mixtures, Portland Cement Association, 15th Edition

ACKNOWLEDGMENTS

The following HTCP Portland Cement Concrete Technical committee members have been instrumental contributors to the contents of this course manual:

Jim Parry - WisDOT Bureau of Technical Services Ron Treuer - Consultant Kevin McMullen - Wisconsin Concrete Pavement Association Tom Braun - Lunda Construction David Kopacz - Federal Highway Administration Tim Bolwerk - OMNNI Associates Terry Treutel - WisDOT Bureau of Technical Services Ray Spellman - UW-Platteville Richard Sorensen – WisDOT QMP Engineer

WisDOT Technical Assistance Hotline Representative Russell Frank, WisDOT Bureau of Technical Services- (608) 246-7942

We also thank the Portland Cement Association for photos & figures and

Howard “Buck” Barker for text edits.

TABLE of CONTENTS TOPIC A WisDOT Aggregate Correction Factor Procedure

TOPIC B AASHTO T 85 Test Method for Density, Relative Density (Specific Gravity), and Absorption of Coarse Aggregate

TOPIC C AASHTO T 84 Test Method for Density, Relative Density (Specific Gravity), and Absorption of Fine Aggregate

TOPIC D AASHTO T 19 Bulk Density (Unit Weight) and Void in Aggregate

TOPIC E Cementitious Materials – Portland Type I, II and III Cements, SCM – Class C Fly Ash & Slag

TOPIC F Admixtures – Air-Entraining, Water Reducers including Superplasticizers, Non Chloride Accelerators, Retarders, and Troubleshooting Guide for Solving Air Content Problems

TOPIC G Combined Aggregate Gradation

TOPIC H Theory of ACI Portland Cement Concrete Mix Design

TOPIC I Hot/Cold Weather Concreting

TOPIC J Statistical Analysis of Compression Tests – Percent Within Limits (PWL) Calculation

TOPIC K Review Latest Quality Management Program Specification

TOPIC L Record Keeping – Control Charts

TOPIC M Worksheets

TOPIC N Curing Concrete

TOPIC O Concrete Depth Probing

TOPIC P Trial Batching TOPIC Q Data Entry

TOPIC R AppendixMix Design-Research-Software, QMP Award, Corrections, Course Evaluation

Day 1

PORTLAND CEMENT CONCRETE TECHNICIAN - LEVEL II Syllabus

8:00 - 8:15 Registrations, Introductions, Course Objectives and Course Syllabus

8:15 - 9:15 WisDOT Aggregate Correction Factor Procedure

9:15 - 10:15 AASHTO T 85 Test Method for Density, Relative Density (Specific Gravity), and Absorption of Coarse Aggregate

10:15 - 10:30 Break 10:30 - 11:00 AASHTO T 84 Test Method for Density, Relative Density (Specific Gravity),

and Absorption of Coarse Aggregate

11:00 - 11:15 AASHTO T19 Bulk Density (Unit Weight) and Voids in Aggregate

11:15 - 11:45 Portland Type I, II, & III Cements, SCM-Class C Fly Ash & Slag

11:45 - 12:45 Lunch Break

12:45 - 1:15 Admixtures – Air-Entraining, Water Reducers including Superplasticizers, Non-chloride Accelerator, Retarder, and Troubleshooting Guide for Solving Air Content Problems

1:15 - 2:45 Combined Aggregate Gradation

2:45 - 3:00 Break

3:00 - 4:15 Theory of ACI Portland Cement Concrete Mix Design

4:15 - 5:00 Hot/Cold Weather Concreting

Day 2

8:00 - 8:30 Statistical Analysis of Compression Tests - Percent Within Limits (PWL)

8:30 - 10:30 Review latest Quality Management Program specification

10:30 - 10:45 Break

10:45 - 11:45 Continue Review latest Quality Management Program specification

11:45 - 12:45 Lunch Break

12:45 - 2:30 Continue Review latest Quality Management Program specification

2:30 - 2:45 Break

2:45 - 4:00 Record keeping - Control Charts

4:00 - 4:30 Project Worksheets - Data Entry

4:30 - 5:00 Curing/Concrete Depth Probing

Day 3

8:00 - 12:00 Written Examination

Adjourn

Course Overview i

Introduction The Highway Technician Certification Program (HTCP) welcomes you to the Certified Portland Cement Concrete II course. This course requires 16 hours of classroom/laboratory attendance. The course content will cover WisDOT aggregate correction factor. Coarse and fine relative density (specific gravity) and absorption, dry rodded bulk density (unit weight) by rodding, cementitious materials, admixtures, combined aggregate gradation, proportioning of concrete mixtures, hot/cold weather concreting, statistical analysis, record keeping, latest Quality Management Program Specifications, and curing/concrete depth probing.

Course Prerequisites

Portland Cement Concrete Technician Level I, PCCTEC-I

A person may earn 1.6 continuing education units (CEU’s) upon successful completion of this course.

Certification Requirements

The written examination will be limited to a maximum duration of four (4) hours. The written examination will be “open book and open notes” and will consist of true/false, multiple-choice, and essay questions. A student will be required to obtain a passing score of 70 percent to be certified as a Certified Portland Cement Concrete Technician II.

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.

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 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.

Highway Technician Certification Program Goal

The principal 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).

Course Overview (Cont.) ii

Introduction of Course Participants At this time, you will be asked to introduce yourself, company name, years of service to the Portland cement concrete 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 compressive Strength Tester I course. Please list and identify topics below:

Responsibilities of a Certified Portland Cement Concrete Technician II

The duties and responsibilities of a Certified Portland Cement Concrete Technician II are:

Know how to trouble-shoot and proportion Portland cement concrete mixtures

Know how the WisDOT aggregate correction factor affects air pressure test results

Know the importance of proportioning concrete mixture by mass-volume relationships

Know the types of cementitious materials and be able to calculate water/cementitious ratio

Know the types of admixtures available and be able to identify their specific uses

Know the detrimental effects related to hot/cold weather concreting

Know the importance of proper curing methods and relationship to quality concrete mixtures

Know the specific procedures for obtaining concrete pavement depth checks

Know the safety, handling and storage requirements for the equipment

Know which project personnel to contact to obtain specification requirements, evaluate the tests

results in relation to these specifications, and report results to the appropriate persons

Be able to maintain records in an organized manner, and to document sampling and testing

performed and actions taken as a result of sampling and testing required by specification

TOPIC A: WisDOT Aggregate Correction Factor A-1

TOPIC A: WisDOT Aggregate Correction Factor A-2 AASHTO T 152, Section 6 – Determination of the Aggregate Correction Factor The Standard Specifications require that the percentage of entrained air in concrete mixes shall be determined in accordance with the requirements of AASHTO T 152. The aggregate correction factor may be obtained by mixing representative samples of the aggregates mixed in the proportions as batched. Fill the measured bowl one-fourth full of water. Add the mixed aggregate a small amount at a time until all of the aggregate is inundated (overflowed). Add each scoopful in a manner that will entrap as little air as possible and remove accumulations of foam promptly. Tap the sides of the bowl and lightly rod the upper inch of the aggregate about ten times and stir after each addition of aggregate to eliminate entrapped air. When all of the aggregate has been placed in the bowl and inundated for a period of time approximately equal to the time between introduction of the water into the mixer and the time of performing the test for air content, strike-off all foam and excess water and thoroughly clean the flanges of both the bowl and conical cover so that when the cover is clamped in place a pressure-tight seal will be obtained. Complete the test as described in AASHTO T 152 with the added step of removing 5.0%, by volume, of the liquid in the meter. Use calibration tubes to remove the liquid. Note 3 of AASHTO T 152, Section 6 (Determination of Aggregate Correction Factor) reads as follows: The aggregate correction factor will vary with different aggregates. It can be determined only by test, since apparently it is not directly related to absorption of the particles. The test can be easily made and must not be ignored. Ordinarily the factor will remain reasonably constant for given aggregates, but an occasional check test is recommended. In order to prevent gross errors in field determination of the aggregate correction factor for correction of total air content of freshly-mixed concrete obtained by the pressure methods, as well as eliminating the need to make this determination in the field in many cases, the laboratory will show the value on the Mix Design for Portland Cement Concrete report for each proportion & each source of aggregates. These tests are also reported electronically on the Materials Reporting System (MRS). Contact the District Materials Section for the applicable test for your source. If the WisDOT Truax Materials Laboratory determines aggregate correction factors of concrete aggregates, they will use proportions of 40% fine aggregate (FA) and 60% coarse aggregate (CA). They proportion the coarse aggregates to be 40% No. 1 CA and 60% No. 2 CA. If proportions used in the field do not vary by more than 10%, the value shown on the aggregate quality report may be used without field test.

Formula: As = A1 – G As = air content of sample tested (reported), percent A1 = apparent air content of the sample tested (meter reading), percent G = aggregate correction factor (from mix designer), percent

TOPIC B: AASHTO T 85 Relative Density (Specific Gravity) B-1 And Absorption of Coarse Aggregate

TOPIC B: AASHTO T 85 Relative Density (Specific Gravity) B-2 And Absorption of Coarse Aggregate “The relative density (specific gravity) of an aggregate is the ratio of its density (not including volume of voids between particles) to the density of an equal absolute volume of water (water displaced by immersion).” Relative Density (Specific Gravity)

Normal relative densities (specific gravities) of an aggregate usually range from 2.40 to 2.90 in the State of Wisconsin. The relative density (specific gravity) of water is one, 1.00 at 4ºC. For instance you may better understand this concept if you know the relative density (specific gravity) of an aggregate, let’s say, 2.65, this actually means the density of the aggregate is 2.65 times more than the density of the water (if at 4ºC). However, there is no correlation between the relative density (specific gravity) of an aggregate and its quality. Aggregate quality is measured and determined by the Los Angeles abrasion test (ASTM C 131), sodium soundness test (ASTM C 88) and other ASTM C 33 specified tests. However, some porous aggregates not meeting sodium soundness test specifications have been known to have lower specific gravities. Two test methods for determining specific gravities of coarse and fine aggregates are: 1) AASHTO T 85 - Test Method for Density, Relative Density (Specific Gravity), and Absorption of Coarse Aggregates and 2) AASHTO T 84 - Test Method for Density, Relative Density (Specific Gravity), and Absorption of Fine Aggregates. Both of these test methods will be discussed later in this manual. Two aggregate conditions are used to express relative densities (specific gravities) to proportion Portland cement concrete mixtures: 1) Relative density (specific gravity) in an oven dry (OD) condition and 2) Relative density (specific gravity) in a saturated-surface-dry (SSD) condition. Oven dry aggregates do not contain any absorbed or free water. These aggregates are dried to a constant mass in an oven. Saturated-surface-dry aggregates are aggregates in which the pores in each aggregate particle are filled with water and no excess water is on the particle surface2.

Two test methods for determining relative densities of coarse and fine aggregates are: 1. AASHTO T 85 – Test Method for Density, Relative Density (Specific Gravity), and

Absorption of Coarse Aggregate 2. AASHTO T 84 – Test Method for Density, Relative Density (Specific Gravity), and

Absorption of Fine Aggregates

Two aggregate conditions are used to express density and relative density (specific gravity): 1. Oven-dry (OD) 2. Saturated-surface-dry (SSD)

TOPIC B: AASHTO T 85 Relative Density (Specific Gravity) B-3 And Absorption of Coarse Aggregate Absorption The absorption and surface moisture of the aggregates should be determined so that the net water content of the concrete can be calculated to control and correct batch weights. The internal structure of the aggregate particle is made up of solid matter and voids that may or may not contain water. There are four moisture conditions of an aggregate: 1) Oven dry (OD) – dried by heating and fully absorbent. 2) Air dry – dry at the particle surface but containing some interior moisture, thus somewhat

absorbent.

3) Saturated-surface-dry (SSD) – permeable pores are filled with water, but without free water on the surface of the particles and therefore neither absorbs water from nor contributes water to the concrete mixture.

4) Damp or wet-containing an excess of moisture on the surface (also called free water). The amount of water batched or added at the job site must be adjusted for the moisture condition of the aggregate to meet the designed water requirement. If the water content in the aggregates varies from batch to batch, the properties of the concrete will vary. The unknown amount of water added or shorted from the concrete mixture will affect the compressive strength, workability, and other important properties of the concrete.

Significance and Use Bulk relative density (specific gravity) is the characteristic generally used for calculation of the volume occupied by the aggregate in various mixtures containing aggregate including Portland cement concrete, hot mix asphalt and other mixtures that are proportioned or analyzed on an absolute volume basis. Bulk relative density (specific gravity) determined on the saturated surface-dry basis is used if the aggregate is wet, that is, if its absorption has been satisfied. Conversely, the bulk relative density (specific gravity) determined on the oven-dry basis is used for computations when the aggregate is dry or assumed to be dry.

1

2 3 4

1 Obtain representative test sample by splitting to mass based on nominal maximum particle size.

2 Reject all material passing a 4.75-mm (No. 4) by dry sieving.

3 Thoroughly wash the sample over the 4.75-mm (No. 4) sieve. Using a 75-mm (No. 200) sieve

to wash the sample is not necessary.

4 Dry (230 ± 9ºF) the test sample to a constant mass and cool at room temperature to the hand

touch. If the specific gravity values are to be used for proportioning concrete mixtures, the initial drying my be performed at the end of the test if the particles have been kept continuously wet.

Nominal Max. Size, in (mm)

Min. Mass of Test Sample, lb (kg)

1/2 (12.5) or less 4.4 (2)

3/4 (19.0) 6.6 (3)

1 (25.0) 8.8 (4)

1½ (38.1) 11 (5)

2 (50) 18 (8)

2½ (63) 26 (12)

3 (75) 40 (18)

3½ (90) 55 (25)

AASHTO T 85 (WisDOT Modified) Test Method for Relative Density (Specific Gravity) & Absorption of Coarse Aggregate

B-4

Laboratory Equipment

1. Scale or balance 7. Electric/Gas hot plate 2. Weigh pans 8. Metal spoon 3. Drying towel 9. No. 4 Sieve 4. Wire mesh basket 10. No. 200 & 16 sieves 5. Suspend Apparatus 11. Potable water 6. Water bath with overflow

5 6 7

5 Immerse the aggregate in water at room temperature for a period of 15 to 19 hours.

6 Remove the test sample from the water and roll it in a large absorbent cloth until all visible films

of water are removed. Be careful to avoid evaporation of water from aggregate pores.

7 Determine the mass the test sample in the saturated surface-dry condition. Record this and all subsequent masses to the nearest 1.0 g or 0.1% of the sample mass, whichever is greater.

8 9

8 After determining the mass, immediately place the saturated-surface-dry test sample in the

sample container and determine its mass in water at 23 ± 1.7o C (74.3 ± 3o F), having a density of 997 ± 2 kg/m3. Take care to remove all entrapped air before determining the mass by shaking the container while immersed.

Note: The container should be immersed to a depth sufficient to cover it and the test sample during mass determination. Wire suspending the container should be of the smallest practical size to minimize any possible effects of a variable immersed length.

9 Dry (230 ± 9ºF) the test sample to constant mass, cool in air at room temperature to the hand touch and determine the mass of the test sample.

Notes:

B-5 AASHTO T 85 (WisDOT Modified)

Test Method for Relative Density (Specific Gravity) & Absorption of Coarse Aggregate

Reference: ASTM C 127 Test Method for Relative density (specific gravity) and Absorption of Coarse Aggregate

Coarse Aggregate Relative Density (Specific Gravity) AASHTO T 85 Project Number: Sample Number:

Nominal Maximum Particle Size:


TEST #1 TEST #2 TEST #3 TEST #4

B = Wt. Of SSD

1. Wt. Of Sample + Basket in Water 2. Wt. Of Basket in Water C = Wt. Of Sample in Water (1-2)

3. Wt. Of Pan + Oven Dry Agg. 4. Wt. Of Pan A = Wt. Of Oven Dry Agg. (3-4)

B – C (Saturated Volume of Agg) A – C (Dry Volume of Agg) B – A (Absorbed Water)

Bulk Dry S.G. = A/ (B – C) Bulk SSD S.G. = B / (B – C) Apparent S.G. = A / (A – C) Absorption % = [(B – A) / A] x 100

Summary of Data:

Average Bulk Dry S.G. (Gsb) Average Bulk SSD S.G. Average Apparent S.G. (Gsa) Average Absorption, %

Coarse Aggregate Relative Density (Specific Gravity) AASHTO T 85 Project Number: Sample Number:




B = Wt. Of SSD

1. Wt. Of Sample + Basket in Water 2. Wt. Of Basket in Water C = Wt. Of Sample in Water (1-2)

3. Wt. Of Pan + Oven Dry Agg. 4. Wt. Of Pan A = Wt. Of Oven Dry Agg. (3-4)


Bulk Dry S.G. = A/ (B – C) Bulk SSD S.G. = B / (B – C) Apparent S.G. = A/ (A – C) Absorption % = [(B – A) /A] x 100

Summary of Data:


TOPIC C: AASHTO T 84 Relative Density (Specific Gravity) C-1 And Absorption of Fine Aggregate

Significance and Use Bulk relative density (specific gravity) is the characteristic generally used for calculation of the volume occupied by the aggregate in various mixtures containing aggregate including Portland cement concrete, hot mix asphalt and other mixtures that are proportioned or analyzed on an absolute volume basis. Bulk relative density (specific gravity) determined on the saturated surface-dry basis is used if the aggregate is wet, that is, if its absorption has been satisfied. Conversely, the bulk relative density (specific gravity) determined on the oven-dry basis is used for computations when the aggregate is dry or assumed to be dry. 1

1 Obtain approximately 1 kg of the fine aggregate from the sample using the applicable

sampling/splitting procedures.

2 3 4

2 Dry test sample in a suitable pan to a constant mass at a temperature of 110 ± 5o C

(230 ± 9 o F) and cool sample to the hand touch.

3 Cover the test sample with potable water and soak for 15-19 hours.

4 Remove excess water with care to avoid loss of fines, spread the sample on a flat nonabsorbent

surface exposed to a low-speed fan and stir frequently.

AASHTO T 84 (WisDOT Modified) Test Method for Relative Density (Specific Gravity) & Absorption of Fine Aggregate

C-2

Laboratory Equipment

1. Scale or balance 6. Funnel 2. Weigh pans 7. Oven 3. Pycnometer 8. No. 4 Sieve 4. Metal Cone 9. No. 200 & 16 wash sieve 5. Tamper 10. Potable water

5 6 7

5 Place the metal tamping mold on the nonabsorbent smooth surface with the large diameter

down. Place the portion of the partially dried fine aggregate loosely in the mold by filling it to overflowing and heaping.

6 Permit the tamper to fall freely into the mold of fine aggregate with 25 light drops. Each drop

should start approximately 5 mm (0.2 in) from the surface. 7 Remove loose sand from the base and lift the mold vertically. If surface moisture is still present,

the fine aggregate will maintain molded shape. 8 9 10

8 Continue steps 6 and 7 until the fine aggregate slumps slightly. This indicates that the sand has

reached a surface-dry condition. Note: Some angular fine aggregate or material with a high proportion of fines may not slump in the cone test upon reaching a surface-dry condition. Special procedures exist for this situation. Special procedures also exist for single-size material that slumps when wet.

8.5 Take a moisture sample for moisture content as a double check of the absorption percentage.

9 Determine the mass of the dry pycnometer and partially fill with 23 ± 1.7o C (73.4 ± 3 o F) water.

Immediately introduce into the pycnometer approximately 500 g of saturated surface-dry fine aggregate prepared from step 8.


C-2

C-3

10 Fill the pycnometer with additional water just below the calibration mark.

11 12 13

10. Fill the pycnometer with additional water to just below the calibration mark.

11 Roll, invert, and agitate the pycnometer to eliminate all air bubbles. It normally takes 15 to 20

minutes to eliminate the air bubbles.

12 Add 23 ± 1.7o C (73.4 ± 3 o F) potable water to adjust the water level to the calibration mark.

13 Determine the total mass of the pycnometer, specimen, and water. 14 15 14 Determine the dry mass of the sand in the pycnometer. Remove the contents from the

pycnometer into a pan.

15 Dry pycnometer contents to a constant mass at a temperature of 110 ± 5o C (230 ± 9 o F). Cool

in room temperature and determine the mass to nearest 0.1 g.


C-4

Reference: ASTM C 128 Test Method for Relative density (specific gravity) and Absorption of Fine Aggregate

Place the pycnometer on the scale

Fine Aggregate Relative Density (Specific Gravity) AASHTO T 84 Project Number: Sample Number:


Flask Number

1. Wt. Of Flask + SSD + Water 2. Wt. Of Flask + Water C = Wt. Of SSD in Water (1 – 2)

3. Wt. Of Flask + SSD 4. Wt. Of Flask B = Wt. Of SSD (3 – 4)

5. Wt. Of Pan + Over Dry Agg. 6. Wt. Of Pan A = Wt. Of Oven Dry Agg. (5 – 6)


Bulk Dry S.G. = A / (B – C) Bulk SSD S.G. = B / (B – C) Apparent S.G. = A / (A – C) Absorption % = [(B – A) / A] x 100

With or Without #200


TOPIC D: AASHTO T 19 Bulk Density (Unit Weight) D-1 And Voids In Aggregate


The bulk density (traditionally “unit weight”) of an aggregate is the mass per unit volume in a compacted or loose condition (including voids between particles). This test method only applies to aggregates smaller than a 5 in. (125 mm) nominal maximum size. Notes, Figures, and Tables:

Bulk Density

Of Coarse Aggregates By Dry-Rodding

(Unit Weight) - AASHTO T 19

Purpose: To obtain the approximate the maximum dry density of coarse aggregate for concrete mixture. Theory: The widely used ACI -211 method of concrete design uses the dry-rodded density of coarse aggregates. The most economical concrete mix with the best physical properties contains the maximum amount of coarse aggregate particles. Therefore, the coarse aggregate is placed in a container of known volume and then rodded and worked to get as many pieces as possible into the container; the resulting density is measured. If the concrete mix can be designed using this amount of coarse aggregate, the amounts of sand, cement, and water required to fill the spaces between the coarse aggregate particles will be a minimum. However, workability, finishability, and pumpability considerations still need to be made.


Apparatus: Balance readable to 0.1% of the sample mass Tamping rod (5/8 in. Slump Test rod) Measure of known volume (minimum) as follows:

Nominal Maximum Aggregate Size

in. (mm)

Minimum Capacity of Measure

ft3 (m3)

Minimum Capacity of Measure

(L)

½ (12.5) 1/10 (.0028) 2.8

1 (25.0) 1/3 (.0093) 9.3

1½ (37.5) ½ (.014) 14

Procedure: 1. Calibrate the volume of the measure using AASHTO T 19 procedures. 2. Document the mass of the measure. 3. Obtain a sample of clean, dry mixed aggregate. If more than one coarse

aggregate size is used; blend the sizes in the proportions planned in the mix. 4. Fill the container one-third full, level the surface, and rod 25 times without forcibly

striking the bottom of the measure. 5. Fill the measure two-thirds full, level, and vigorously rod the layer 25 times, but not

more than needed to penetrate to the previous layer. 6. Fill the container, level, and rod 25 times as before. 7. Level the surface using your fingers or a straightedge balancing slight aggregate

protrusions with voids in the surface below the top of the measure. 8. Obtain the mass of the measure and aggregate. Document Results: Calibrated Volume of Measure cu ft (m3) Mass of Measure & Aggregate lb (kg) Mass of Measure lb (kg) Net Mass of Aggregate lb (kg) Calculations: Bulk Density = Net Mass of aggregate = lb/cu ft OR (kg/m3) Volume of Measure Bulk Density in SSD condition = Dry-rodded Density X [1+ (% absorption)] 100

Student Problem: The coarse dry-rodded density test has been conducted using 1½ in. (37.5 mm) maximum aggregate size. The mass of the measure is 21.02 lb (9.53 kg). The mass of the measure containing aggregate is 68.08 lb (30.84 kg). The absorption of 1½ in. (37.5 mm) aggregate is 1.5 percent. a) Determine the specified minimum size capacity measure that can be used. b) Note the calibrated volume of the measure as calibrated (given). 0.498 cu ft c) Determine the net mass of aggregate. d) Calculate the dry-rodded density of the aggregate. e) Calculate the saturated-surface-dry density.

Student Problem: Answer The coarse dry-rodded density test has been conducted using 1½ in. (37.5 mm) maximum aggregate size. The mass of the measure is 21.02 lb (9.53 kg). The mass of the measure containing aggregate is 68.08 lb (30.84 kg). The absorption of 1½ in. (37.5 mm) aggregate is 1.5 percent. a) Determine the specified minimum size capacity measure that can be used. 1/2 cu ft b) Note the calibrated volume of the measure as calibrated (given). 0.498 cu ft c) Determine the net mass of aggregate.

Mass of Measure & Aggregate = 68.08 lb (30.88 kg) Mass of Measure = 21.02 lb (9.53 kg) Net mass of aggregate = 47.06 lb (21.35 kg)

d) Calculate the dry-rodded density of the aggregate. Dry-rodded Density = 47.06 lb = 94.5 lb/cu ft 0.498 cu ft e) Calculate the saturated-surface-dry density.

Saturated-surface-dry Density = 94.5 lb/cu ft x [1 + ( 1.5% )] = 95.9 lb/cu ft

100

TOPIC E: Cementitious Materials, Including: E-1 Type I, II and III Cements, Type C Fly Ash, & Slag Cement


Portland Cement

Notes, Figures, and Tables:

Cementitious materials are substances that alone have hydraulic cementing properties (set and harden in the presence of water).

Portland cements are hydraulic cements composed primarily of hydraulic calcium.

Cementitious Materials Include: Portland Cement

Class C Fly Ash

Natural cement

Ground granulated blast-furnace slag (slag or slag cement)

Hydraulic hydrated lime

Types of Portland Cement

Different types of cement are manufactured to meet various normal physical and chemical requirements for specific purposes (See page 36, Design & Control):

Type I Normal

Type II Moderate sulfate resistance

Type III High early strength

Type IV Low heat of hydration

Type V High sulfate resistance

NOTE: “A” designation denotes air-entrainment added to cement.


Type I – Portland Cement General Purpose cement suitable for all uses May be used when areas are not exposed to:

Sulfate attack from soil or water Objectionable temperature rise due to heat generated by hydration

Its uses include:

Highway pavements Floors Reinforced concrete buildings Bridges Railway structures Tanks and reservoirs Pipes Masonry units Other precast concrete products

Type II – Portland Cement

Used where moderate sulfate attack is important. During hydration, generates less heat than Type I. Used in structures with considerable mass – heavy abutments/retaining walls Will reduce temperature rise when placed in warm water. Note: It should be noted Type II Portland Cement is only low heat when optional chemical requirements for C3S + C3A 58% is met. This

type of cement may have to be special ordered. Otherwise, Type II cement may have the same heat as Type I.



Type III – Portland Cement

Provide high strengths at an early period (usually a week or less)

Chemically and physically similar to Type I cement particles that have been ground finer.

Use of Type III – Portland Cement

When forms need to be removed early

Early opening for traffic conditions Notes, Figures, and Tables:

Effect of Cement Fineness

The finer a Portland cement is ground, the more surface area is available for hydration, thus allowing more cement gel to form at early ages. Disadvantages of finer ground cement:

Higher heat of hydration at early ages

Increased drying shrinkage of the concrete.


Table 4-1 pg 67 Design & Control of Concrete Mixtures (D & C) Specifications and Classes of Supplementary Cementitious Materials Ground granulated iron blast-furnace slags - ASTM C 989 (AASHTO M 302)

Grade 80 o Slags with a low activity index

Grade 100 (WisDOT) o Slags with a moderate activity index

Grade 120 (WisDOT) o Slags with a high activity index

Fly ash and natural pozzolans - ASTM C 618 (AASHTO M 295)

Class N o Raw or calcined natural pozzolans including: o Diatomaceous earths o Opaline cherts and shales o Tuffs and volcanic ashes or pumicites o Calcined clays, including metakaolin, and shales

Class F o Fly ash with pozzolanic properties

Class C (WisDOT) o Fly ash with pozzolanic and cementitious properties

Silica Fume – ASTM C 1240

Supplementary Cementitious Materials

(Traditionally called Mineral Admixtures)

Fly Ash

Slag

Silica Fume


Fly Ash

Most widely used supplementary cementitious material in concrete is a finely divided residue (powder resembling cement) results from the cooling of combustion gases of pulverized coal in electric power generation plants.

Most fly ash particles are solid spheres although some are hollow spheres. See photo on

page 69 of Design & Control.

Portland cement has solid angular particles

The relative density (specific gravity) of fly ash ranges from 2.2 to 2.8

Classes of Fly Ash Normally Used in Concrete

Class C Fly Ash (WisDOT) Class F Fly Ash

“WisDOT recognizes only Class C Fly Ash.”

Class C Fly Ash

Fly ash with pozzolonic and cementitious properties. Calcium oxide content of approximately 15% to 30% by weight. These types of ashes will hydrate when exposed to water in less than 45 minutes.

Class F Fly Ash

Fly Ash with pozzolonic properties Generally low-calcium (less than 10% CaO) fly ashes with carbon contents usually less than 5%, but some may be as high as 10%. Notes, Figures or Tables:


WisDOT QMP Specification: Fly Ash and Slag Replacement

Fly Ash, Class C, % Slag, Grade 100 or 120, %

Concrete Pavement (SCM optional) 0 – 30 0 – 50

Concrete Structures (SCM required) 15 – 30 20 – 30

QMP Pavement Projects (Std Spec 715.2.3.1): Provide a minimum cement content of 565 pounds per cubic yard (335 kg/m3), except if using type I or III cement in a mix where the geologic composition of the coarse aggregate is primarily igneous or metamorphic materials, provide a minimum cement content of 660 pounds per cubic yard (392 kg/m3). The contractor may partially replace Portland cement with fly ash at a replacement ratio of not less than one pound (kg) of fly ash per one pound (kg) of cement up to a maximum fly ash content of 30% of total cementitious material. Alternatively, the contractor may use slag as a partial replacement for cement at a replacement ratio of not less than one pound (kg) of slag per one pound (kg) of cement. For slip-formed concrete pavement do not exceed a maximum slag content of 50% of the total cementitious material. For concrete pavement not slip-formed, do not exceed a maximum slag content of 30% of total cementitious material. Alternatively, the contractor may use a combination of fly ash and slag up to a maximum combined fly ash and slag content of 30 percent. Ensure that fly ash conforms to standard spec 501.2.6 and slag conforms to standard spec 501.2.7. QMP Structures Projects (Std Spec 715.2.3.2): Ensure that the cementitious content for grade A concrete equals or exceeds 565 pounds per cubic yard (335 kg/m3). For all superstructure and substructure concrete, unless the engineer approves otherwise in writing, conform to one of the following: 1. Use class C fly ash or grade 100 or 120 slag as a partial replacement for Portland cement.

For binary mixes use 15% to 30% fly ash or 20% to 30% slag. For ternary mixes use 15% to 30% fly ash plus slag in combination. Percentages are stated as percent by weight of the total cementitious material in the mix.

2. Use a type IP, IS, or I(SM) blended cement. Note: The contract documents for each project should be checked closely for any variations in these requirements.


Slag Cement

Blended Cements

Type IS Portland Blast-Furnace Slag Cement

Used in general concrete construction

Slag cement is manufactured by:

Either interground with Portland cement clinker, or; Separately ground and blended with Portland cement, or; Produced with a combination of intergrinding and blending.

The blast-furnace slag content of this cement is between 25% and 70% by weight.

Disadvantages of Granulated Slag

More severe bleeding and segregation

No high ultimate strength as reported in fly ash (Pozzolon)

Ground Granulated Blast-Furnace Slag Made from iron blast-furnace slag Air-cooled slag does not have the hydraulic properties of water-cooled slag


Type I (SM) Slag Modified Portland Cement

Used for general concrete construction This type is manufactured by:

o Intergrinding Portland cement clinker and granulated blast furnace slag. o Blending Portland cement and finely ground granulated blast-furnace slag. o Combination of intergrinding and blending.

Several of the blended cements have a lower early strength gain as compared to Type I cement.

If a blended cement is diluted by the addition of more pozzolon or slags, concrete should be tested for changes in strength, durability, shrinkage, permeability, and other desirable properties. Cold placement and curing temperatures may significantly decrease strength gain and increase time of set in high slag or pozzolon content blended Note, Figures, and Tables:

Student Problem: WisDOT Fly Ash Replacement Problem The contractor is designing a WisDOT A-FA concrete mixture for a bridge project. No previously designed mixture is available. The minimum cement content to be used on the paving project is 565 lbs. (256.3 kg). The contractor plans to use 20% fly ash replacement at a replacement ratio of 1.3 cement to 1.0 fly ash. Calculate the proportions of the cementitious materials to be used for cement and fly ash. NOTE: Slag content could be calculated the same way. Formulas: Final Cement Content = Replace Fraction x Base Cement Cont x [1-(Percent SCM Replace/100)] Replace Fraction + [(1 – Replace Fraction) x (Percent SCM Replace/100)] Final SCM Content = Replace Fraction x Base Cement Cont x [Percent SCM Replace/100)] Replace Fraction + [(1 – Replace Fraction) x (Percent SCM Replace/100)]

Inputs are: Final Cement Content = Final content of Portland cement in lb/cy or kg/m3. Final SCM Content = Final content of fly ash or slag in lb/cy or kg/m3.

Replacement Fraction = Fractional ratio of replacement material to cement (i.e. – a replacement ratio of 1.3:1.0 is calculated as a fractional ratio of 1.3/1.0).

Base Cement Content = The base content of Portland cement in lb/cy or kg/m3. Percent SCM Replacement = The desired percent of fly ash or slag expressed as a

percent of the final total of cementitious materials.

Percent SCM Replacement (as a percent of total cementitious materials). Solution:

Cement = 1.3 x 565 x (1 – 0.2) = 587.6 = 474 lb 1.3 + [(1 – 1.3) x 0.2] 1.24 Fly Ash = 1.3 x 565 x 0.2 = 146.9 = 119 lb Total Cementitious = 593 lb 1.3 + [(1 – 1.3) x 0.2] 1.24 Check: Cement = 474/593 x 100% = 80% Fly Ash = 119/593 x 100% = 20%

TOPIC F: Admixtures – Air-Entraining, Water Reducers plus F-1 Superplasticizers, Retarders, Non-Chloride Accelerators, and

Troubleshooting Guide for Solving Air Content Problems



Admixtures are classified as:

Air-Entraining

Water-Reducing

Retarding

Accelerating

Superplasticizers

Supplemental Cementitious Materials

Miscellaneous Admixtures, such as: o Workability o Bonding o Damp-proofing o Permeability-reducing o Grouting o Gas forming o Coloring o Corrosion inhibiting o Pumping admixtures

Major Reasons for Using Admixtures:

Reduce costs of concrete construction

Achieve certain properties in concrete more effectively

Ensure the quality of concrete during stages of mixing, transporting, placing, and curing in adverse weather conditions

Overcome certain emergencies during concrete operations. Notes, Figures, and Tables:



Effectiveness of Admixture Depends On:

Type of admixture

Brand of admixture

Amount of cement

Water content

Aggregate shape

Gradation

Proportion

Mixing Time

Slump

Temperatures of concrete and air

Please bear in mind that no Admixtures of any type or amount can be considered a substitute for good concreting practice.

Admixtures being considered for use should meet applicable specifications. (Refer to Table 7-1 on Page 118 & 119 of D & C for Concrete Admixtures by Classification.)

Admixtures being considered for use in concrete should be trial tested with other admixtures (if used) and job materials at temperatures and humidity anticipated on the job.

Reasons for Trial Batching Admixtures:

► Ensure compatibility with other admixtures

► Monitor admixtures to ensure desired effects have been achieved

► Determine correct amount of admixture dosage and to verify optimum amount to be used



Air-entraining Admixtures

► Used purposely to entrain microscopic air bubbles in concrete to improve the durability of

the concrete exposed to moisture during cycles of freezing and thawing ► Improve concrete resistance to surface scaling caused by chemical deicers ► Improve workability of concrete ► Reduces segregation and bleeding

Water-Reducing Admixtures

General Classification Desired Effect Water reducer Reduce water content at least 5% Water reducer and accelerator Reduce water content (minimum 5%) & accelerate Water reducer and retarder Reduce water content (minimum 5%) & retard set Water reducer – high range Reduce water content (minimum 12%) Water reducer – high range & retarder Reduce water content (minimum 12%) & retard set Water reducer – mid range Reduce water content (between 6 and 12%) without

retarding

Specifications and methods of testing air-entraining admixtures are given in ASTM C260 and C231.

TROUBLESHOOTING GUIDE FOR SOLVING AIR CONTENT PROBLEMS: Chapter 9, Design & Control – Effect of Various Factors on Control of Air In Concrete

Table 9-1 Page 158, Table 9-2 & Table 9-3 Page 161, Table 9-4 Page 162, Table 9-5 & 9-6 Page 163



Other Effects of Water-Reducing Admixtures

Used to reduce the quantity of mixing water

Reduce water-cement ratio

Increase strength and other physical properties

Increase slump

Typical water reducers can reduce water content by approximately 5% to 10%

High-range water reducers can reduce water content by 12% to 30%

Superplasticizers)

Adding a water-reducing admixture to a mix without reducing water content will

produce a much higher slump.


Water-Reducing Admixtures (Continued)

Water-reducing admixtures may cause a slight increase in chemical shrinkage due to more efficient wetting of cement particles.

Reducing water and water-cement ratio can produce strengths 10% to 25% greater than the original mixture.

Water reducers may decrease, increase, or have no effect on bleeding.

May retard setting time of concrete.

May entrain some air on concrete.

Some water reducers are more effective in lean mixtures.

The effects of water-reducing admixtures vary greatly by chemical composition.



Retarding Admixtures

Used to retard or delay the rate of setting of concrete. High temperatures (85o F or higher) are the main cause of increased

hardening. Another alternative is to reduce temperature of mixing water or

aggregates Retarders do not reduce the initial temperature of the concrete.

Use of Retarders

Offset accelerating effect of hot weather on the setting of concrete

Delay initial set time of concrete

Delay set for special effects, such as exposed aggregate surface

Most retarders act as water-reducers, frequently called water-reducing

retarders

May reduce early strengths (first 1 to 3 days)



Accelerating Admixtures

Other Methods to Accelerate Concrete Strength

Use Type III high-early-strength Portland cement.

Lower water-cement ratio by adding 100-200 pounds of additional cement per cubic yard of concrete.

Curing a higher temperature

Cover with insulated blankets

Purpose is to accelerate development of strength at an early

age by decreasing the initial set time of the concrete mixture.

Most common accelerator used is Calcium Chloride (CaCl2).

Disadvantages of Calcium Chloride:

Causes increase in drying shrinkage. Potential reinforcement corrosion Causes discoloration (darkens concrete) Increases the potential for Scaling

The use of calcium chloride or admixtures containing soluble chlorides is not recommended under the following conditions: Prestressed concrete because of possible corrosion hazards. Concrete exposed to alkali-aggregate reactions or exposed to soil or water containing

sulfates. In hot weather, generally Massive concrete pavements.



“Chloride-based accelerators are prohibited from use in all WisDOT work except for PCC pavement rehabilitation patching, or in gaps or access points in new pavement where opening strengths are required by WisDOT in 8 hours or less.”

Calcium Chloride is not an antifreeze agent.

Calculating Calcium Chloride

Regular flake contains minimum of 77% CaCl2 Concentrated flake, pellet, or granular forms contain a minimum of 94%

CaCl2

Overdose can result in placement problems and can be detrimental to concrete.

Causes rapid stiffening Large increase in drying shrinkage Corrode reinforcement strength Loss of strength

Non-Chloride, Non-corrosive Accelerators

Many are available for use in concrete where chlorides are not recommended.

Handling of Calcium Chloride:

Should be added as part of the mixing water

If added dry, all particles will not be completely dissolved during mixing

Addition of Calcium Chloride shall not exceed more than 2% by weight of cement.



A water reduction of 12% to 30% can be obtained through the use of superplasticizers.


Addition of superplasticizers to a 3 inch slump concrete can easily produce with a 9 inch slump.

Flowing concrete, defined, ASTM C1017, as having a slump greater than 7-1/2 inches while maintaining cohesive properties.

Excessively high slumps may cause concrete to segregate.

Superplasticizers (High-Range Water Reducers)

Water reducers meeting ASTM C1017 and C494 Types F and G specifications Added to concrete with low to normal slump and water-cement ratio to make high-

slump flowing concrete. Added to concrete to minimize W/C ratio and produce high-strength performance

concrete.

Reduced water content and water-cement ratio can produce concretes:

10,000 PSI compressive strengths

Increased early strength gain

Reduced chloride-ion penetration

TOPIC G: Combined Aggregate Gradation G-1


Combined Gradation If aggregate control by combined aggregate gradation is selected, the following information applies. Following completion of individual sieve analysis calculations for each simultaneous sampling and testing of fine and coarse aggregates, the QC staff shall determine by calculation the combined gradation proportions. The special provision specifications state that fine and coarse aggregate fractions should each substantially conform to gradation limits in the WisDOT Standard Specifications (Section 501.2.5 Aggregates), but aggregate gradation compliance will be determined by a combined gradation of the three individual aggregates. Student Problem: The contractor is considering the use of a combined aggregate gradation for a concrete

mixture. Use the “Combined Aggregate Gradation Calculations Worksheet@ (Attachment 1) to

perform the combined aggregate gradation. Given the following data: Coarse and Fine Sieve Analysis Information:

Sieve Size C.A. #2 C.A. #1 F.A.

2" 100 100 100

1-1/2" 96 100 100

1" 32 100 100

3/4" 12 97 100

1/2” 8

62 100

3/8" 3 27 100

#4 3 6 96

#8 2 2 87

#16 2 1 73

#30 2 1 42

#50 2 1 16

#100 2 1 4

#200 1.5 1.0 3.0

Proportions of Combined Gradation: Coarse Aggregate (C.A.) #2 = 25% Coarse Aggregate (C.A.) #1 = 35% Fine Aggregate (F.A.) = 40%


Combined Aggregate Gradation Instructions (Attachment 1)

Step 1 - Complete project data information.

Step 2 - Obtain and fill in the appropriate aggregate proportions selected for the combined gradation.

Step 3 - Fill in the three aggregate gradations (i.e., D, E, F) from the appropriate

aggregate test data sheets. Use unwashed sieve analysis data when permissible by the test method (include the #8 and #30 sieves for information).

Step 4 - Calculate the combined gradation (G) by multiplying each aggregate grading

by the corresponding blend percentage for each sieve fraction and adding the results for the three aggregates. Calculate to 0.1% for each sieve fraction except 0.01% for the #200 sieve fraction. Round the total (G) to the nearest 0.1% percent passing except to 0.01% for the #200 sieve fraction.

Step 5 - Calculate the lower specification limits (LSL) and upper specification limits

(USL) values by multiplying the appropriate blend percentage for each aggregate (section 501) LSL and USL values.

Step 6 - Calculate the combined LSL and USL by adding the three aggregate LSL and

USL values and rounding to the nearest whole percent, except to 0.1% for the #200 sieve fraction.


Attachment 1 – Combined Aggregate Gradation Calculations Sheet (Solution on Page G-11)

TOPIC G: Combined Aggregate Gradation G-4 Analysis of Combined Gradation Data The data resulting from the previously described combined gradation analysis is to be used by the QC personnel for evaluation of the mixture quality and for control chart plotting. In order to present a visualization of the data and to facilitate recognizing significant changes, it is suggested the data be analyzed in some manner. The contractor may choose to make a further analysis of only certain samples, rather than all, as he/she finds necessary for quality control. Processes of analysis other than presented here may be preferred by the contractor to accomplish the QC objectives. The steps that follow are suggested to assist the QC staff both in visualizing the data generated and clarifying adjustment that may be needed in the process. The contractor may choose other analysis methods to stay abreast of the test data. Next, complete Attachment 2 by summarizing the principle gradations from Attachment 1 and performing the indicated calculations for the percent total retained and percent between sieves.

Mix Design Note: Aggregate Percentage Blends – Maximum % Fine Aggregate on BOD Basis (% FA = % Passing #4 Sieve) [% Of the Aggregate portion of the mix.]

Std Spec Book 501 1 (Individual)

QMP 2 (Combined)

Crushed Gravel - 40 42

Crushed Stone - 45 47

1 Section 501.3.2.2 Table & Note 8 on pages 225 & 226. 2 Std Spec 715.2.2 Combined Aggregate Gradation.


Step 7 - Transfer the Combined % Passing data from column (G) on Attachment 1 to the appropriate column on Attachment 2.

Step 8 - Transfer LCL & UCL data from STEP 6 on Attachment 1 to the appropriate

columns on Attachment 2.

Step 9 - Calculate the cumulative Combined % Retained above each sieve by entering 100 and then subtracting the % passing for each sieve (G).

Step 10 - Calculate the Combined % Between Sieves (ie – % retained on each sieve)

by entering in your calculator the % Retained for the sieve you are calculating and subtracting the % Retained on the next larger sieve.

Note: On this worksheet, round to 0.1% for each sieve fraction except 0.01% for the

#200 sieve. Once calculations and graphing have been completed, report sieve test results by rounding to 1% except to 0.1% for the #200 sieve.

Attachment 2 – Summary of Combined Gradation Information and Specification Limits

(Solution on Page G-12)

TOPIC G: Combined Aggregate Gradation G-6 Next, plot the combined gradation and limits from Attachment 2 on the gradation chart on Attachment 3 - Aggregate Gradation Chart (Sieve Sizes Raised to 0.45 Power). Attachment 3 - Aggregate Gradation Chart is a visual of where the combined gradation lies within the specification limits. If desired, the contractor WILL BE ALLOWED TO ADJUST the individual aggregate proportions (blend) within the established limits to obtain a more central grading. Only one such adjustment will be allowed. This adjustment is to provide the contractor with a more workable operating range within the limits (i.e. before approaching or crossing either the warning or control limits). This feature will permit the contractor to utilize the individual aggregates more efficiently and economically. After making a blend change, calculations of moving average values shall start over. It shall be understood that the contractor will notify the engineer of adjustments made in the process outlined above. While movement within the specification envelope will be permitted to benefit the contractor’s use of aggregate, any blend change resulting in a combined gradation outside the established envelope will constitute a significant adjustment to the mixture design. Such adjustments will require approval of the engineer and re-establishment of the specification limits following the previously outlined procedures.


Attachment 3 – Aggregate Gradation Chart (Sieve Sizes Raised to the 0.45 Power) (Solution on Page G-13)


Figure G.1: Maximum Density Curves for 0.45 Power Gradation Graph (each curve is for a different maximum aggregate size)

TOPIC G: Combined Aggregate Gradation G-9 Finally, use the calculated percent between sieves from STEP 10 on Attachment 2 to plot the particle size distribution chart shown in Attachment 4 – Particle Size Distribution Chart.

Attachment 4 –Combined Percent Retained Particle Size Distribution Chart The particle size distribution chart is plotted utilizing the individual percent retained (calculated from the percent between each sieve) versus the appropriate sieve sizes. The purpose of this chart is to help the concrete mix designer develop a better understanding of the most economical grading based on the individual percent-retained sieves. Past historical data indicates the particle size distribution chart should take the shape of a “haystack,” as illustrated, producing the most economical well-graded concrete mixture. Key sieves have been identified as the No. 4, No. 8, and No. 16 near the top of the grading curve. This information was obtained from Roger Larson, Senior Pavement Engineer, Federal Highway Administration, Washington, D.C.


PARTICLE SIZE DISTRIBUTION CHART

______ % #2 STONE ______ % #1 STONE ______ % SAND 25

20

15

10

5

0 2” 1½” 1” ¾” ½” 3/8” #4 #8 #16 #30 #50 #100 #200

SIEVE SIZE

Attachment 4 – Percent Retained Particle Size Distribution Chart (Solution on Page G-14)


Attachment 1 – Combined Aggregate Gradation Calculations Sheet


Attachment 2 – Summary of Combined Gradation Information and Specification Limits


Attachment 3 – Aggregate Gradation Chart (Sieve Sizes Raised to the 0.45 Power)


PARTICLE SIZE DISTRIBUTION CHART

25 % #2 STONE 35 % #1 STONE 40 % SAND 25

20

15

10

5

0 2” 1½” 1” ¾” ½” 3/8” #4 #8 #16 #30 #50 #100 #200

SIEVE SIZE

Attachment 4 – Percent Retained Particle Size Distribution Chart

TOPIC G: Combined Aggregate Gradation G-15 How can the Percent Retained Graph be interpreted? Read the following four pages which are excerpts from the U.S. Air Force Engineering Technical Letter 97-5 entitled: Proportioning Concrete Mixtures with Graded Aggregates for Rigid Airfield Pavements.

TOPIC H: Theory of Portland Cement Concrete Mix Design H-1


Theory of Proportioning Normal Concrete Mixtures The proportioning of normal concrete mixtures involves determining the most economical blend of coarse and fine aggregates, potable water, cement, air, and the necessary admixtures to provide a strong durable mixture that will satisfy the performance requirements governed by the specifications. Not including air, concrete is made up of 7 to 14 percent cement, 15 to 20 percent water, and between 60 to 78 percent aggregate. A mix designer must understand the following principles before starting a concrete mix design. # Too much coarse aggregate produces a very harsh mix with limited workability and

plasticity characteristics. # Too much sand in a concrete mixture requires additional water to be added because of

the increased surface area of the smaller particles. # Increased water content leads to adding more cement to the concrete mixture to satisfy

the water cement ratio requirement, which, in turn, raises the cost of the product. A concrete mix designer must carefully choose the proportions of all materials and conduct concrete mix trial batches to verify the concrete mixture will perform to the strength and durability performance parameters, be economical, and meet finishability and workability standards. Three common methods of proportioning normal concrete mixtures are: # Proportioning from field data # Proportioning by trial mixtures (See ASTM C 192 for laboratory batching procedures) # Volumetric absolute volume method

Proportioning From Field Data Previously used concrete mix proportions can be submitted for approval if the average compressive strength and the corresponding standard deviation from past performance data meet ACI 318 requirements. See pages 241 and 242 of Design and Control for details outlining the procedure. The data used in this procedure should come from concrete with a specified compressive strength within 1,000 psi of the strength specified for the project. If sufficient field data is available, a PCC Technician II certification is not required to submit the mix proportions. This procedure is not necessary for QMP Pavement projects.

TOPIC H: Theory of Portland Cement Concrete Mix Design H-3 Volumetric Absolute Volume Method Design Code ACI 211.1 was created by the American Concrete Institute’s Committee 211 is titled Standard Practice for Proportioning Concrete Mixtures. The code illustrates both a weight method and a volume method for concrete mixture proportioning. The volumetric method is the more accurate and will be discussed in the next section.

Specifications A mix designer must obtain the latest copy of the specification parameters. In this case, an example will be illustrated using the WisDOT Quality Management Program, Portland Cement Concrete Pavement. A Concrete Pavement Mix Report is required for WDOT concrete paving projects. Volumetric Absolute Volume Method Example Once the mix design specification parameters have been reviewed, it is time to work through a volumetric absolute volume method example problem, keeping in mind all specification parameters.

Cement Type I, ASTM C 150

Coarse Aggregate 3/4" in. maximum sized crushed stone particles

Oven-dry relative density (specific gravity) of 2.68

Absorption of 0.5%

Oven-dry rodded unit weight of 100 lb. per cu. ft.

Field moisture is 2.0%

Fine Aggregate Natural sand (round particles)

Oven-dry relative density (specific gravity) of 2.64

Absorption of 0.7%

Field moisture is at 6.0%

Fineness modulus is 2.80

TOPIC H: Theory of Portland Cement Concrete Mix Design H-4 Air-entraining Admixture

Wood-resin type, ASTM C 260

Coarse Aggregate Size Specified a maximum size of 2 inches (50 mm)

Water-Cement Ratio Refer to latest specification

Air Content Refer to target air of latest specification

Slump As no slump was specified, for proportioning purposes, three (3) inches maximum is generally recommended for pavement and slabs.

Cement Content - Cementitious Materials Minimum cement content = Refer to latest specification in Standard Specification Section 715.

Relative density (specific gravity) is cement is usually 3.15. If the test data for your specific source is not available, the relative density (specific gravity) of fly ash can be assumed to be 2.65, and the relative density (specific gravity) of slag 2.90

Class C fly ash may be used as a partial replacement for Portland cement at a replacement ratio of 1.0 lb of fly ash added per 1.0 lb of cement removed, up to a maximum of 30% of total weight of cementitious materials for pavements (30% for structural masonry too).

Grade 100 or 120 slag may be used as a partial replacement for Portland cement at a replacement ratio of 1.0 lb of slag added per 1.0 lb of cement removed, up to a maximum of 50% of total weight of cementitious materials for pavements (30% for structural masonry).

TOPIC H: Theory of Portland Cement Concrete Mix Design H-5 Water Content

Lbs. per cu. yd. water = ?

Lb. per cu. yd. cement = 565

Water cement ratio = 0.42 (used in this example but varies between pavement and bridge specification - always review latest current specification) Water-Cement Ratio = lbs/cu yd Water lbs/cu yd Cementitious 0.42 = X lbs/cu yd Water 565 lbs/cu yd 565 lbs/cu yd x 0.42 = X lbs/cu yd Water

Coarse Aggregate Content

3/4 in. (19 mm) maximum aggregate has been selected for this example.

The percentage of coarse aggregate to be used is determined from Table 12-4 entitled Bulk Volume of Coarse Aggregate Per Unit Volume of Concrete found on page 236 of Design & Control. The fineness modulus is 2.80 and the maximum aggregate size of aggregate is 3/4 in. (19 mm). The recommended percent coarse aggregate to be used is 0.62 percent for this example.

The quantity of coarse aggregate is determined by multiplying the unit weight per cu. ft. (100 lb/cu ft) by (27 cu ft) by the percentage of coarse aggregate to be used (0.62% = 1674 lb/cu yd of concrete.

Unit weight of 100 lb/cu ft x 27 cu ft x 0.62 = 1674 lb/cu yd

Note: If two coarse aggregates are used, proportion them separately to total 1674 lb/cu cy by multiplying by decimal percentages that totals 1.00. Because they may have different relative densities, their volumes should be calculated separately.

237 lbs/ cu yd = X


Admixture Content

The target air content for the concrete mixture is 7.0%. The air-entraining admixture manufacturer recommends a dosage rate of 0.9 fl oz per 100 lb (also called cwt) of cement.

Calculation: 0.9 fl oz x 565 lb/cu yd = 5.1 fl oz/cu yd 100 lb

Fine Aggregate (FA) Content At this point, all the ingredients are known except for the fine aggregate. In the absolute volume method, the volume of fine aggregate is determined by subtracting the absolute volume of the water, cement, and coarse aggregate and is calculated by dividing the known weight of each by the product of their relative density (specific gravity) and the unit weight of water. The volume computations are as follows: Water = 237 = 3.80 cu ft

1 x 62.4

Coarse Aggregate = 1674 = 10.01 cu ft What if we use #2 Coarse Aggregate = ? 2.68 x 62.4 Cement = 565 = 2.87 cu ft What if we use Fly Ash = ? 3.15 x 62.4 Air = 7.0 x 27 = 1.89 cu ft 100 Total Volume of Known Ingredients = 18.57 cu ft The calculated absolute volume of fine aggregate is: 27.00 - 18.57 = 8.43 cu ft The weight of dry fine aggregate is: 8.43 x 2.64 x 62.4 = 1389 lb NOTE: If you add or remove cement, remove or add an equal volume of FA to maintain yield.

TOPIC H: Theory of Portland Cement Concrete Mix Design H-7 The mixture now has the following proportions before trial mixing for one cubic yard of concrete: Water 237 lb Cementitious Material 565 lb Coarse Aggregate (Dry) 1674 lb Fine Aggregate (Dry) 1389 lb

Total Weight 3865 lb Air-entraining Admixture: 5.1 fl oz/cu yd Slump 3 in. (±3/4 in. for trial batch) Air Content 7% (± 0.5% for trial batch) Estimated Density (using SSD aggregate) 1682 1399 = [237 + 565 + (1674 x 1.005*) + (1389 x 1.007*)] = 143.8 lb/cu ft 27 Note: *Absorption is added back to the dry aggregates when using SSD aggregates.

Coarse Aggregate: (0.5% absorption 100) + 1 = 1.005

Fine Aggregate: (0.7% absorption 100) + 1 = 1.007 Summary of Mix Proportions using SSD weights (report these to WDOT & Plant Operator) Water 237 lb Cementitious Material 565 lb Coarse Aggregate (Dry) 1682 lb Fine Aggregate (Dry) 1399 lb

Total Weight 3883 lb Air-entraining Admixture: 5.1 fl oz/cu yd

TOPIC H: Theory of Portland Cement Concrete Mix Design H-8 Moisture Corrections Moisture corrections are needed to compensate for moisture in the field aggregates. The mixing water added to the batch must be reduced by the amount of free moisture contributed by the aggregate. Field moisture content (MC) tests indicated that the coarse aggregate is 2 % and the fine aggregate is at 6%. Coarse Aggregate (2.0% MC) = 1674 lb x 1.02 = 1707 lb. Fine Aggregate (6.0% MC) = 1389 lb x 1.06 = 1472 lb. Absorbed water does not become part of the mixing water and must be excluded from the water adjustment. Surface moisture contributed by: Coarse aggregate = 2.0% - 0.5 (absorption %) = 1.5 % Fine aggregate = 6.0% - 0.7 (absorption %) = 5.3 %

New Water Estimate: 25.1 73.6 237 - (1674 x 0.015) - (1389 x 0.053) = 138.27 lb Estimated revised batch weights for one cubic yard of concrete are to include actual field moisture contents. Water (to be added) 138 lb Cement 565 lb Coarse Aggregate (2% MC, wet) 1707 lb Fine Aggregate (6% MC, wet) 1472 lb

Total 3882 lb Air-entraining Admixture 5.1 fl oz

TOPIC H: Theory of Portland Cement Concrete Mix Design H-9 Trial batch At this stage, the estimated batch weights should be checked by means of trial batches or by full size field batches. Mix adequate concrete to perform air, slump, and three 6 x 12 in. cylinders required for 28 day tests. Minimum volume of trial batch = 0.25 + 0.2 + 3 (0.2) = 1.05 Scale down weights to produce 2.0 cu ft of concrete using ratio 2/27. Laboratory Trial Batch Note: 2/27 = 0.074 Water 138 x 0.074 = 10.29 lb Cement 565 x 0.074 = 41.81 lb Coarse Agg.(wet) 1707 x 0.074 = 126.32 lb Fine Agg.(wet) 1472 x 0.074 = 108.93 lb

Total = 287.35 lb Air-entraining admixture 5.1 x 0.074 = **0.38 fl oz. x 29.57353 ml /fl oz = 11.2 ml Note: **Due to small amount of admixture, convert fluid ounces to milliliters by multiplying fluid ounces by 29.57353 to improve measurement accuracy by measuring in ml.

Topic I: Hot/Cold Weather Concreting I-1


Fig 16-8. Typical plastic shrinkage cracks.

Hot Weather Concreting Can Create:

Increased water demand

Accelerated slump loss

Increased rate of setting

Increased tendency for plastic cracking

Difficulties in controlling entrained air

Critical need for prompt early curing

Add Water at Job Site May Effect:

Decreased strength

Decreased durability and water tightness

Non-uniform surface appearance

Increased tendency for drying shrinkage Note: Only by taking precautions to alleviate these difficulties in anticipation of hot weather conditions, can concrete work proceed smoothly.


Notes, Figures and Tables:

Effects of High Concrete Temperatures

As concrete temperatures increase, naturally there is a loss in slump usually compensated by adding more water on the job.

Adding water without adding cement results in a higher water-cement ratio, therefore lowering the strength and durability properties of the concrete.

(Continued on next page)

When to Take Precaution

A concrete temperature of 50ºF to 60ºF is desirable but not always practical.

Effects of a high concrete temperature should be anticipated probably somewhere between 75ºF and 100ºF.

The limit should be established for conditions at the job site based on trial-batch tests at the limiting temperature.

WisDOT Specifications indicate action is required at 80ºF. See Section 501.3.8.2 of the Standard Specifications.


Fig 16-2. The water requirement of a concrete Fig 16-4. Effect of high concrete temperatures mixture increases with an increase in concrete on compressive strength at various ages (Klieger temperature (Bureau of Reclamation 1981). 1958).

Effects of High Concrete Temperatures (Cont’d)

As shown in Figure 16-2, if the temperature of freshly- mixed concrete is increased from 50° F to 100° F, about 33 lb. of additional water is needed per cubic yard of concrete to maintain the same 3 in. slump.

This additional water could reduce strength by 12% to 15% and produce a compressive strength cylinder test results that may not comply with specifications.

Refer to Figure 16-4, which demonstrates the effect of high initial concrete temperatures on compressive strength.

Tests using the identical concretes off the same water-cement ratio show that while higher concrete temperatures give higher early strength than 73° F, at later stages the ages of the concrete are lower. (If the water had been increased to maintain the same slump, the reduction in strength would have been much greater.)


Notes, Figures, and Tables: Fig. 16-1. Liquid nitrogen added directly into a truck mixer at a ready mix plant.

Other Harmful Effects of High Temperatures

Setting time is significantly reduced. High temperature increases the rate of hardening and shortens length concrete can be transported, placed and finished. Setting time is reduce by two or more hours with the 20°F in concrete temperature.

Additional tendency for cracks to form before and after hardening: o Rapid evaporation of water from freshly placed concrete can cause plastic-

shrinkage cracks before the surface has hardened. o Cracks may also develop in the hardened concrete because of increased

drying shrinkage due to a higher water content or thermal volume changes at the surface due to cooling.

Air Entrapment is also effected by elevated temperatures. o An increase in the amount of air-entraining mixture is required for same

desired effect.

Because of detrimental effects of high concrete temperatures, operations in hot weather should be directed toward keeping the concrete as cool as is practicable.


Considerations to Reduce Concrete Temperatures During Hot Weather Use materials that have a good record in hot-weather conditions. For example, light colored

aggregates reflect sunlight so they tend to stay cooler. Using and increased amount of fly ash or slag will reduce heat of hydration and therefore temperature.

Consider scheduling concrete placements at night or during favorable weather conditions. Use

evaporation nomograph (pg 323, Design & Control) to predict favorable weather conditions for placing concrete.

Cool equipment including mixing drums, chutes, conveyor belts, hoppers, pump lines, by

shading them where possible, painting them white, or spraying water or covering them with wet burlap to reduce solar heat.

Sprinkle concrete aggregates enough to replace evaporation to keep them above SSD. Over

sprinkling causing runoff is not necessary. Shade aggregate stockpiles if possible. Consider using supplementary cementitious materials that slow the rate of setting and the rate

of slump loss. Cool concrete ingredients focusing on concrete aggregates and mix water first. Note: A 10 °F

change in cement temperature will change the concrete temperature only about 1 °F. Cool concrete using ice or liquid nitrogen.

Use a concrete consistency that allows rapid placement and consolidation.

Try to avoid prolonged mixing, even if only at agitating speed. Intermittently stopping the mixer

may help reduce heat of hydration. Reduce the time of transport, placing and finishing. Reduced time reduces effect of heat of

hydration. Equation for estimating concrete temperatures based on ingredient temperatures and the addition of ice (See pg 319, Design & Control for example calculations):

T = 0.22(TaMa + TcMc) + TwMw + TwaMwa - 112Mi

0.22(Ma + Mc) + Mw + Mwa + Mi T = temperature of the freshly mixed concrete, (°F) Ta, Tc, Tw, and Twa = temperature in °F of aggregates, cement, added mixing water, and free water on aggregates, respectively Ma, Mc, Mw, and Mwa = mass, (lb), of aggregates, cementing materials, added mixing water, and free water on aggregates, respectively Mi = mass of ice in lb. Note: Ice volume should not exceed 75% of total batch water. The maximum temperature reduction from ice is limited to about 20°F.

Topic I: Hot/Cold Weather Concreting I-7 Rate of Evaporation See page 323 of Design & Control (Also CMM 5-25 Figure 1) Fig 16-9. Effect of concrete and air temperatures, relative humidity, and wind velocity on rate of evaporation of surface moisture from concrete. Wind speed is the average horizontal air or wind speed in mph measured at 20 in. above the evaporating surface. Air temperature and relative humidity should be measured at a level approximately 4 to 6 ft above the evaporating surface and on the windward side shielded from the sun’s rays (Menzel 1954).

To use this chart: 1. Enter with air temperature, move up to relative humidity. 2. Move right to concrete

temperature. 3. Move down to wind velocity.

4. Move left: read approximate

rate of evaporation.


EXCERPT FROM: STANDARD SPECIFICATIONS FOR HIGHWAY AND STRUCTURE

CONSTRUCTON – (2012 Edition)

501.3.8.2 Hot Weather Concreting 501.3.8.2.1 General

(1) The contractor is responsible for the quality of the concrete placed in hot weather. For concrete placed under the bid items enumerated in 501.3.8.2.1(2), submit a written temperature control plan at or before the pre-pour meeting. In that plan, outline the actions the contractor will take to control concrete temperature if the concrete temperature at the point of placement exceeds 80 F (27 C). Do not place concrete under these bid items without the engineer's written acceptance of that temperature control plan. Perform the work as outlined in the temperature control plan.

(2) If the concrete temperature at the point of placement exceeds 90 F (32 C), do not place concrete under the following bid items:

Concrete Masonry Bridges Concrete Masonry Retaining Walls Concrete Masonry Bridges HES Concrete Masonry Retaining Walls HES Concrete Masonry Culverts Concrete Masonry Endwalls Concrete Masonry Culverts HES Concrete Masonry Overlay Decks

(3) The department will pay $0.75 per pound for the quantity of ice required to reach a target concrete temperature of 80 F (27 C) if the following conditions are met: 1. The un-iced concrete temperature exceeds 85 F (29 C). 2. The contractor has performed the actions outlined in the contractor's accepted temperature control plan. 3. The contractor elects to use ice.

(4) If the engineer directs the contractor to use ice when the un-iced concrete temperature is 85 F (29) or less, the department will pay $0.75 per pound for that ice.

(5) Notify the engineer whenever conditions exist that might cause the temperature at the point of placement to exceed 80 F (27 C). If project information is not available, the contractor should obtain information from similar mixes placed for other nearby work.

Topic I: Hot/Cold Weather Concreting I-9 Excerpt from the Standard Specifications 2012 Edition continued: 501.3.8.2.2 Bridge Decks

(1) For concrete placed in bridge decks under the bid items enumerated in 501.3.8.2.2(2), submit a written evaporation control plan at or before the pre-pour meeting. In that plan, outline the actions the contractor will take to maintain concrete surface evaporation at or 0.2 pounds per square foot per hour (1kg/m2/hr). Do not place concrete under these bid items without the engineer's written acceptance of that evaporation control plan. If the engineer accepts an evaporation control plan calling for ice, the department will pay $0.75 per pound ($1.65/kg) for that ice. Perform the work as outlined in the evaporation control plan.

(2) If predicting a concrete surface moisture evaporation rate exceeding 0.2 pounds per square foot per hour (1kg/m2/hr), do not place bridge deck concrete under the following bid items: Concrete Masonry Bridges Concrete Masonry Overlay Decks Concrete Masonry Bridges HES

(3) Provide evaporation rate predictions to the engineer under one or more of the following conditions:

1. Conditions exist that might cause concrete surface evaporation to exceed 0.2 pounds per square foot per hour (1kg/m2/hr).

2. The concrete temperature at the point of placement exceeds 80 F (27 C).

3. The engineer requests that information.

(4) Compute the evaporation rate from the predicted ambient conditions at the time and place of the pour using the nomograph, or computerized equivalent, specified in CMM 5-40-20 figure 3. Use weather information from the nearest national weather service station. The engineer will use this information to determine if the pour will proceed as scheduled.

(5) On the day before the pour, the engineer will inform the contractor in writing whether or not to proceed with the pour as scheduled. If the actual computed evaporation rate during the pour exceeds 0.2 pounds per square foot per hour (1kg/m2/hr), the engineer may allow the contractor to complete the pour. If the engineer allows placement to continue, the department will pay $0.75 per pound ($1.65/kg) for the quantity of ice required to maintain concrete surface evaporation at or below 0.2 pounds per square foot per hour (1kg/m2/hr). If ice is not available the department will pay for any actions, beyond those described in the contractor's evaporation plan, required to complete the pour as the engineer directs.



PLASTIC SHRINKAGE CRACKING

Plastic shrinkage cracks sometimes occur in the surface of freshly mixed concrete soon after it was placed and while it is being finished.

Plastic shrinkage cracking is usually associated with hot weather concreting; however, it can occur anytime temperature conditions produce rapid evaporation of moisture from the concrete surface.

The following conditions, singly or collectively, increase the possibility of plastic shrinkage cracking:

o High air and concrete temperature o Low humidity o High winds



On-Site Precautions to Minimize Plastic Shrinkage Cracking

Moisten subgrade and forms.

Moisten concrete aggregates that are dry and absorptive.

Erect temporary windbreakers to reduce wind velocity over the concrete surface.

Erect temporary sunshades to reduce concrete surface temperatures.

Keep freshly-mixed concrete temperature low by cooling the aggregates and mixing water.

Protect concrete with temporary coverings. Evaporation retarders may be sprayed after screeding to retard water evaporation before final finishing operations.

Reduce time between placing and start of curing by eliminating delay in construction.

Protect concrete immediately after final finishing to minimize evaporation (most important to avoid cracking). Use of fog spray to raise relative humidity of ambient air is an effective means of preventing evaporation.


Fig 17-5. Effect of temperature on strength Development of concrete. Fig 17-6. Effect of low temperatures on

concrete compressive strength at various ages.

COLD WEATHER CONCRETING

Cold weather is defined by ACI 306 as “A period when for more than three successive days, the mean daily

temperature drops below 40o F.”

Strength Gain of Concrete at Low Temperature

Temperature effects the rate at which hydration of cement occurs (low temperatures retard the rate of hydration).

If concrete is frozen and kept frozen above about 14oF, it will gain strength slowly.

Below 14oF, cement hydration and concrete strength gain cease.

Refer to Figure 17-5. Specimens for the lower curve were made at 40oF and placed immediately in a curing room at 25 oF. Both curves represent 100% relative humidity curing for first 28 days followed by 50% relative humidity curing.

Note in Figure 17-6, concrete cast and cured at 40 o F and 55 o F had relatively low strength for the first week; but after 28 days (when all specimens were moist-cured at 73 oF) strengths for 40 oF and 55 oF concretes grew faster than the 73 oF concrete at one year were slightly higher.

TOPIC J: Statistical Analysis of Compression Tests – J-1 Percent Within Limits (PWL) Determination


Introduction How are WDOT incentive/disincentive amounts calculated on structures & pavement

projects? What is a “Bell” Curve? How is my cylinder strength data reported to WDOT?

What is a Bell Curve? Its technical name is a Normal Distribution Curve. The primary components of the curve are listed below:

The X-axis is compressive strength test results on 6” x 12” cylinders.

The Y-axis is the number of times a compressive strength value occurred.

The curve has a single peak centered on the mean (average).

The two tails on the curve never reach the X-axis.

The location and shape of the curve is determined by the mean and the standard deviation.

The area under the curve is the probability, expressed in %, that test results from a to b are likely to occur based on previous test data. If a & b are specification limits, then the area under the curve is the Percent Within Limits (PWL).

QUESTION: If the specification limit for concrete is 4,000 psi, where on the Figure 1 graph would

you like that value to fall? Left edge, center or right edge of the curve?

Bell Curve

Area under the curve

Number of Occurrences

Compressive Strength

Mean, µ


34.1%

13.6%

What is standard deviation? It’s the average amount a number varies from the mean value in a series of numbers (compression test results). The total area under the curve is 100% which is why the PWL cannot be greater than 100. How does standard deviation affect the shape of the curve? The smaller the standard deviation the steeper the curve will be. The larger it is, the flatter the curve will be. Figure 3

One Standard Deviation

2.1%


How are WDOT incentive/disincentive amounts calculated on QMP Structure projects? The following excerpt is from the QMP Structures Special Provision.

How is my cylinder strength data reported to WDOT?

2012 Std. Spec. 715.5.3 Structures


How are WDOT incentive/disincentive amounts calculated on QMP Pavement projects? The following excerpt is from the QMP Pavement Special Provision. 2012 Std. Spec. 715.5.2 Pavements


Calculation of Mean and Standard Deviation: Acceptance of each lot of ready-mixed concrete for compressive strength shall be based on the percentage of material within specification limits (PWL). The PWL method considers the variability (standard deviation) as well as the average value (mean) of the test results. If a material with high variability is produced, then a higher average strength must be maintained in order to achieve a PWL that will produce incentive pay. The lower specification limit for compressive strength for each grade of concrete shall be as specified in the special provisions for the project. The PWL shall be determined using the MRS software. Consideration will be made for small lots with four or fewer tests; see the modified procedure as specified in the QMP Special Provisions for the project. These calculations shall not include compressive strength test results of cylinders fabricated from concrete material documented to have air content less than the lower control limit. a. Assign the sampling locations within the lot in accordance with the requirements of

the specification. b. Take a test sample at each location, cast two cylinders, cure and test the cylinders

in accordance with the requirements of the specification. Calculate and report all compressive strength test results in units of pounds per square inch.

The MRS software will make the following calculations. However, they are outlined below if

you wish to perform them. c. Calculate the average compressive strength of the two cylinders to represent the

compressive strength for that test. d. Calculate the mean (average) compressive strength of all tests within the lot by

use of the following formula:

X = C1 + C2 + C3 + … + Cn

n

Where: X = mean compressive strength for lot C = compressive strength for each test

n = number of tests in lot e. Calculate the standard deviation for the lot by use of the following formula:

Sn = (C1 – X)2 + (C2 – X)2 + (C3 – X)2 + … + (Cn – X)2

(n – 1)

Where : Sn = standard deviation for lot C = compressive strength for each test

X = mean compressive strength for lot n = number of tests in lot

TOPIC K: Latest Quality Management Program Specification K-0

DISCLAIMER: Continuing changes in conditions, construction materials, and construction technologies require changes in specifications. This specification was current when printed. Effort is made to keep this training manual as up to date as possible. Refer to your specific contract documents to insure contract compliance.

TOPIC K – QMP Concrete Pavement K-1

EXCERPT FROM: STANDARD SPECIFICATIONS FOR HIGHWAY AND STRUCTURE

CONSTRUCTON

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Standard Specifications

Help

Index Bid Items

Table of Contents

2016 Standard Specifications Changes since the 2015 edition are highlighted in red and a brief explanation of each change is provided both in the table of contents and adjacent to each revised passage.

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Effective with the December 2015 Letting 210 2016 Standard Specifications

(3) If the contractor offers to use an admixture that is essentially the same, with only minor differences in concentration, as another previously department-approved material, the department will require a certification stating it is essentially the same as the department-approved admixture, and that it contains no other admixture or chemical agent.

(4) The department will not require a certification for admixtures on the department's approved products list.

(5) Either before, or at any time during construction the engineer may require further testing on the admixture the contractor selects to determine its effect on the strength of the concrete. If tested, the 7-day compressive strength of the concrete sample made with enough of the admixture to produce the specified percent, +/- the specified tolerance percent, of entrained air in the plastic concrete shall not be less than 88 percent of the concrete strength made with the same materials, cement content, and consistency but without the admixture.

(6) Calculate the percentage reduction in strength from the average strength of at least five standard 6-inch by 12-inch cylinders of each type of concrete. Make and cure these specimens in the laboratory according to AASHTO T126 and test according to AASHTO T22. Determine the percentage of entrained air according to AASHTO T152.

(7) The department will reject admixtures failing to conform to the above requirements.

501.2.3 Retarding, Water Reducing, and Non-Chloride Accelerating Admixtures

501.2.3.1 General

(1) The engineer must approve all retarding and water reducing admixtures not on the department's approved products list before using them.

(2) The engineer will base approval of retarding and water reducing admixtures on tests made in the department's laboratory, or evaluation of results of tests made in a recognized laboratory as defined in 501.2.2(1). The manufacturer shall furnish test result data. Provide to the engineer a manufacturer's certification that the materials it is furnishing are essentially identical to those used in the performance testing.

(3) The department will maintain an approved products list for admixtures. The contractor may use admixtures included in the current approved products list, provided they produce the required properties in the concrete.

(4) Based on manufacturer-furnished data, the indicated relationships between temperature of mix, quantity of admixture, and time of initial set must satisfy the engineer.

(5) The contractor shall provide the laboratory and the engineer with manufacturer's data required for evaluations indicated above and for determining quantities of admixture for job conditions.

(6) Retarding and water reducing admixtures, as specified in this section, may or may not increase the amount of air entrained in the mix. If using admixtures in air-entrained concrete, ensure the concrete mix air content is within the range specified for air-entrained concrete under 501.3.2.4.

501.2.3.2 Retarding Admixtures

(1) All admixtures used to retard concrete setting as specified for set retarder under 501.3.2.4.3 shall conform to AASHTO M194, type D.

501.2.3.3 Water Reducing Admixtures

(1) If using water-reducing admixtures in concrete, conform to AASHTO M194, type A or type D, except that if adding a retarding admixture as specified for set retarder under 501.3.2.4.3, do not use type A.

501.2.3.4 Non-Chloride Accelerating Admixtures

(1) Conform to AASHTO M194, type C or type E.

501.2.4 Water

501.2.4.1 General

(1) Use water with cement in concrete, mortar, neat cement paste, or wash, and in other cement mixing operations conforming to 501.2.4.

501.2.4.2 Requirements

(1) The contractor may use drinking water from municipal water supplies for cement, except the engineer may test this water for compliance with the requirements specified below.

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(2) Water from other sources shall comply with the following: Acidity, maximum amount of 0.1N NaOH to neutralize 200 mL of water ............................................................ 2 mL

Alkalinity, maximum amount of 0.1N HCL to neutralize 200 mL of water ......................................................... 15 mL

Maximum sulphate (S04) ........................................................................................................................ 0.05 percent

Maximum chloride ................................................................................................................................... 0.10 percent

Maximum total solids:

Organic ................................................................................................................................................... 0.04 percent

Inorganic ................................................................................................................................................. 0.15 percent

(3) Use water that is not brackish and is clean and free of injurious amounts of sugar, oil, or other deleterious substances.

(4) Use water that causes no indication of unsoundness, no significant change in the time of setting, and varies no more than 10 percent in the strength of standard 1:3 mortar briquettes from strengths obtained with mixtures containing distilled water and the same cement and sand.

501.2.4.3 Sampling and Testing

(1) Submit samples that each consist of at least 2 quarts of water, obtained and shipped in clean plastic or glass containers, carefully packed and labeled. The engineer will supervise sampling. Test according to AASHTO T26.

501.2.4.4 Source

(1) Do not use water from shallow, muddy, or marshy sources. The contractor shall not use water from suspected sources until the engineer tests and approves it. If supply sources are relatively shallow, enclose the suction pipe intake to keep out silt, mud, grass, and other foreign materials. Position the suction pipe to provide at least 2 feet of water beneath the pipe intake.

501.2.5 Aggregates

501.2.5.1 General

(1) Furnish material conforming to the individual component requirements of 501.2.5.3 for fine aggregates and 501.2.5.4 for coarse aggregates except as follows:

1. If testing for gradation during concrete production, the department will accept material based on the combined properties as batched. The department will determine combined values and combined spec limits for both size and deleterious substances mathematically. The department will use the actual batch percentages for component aggregates in this calculation.

2. If the contractor is using a QMP paving or structures mix for other work on the project, the department will accept the aggregate for the affected mixes as specified in the applicable QMP provisions.

(2) The engineer may prohibit using aggregates from any source, plant, pit, quarry, or deposit if the character of the material or method of operation makes it unlikely to furnish aggregates conforming to specified requirements; or from deposits or formations known to produce unsound materials.

(3) Before use, furnish samples of materials from previously untested sources and from previously tested sources if the engineer requires.

(4) If procuring aggregates from pits or quarries, conform to 104.9 for final cleanup.

501.2.5.2 Definitions

(1) Use the definitions in 301.2, 450.2.1, and the following:

Fine aggregates Those aggregates that entirely pass the 3/8-inch sieve, almost entirely pass the No. 4 sieve and are predominantly retained on the No. 200 sieve.

Coarse aggregates Those aggregates predominantly retained on the No. 4 sieve.

501.2.5.3 Fine Aggregates

(1) Fine aggregate consists of a combination of sand with fine gravel, crushed gravel, or crushed stone consisting of hard, strong, durable particles.

501.2.5.3.1 Deleterious Substances

(1) Do not exceed the following percentages: SUBSTANCE PERCENT BY WEIGHT

Material passing the No. 200 sieve ..................................................................................................................... 3.5[1]

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Section 701 General QMP Requirements

701.1 Description

(1) This section describes contractor responsibilities common to QMP's under part 7 including quality control plans; personnel and laboratory certification; quality control testing; and data submission and record keeping. This section also describes department responsibilities, common to all QMP's under part 7, for verification and quality assurance testing. Exceptions and additional requirements under the QMP program are specified under specific QMP provisions.

701.2 Quality Control Program

701.2.1 General

(1) Provide and maintain a quality control program, defined as all activities and documentation of the following:

1. Mix and gradation design.

2. Control and inspection of production and placement processes.

3. Material sampling, testing, and correction of in-place work.

(2) CMM chapter 8 provides additional detailed guidance for QMP work and describes required sampling and testing procedures. The contractor may obtain the CMM from the department’s web site at:

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

(3) The department’s materials reporting system (MRS) software allows contractors to submit selected data to the department electronically, estimate pay adjustments, and print reports. Qualified personnel may obtain MRS software at:

http://www.atwoodsystems.com/iibv2/default.cfm

701.2.2 Quality Control Plan

(1) Submit a comprehensive written quality control plan and construct the project as that plan provides. Submit the plan to the engineer no later than 10 business days before producing or placing material. Do not change the quality control plan without the engineer’s review. Update with changes as they become effective. Provide a current plan to the engineer and post in each contractor laboratory before producing material and as changes are adopted.

(2) Ensure that the quality control plan includes the following elements:

1. Organizational chart including names, telephone numbers, current certifications, and roles and responsibilitiesof quality control personnel.

2. Process for disseminating quality control and corrective actions information to appropriate persons. Include alist of recipients, the communication means used, and action time frames.

3. Locations of QC laboratories.

4. Material sources.

5. Initial and routine equipment checks and documentation.

6. Frequency of contractor quality control testing.

7. Process control testing the contractor intends to perform, and associated control charts or otherdocumentation the contractor will make available to the department.

8. Procedures for documenting the locations of yielding foundation layers.

(3) The contractor may submit an abbreviated quality control plan consisting of only item 1 of 701.2.2(2) as follows:

- If the various quantities subject to QMP testing under the contract are less than the amount of material defined as a small quantity under the specific contract QMP provisions. The contractor may choose to increase testing frequency without submitting a comprehensive quality control plan.

- If specific contract QMP provisions allow an abbreviated quality control plan. For contracts containing multiple QMP provisions, the contractor can submit an abbreviated quality control plan for a portion of the work or integrate that work into a comprehensive plan required under the contract.

701.2.3 Personnel Certification

(1) Have HTCP-certified personnel perform sampling, testing, and documentation as follows:


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TABLE 701-1 PERSONNEL CERTIFICATION REQUIREMENTS

REQUIRED CERTIFICATION LEVEL SAMPLING OR TESTING ROLES

PCC Technician I PCC Assistant Certified Technician (ACT-PCC)

Sampling fresh concrete Air content, slump, and temperature testing Fabrication and curing of concrete strength specimens

Concrete Strength Tester CST Assistant Certified Technician (ACT-CST)

Concrete strength testing

Aggregate Technician IPP Aggregate Sampling Technician Aggregate Assistant Certificate Technician (ACT-AGG)

Aggregate sampling

Aggregate Technician IPP Aggregate Assistant Certified Technician (ACT-AGG)

Gradation, P 200, and moisture content testing

(2) A certified technician must coordinate and take responsibility for the work an ACT performs. Have a certified technician ensure that sampling and testing is performed correctly, analyze test results, and post resulting data. No more than one ACT can work under a single certified technician.

701.2.4 Laboratory Certification

(1) Ensure that contractor portable and fixed laboratories as well as commercial laboratories performing testing under the contract are qualified to perform the work in question. Obtain information on the Wisconsin laboratory qualification program from the department’s web site at:

http://wisconsindot.gov/Pages/doing-bus/eng-consultants/cnslt-rsrces/tools/appr-prod/qual-labs.aspx

701.2.5 Equipment

(1) Furnish the necessary equipment and supplies for performing quality control testing. The engineer may inspect the measuring and testing devices to confirm both calibration and condition. Calibrate testing equipment according to CMM 8-30 and maintain a calibration record at the laboratory.

701.2.6 Documentation

(1) Document all observations, inspection records, and process adjustments daily. Submit test results to the department's project materials coordinator on the same day they become available.

(2) Use forms provided in CMM chapter 8. Note other information in a permanent field record and as a part of process control documentation enumerated in the contractor's quality control plan. Enter data into the applicable MRS software within 5 business days after results are available.

(3) Submit final testing records and other documentation to the engineer electronically within 10 business days after all contract-required information becomes available. The engineer may allow submission of scanned copies of hand-written documentation.

701.3 Contractor Testing

(1) Perform contract required QC tests for samples randomly located according to CMM 8-30. Also perform other tests as necessary to control production and construction processes, and additional testing enumerated in the contractor's quality control plan or that the engineer directs. Use test methods as follows:


http://wisconsindot.gov/rdwy/cmm/cm-08-30.pdf#cm8-30

http://wisconsindot.gov/rdwy/cmm/cm-08-00toc.pdf#0


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TABLE 701-2 TESTING STANDARDS

TEST TEST STANDARD Washed P 200 analysis AASHTO T11[1]

Sieve analysis of fine and coarse aggregate AASHTO T27[1]

Aggregate moisture AASHTO T255[1]

Sampling freshly mixed concrete AASHTO R60

Air content of fresh concrete AASHTO T152[2]

Concrete slump AASHTO T119[2]

Concrete temperature ASTM C1064

Concrete compressive strength AASHTO T22

Making and curing concrete cylinders AASHTO T23

Standard moist curing for concrete cylinders AASHTO M201

[1] As modified in CMM 8-60.

[2] As modified in CMM 8-70.

(2) Notify the engineer when an individual test exceeds a spec limit. Material from the first out-of-spec test up to, but not including, material from the first subsequent in-spec test is nonconforming. The department may reject or otherwise determine the final disposition of nonconforming material as specified in 106.5.

(3) The department may periodically observe contractor sampling and testing, and direct additional contractor sampling and testing for department evaluation.

701.4 Department Testing

701.4.1 General

(1) The department conducts verification testing to validate product quality and independent assurance testing to evaluate sampling and testing. The department will use the same sampling and testing methods required for contractor testing under 701.3. The department will provide the contractor with a list of names and telephone numbers of project verification and independent assurance personnel.

(2) The department will provide test results to the contractor within 2 business days after the department obtains the sample, or in the case of long term testing, within 2 business days after results are available.

(3) Correct department-identified deficiencies. If the contractor fails to correct deficiencies or resolve discrepancies, the engineer may suspend production. Resolve disputes as specified in 106.3.4.3.5.

701.4.2 Verification Testing

(1) The department will have an HTCP-certified technician, or ACT working under a certified technician, perform QV sampling and testing. Department QV testing personnel must meet the same certification level requirements specified for contractor testing personnel for each test being verified. The department will notify the contractor before sampling so the contractor can observe QV sampling.

(2) The department will sample randomly at locations independent of the contractor’s QC tests and use separate equipment and laboratories. The department will conduct a minimum of one verification test for each 5 contractor QC tests unless specific QMP provisions specify otherwise.

(3) If verification tests conform to specifications, no further action is required. If verification tests do not conform to specifications, the department will notify the contractor immediately. The engineer and contractor will jointly investigate nonconforming test results. The investigation may include additional testing as well as review and observation of both department and contractor sampling and testing procedures, equipment, and other documented test results. Both parties will document investigative work.

701.4.3 Independent Assurance Testing

(1) The department performs independent assurance testing to evaluate department verification and contractor’s QC sampling and testing including personnel qualifications, procedures, and equipment. The department will perform independent assurance reviews according to the department’s independent assurance program, which may include one or more of the following:

1. Split sample testing.

2. Proficiency sample testing.

3. Witnessing sampling and testing.




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4. Test equipment calibration checks.

5. Reviewing contract-required data and available contractor process control information.

6. Requesting that testing personnel perform additional sampling and testing.

701.5 Payment

(1) Costs for sampling, testing, and documentation under part 7 are incidental to the work. If the contractor fails to perform work required under the contract QMP provisions, the department may reduce the contractor’s pay. The department will administer pay reductions under the Non-performance of QMP administrative item.

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Section 710 General Concrete QMP

710.1 Description

(1) This section describes contractor QC testing requirements common to all concrete classes under part 7. Exceptions and additional requirements for concrete testing are specified in:

- 715 for class I concrete used in structures and pavement.

- 716 for class II and class III concrete used in ancillary applications.

710.2 Small Quantities

(1) For contracts with only small quantities of material subject to testing, as defined under specific contract QMP provisions, modify the requirements of 710 as follows:

1. The contractor may submit an abbreviated quality control plan as allowed in 701.2.2.

2. The engineer may accept aggregate based on documented previous testing.

710.3 Certification Requirements

(1) Have a certified PCC technician I, or ACT-PCC working under a certified technician, present at the project site, prepared and equipped to perform required sampling and testing whenever placing concrete.

710.4 Concrete Mixes

(1) The contractor is responsible for mix performance.

(2) At least 3 business days before producing concrete, provide documentation ensuring that materials conform to 501 unless the engineer allows or specific QMP provisions provide otherwise. Include the following:

1. For mixes: quantities per cubic yard expressed as SSD weights and net water, water to cementitious material ratio, and air content.

2. For cementitious materials and admixtures: type, brand, and source.

3. For aggregates: absorption, SSD bulk specific gravity, wear, soundness, freeze thaw test results if required, and air correction factor. Also include proposed gradation, including P200, limits if using a combined gradation as allowed under 715.2.2.

(3) Do not use any chemical admixtures, other than air-entraining agents, water reducers, or water reducing retarders from the department’s approved products list, without conforming to the following:

- Obtain the engineer’s approval in advance.

- Document, by independent laboratory test reports, that the admixture conforms to AASHTO M194.

(4) Document mix adjustments daily during concrete production.

(5) Prepare and submit modifications to a concrete mix to the engineer for approval before using that modified mix. Modifications requiring the engineer’s approval include changes in:

1. Source of any material.

2. Amounts of cementitious materials.

3. Adjustment of fine to total aggregate greater than ±3 percent by weight.

4. Addition or deletion of admixtures. Minor admixture dosage adjustments required to maintain air content or slump do not require engineer review or approval.

(6) When the department requires or allows high early strength concrete, use type III cement or one of the following:

- Add at least 95 pounds but no more than 280 pounds of cement per cubic yard to a previously accepted mix along with enough water to maintain workability without raising the w/cm.

- Substitute regular grade C for grade A or A2 high early strength concrete.

- Substitute regular grade A for grade B high early strength concrete.

710.5 Sampling and Testing

710.5.1 Sampling

(1) Sample fresh concrete at the point of placement.

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710.5.2 Slump

(1) Provide material conforming to the slumps specified in 501.3.7.1. The contractor need not test slump for concrete placed by slip-form methods unless the engineer requests. For other placement methods, test slump whenever an air content test is performed, cylinders are made, and as the engineer directs.

710.5.3 Air Content

(1) Provide material conforming to the air contents specified in 501.3.2.4.2. On each day of production, test at start-up and as frequently as practicable until concrete is conforming and concrete production is under control. Subsequently, test at the QC testing frequency specified in specific contract QMP provisions and as the engineer directs.

(2) If an individual air test is outside the spec limits, notify the engineer and test as often as practicable on subsequent loads until the air content is conforming.

710.5.4 Concrete Temperature

(1) Measure concrete temperature of the same sample used for air content testing and report the results along with the air content.

710.5.5 Compressive Strength

(1) Cast all 6-inch by 12-inch cylinders in a set from the same sample. Do not cast more than one set of cylinders from a single truckload of concrete. Mark each cylinder to identify the lot and sublot or location on the project it represents.

(2) Provide facilities for initial curing. For up to 48 hours after casting, maintain the temperature adjacent to the specimens in the range of 60 to 80 F and prevent moisture loss. Between 24 and 48 hours after casting, transport the specimens to a department-qualified laboratory for standard curing until testing at 28 days.

(3) Determine the 28-day compressive strength of each cylinder in psi. Test each cylinder to failure. Use a compression machine that automatically records the date, time, rate of loading, and maximum load of each cylinder. Provide a printout of this information for each cylinder tested.

710.5.6 Aggregate Testing

710.5.6.1 General

(1) Test each stockpile for each component aggregate during aggregate production or when building stockpiles at the concrete production location. If aggregate was stockpiled before the contract, and test records from production or stockpiling are not available or not acceptable to the engineer, test during concrete production.

(2) For testing performed during aggregate production or stockpiling, conform to the individual gradation limits for the coarse and fine aggregate fractions as specified in the contractor's quality control plan. For testing performed during concrete production, conform to combined gradation limits submitted in the contractor's quality control plan.

710.5.6.2 Gradation Testing During Aggregate Production or Stockpiling

(1) Determine the complete gradation, including P200, using a washed analysis for both fine and coarse aggregates. Test each stockpile for each component aggregate during aggregate production or stockpiling as follows:

TABLE 710-1 AGGREGATE PRODUCTION AND STOCKPILING GRADATION TESTING FREQUENCY

DAILY AGGREGATE PRODUCTION MINIMUM FREQUENCY PER STOCKPILE 1000 tons or less One test per cumulative total of 1000 tons

more than 1000 tons through 2000 tons Two tests per day

more than 2000 tons Three tests per day

(2) In addition to the testing performed during aggregate production or stockpiling, determine the combined P200 during concrete production. Ensure that the combined P200 is 2.3 percent or less. Use a washed analysis for both fine and coarse aggregates. Randomly, test at least once for each 50 cubic yards of concrete. For daily production greater than 50 cubic yards, one test per day is sufficient for constant mix conditions. The engineer may allow testing to be reduced to a minimum of once per 5 days of concrete production after 5 consecutive tests show that the combined P200 is less than or equal to 1.8 percent.

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710.5.6.3 Gradation Testing During Concrete Production

(1) Determine the complete gradation, including P200, using a washed analysis for both fine and coarse aggregates. Test each stockpile for each component aggregate as follows:

TABLE 710-2 CONCRETE PRODUCTION GRADATION TESTING FREQUENCY

DAILY CONCRETE PRODUCTION MINIMUM FREQUENCY PER STOCKPILE 250 cubic yards or less One test per cumulative total of 250 cubic yards

more than 250 cubic yards through 1000 cubic yards One test per day

more than 1000 cubic yards Two tests per day

(2) Report results for the 1 1/2", 1", 3/4", 1/2", 3/8", #4, #8, #16, #30, #50, #100, and #200 sieves.

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Section 715 QMP Concrete Pavement and Structures

715.1 Description

(1) This section describes contractor mix design and testing requirements for class I concrete used in concrete pavement, and concrete structures.

715.1.1 Quality Control Program

715.1.1.1 General

(1) Conform to the general requirements under 701 and 710 as well as the additional specific contract QMP provisions for class I concrete specified here in section 715. The department defines class I concrete as cast-n-place concrete used in pavement or structure applications where all of the following apply:

- Mix design requires review by the engineer.

- The contract defines spec limits for strength.

- The contractor may earn statistically based incentives for superior concrete strength. [1]

[1] HES and SHES concrete are not eligible for 28-day strength incentives.

715.1.1.2 Small Quantities

(1) The department defines small quantities of class I concrete, subject to the reduced requirements under 710.2, as follows:

- Less than 150 cubic yards of structure concrete placed under a single bid item.

- Less than 2500 cubic yards of slip-formed pavement placed using a single mix design.

- Less than 1000 cubic yards of non-slip-formed pavement placed using a single mix design.

715.1.1.3 Pre-Pour Meetings for Structure Concrete

(1) Arrange at least two pre-pour meetings to discuss concrete placement. Discuss the placement schedule, personnel roles and responsibilities, testing and quality control, and how test results will be communicated. Schedule the first meeting before placing any concrete and the second before placing any bridge deck concrete. Ensure that representatives from all parties involved with concrete work, including contractor, sub-contractor, ready-mix supplier, testers, and the project manager, attend these meetings.

715.1.1.4 Quality Control Plan

(1) If a comprehensive quality control plan is required under 701.2.2, submit a plan conforming to 701.2.2 and include additional concrete mix information as follows:

1. Preliminary concrete mix information including proposed production facilities and sources of materials as well as the name, title, and phone number of the person developing the mix design.

2. Proposed individual and combined aggregate gradation limits.

3. Proposed methods for monitoring and recording batch weights.

715.2 Materials

715.2.1 General

(1) Determine mixes for class I concrete used under the contract using one or more of the following methods:

- Have a HTCP-certified PCC technician II develop new concrete mixes qualified based on the results of mix development tests performed by a department-qualified laboratory.

- Submit previously-used department-approved mixes qualified based on field performance.

(2) The contractor need not provide separate laboratory mix designs for high early strength concrete nor provide routine 28-day compressive strength tests during placement for high early strength concrete.

(3) For lab-qualified or field-qualified mixes, in addition to the mix information required under 710.4, submit 2 copies of a concrete mix report at least 3 business days before producing concrete. For lab-qualified mixes, include strength data, test dates, and the name and location of the laboratory that performed mix development testing. For field-qualified mixes, include historical data that demonstrate acceptable strength and field performance.

(4) Ensure that the concrete mix report includes a cover sheet with signature blocks for both the mix developer and the engineer. Have the mix developer sign and date each copy attesting that all information in the report is accurate. The engineer will sign and date each copy of the report. The engineer’s signature verifies that the engineer had the opportunity to review the mix report, to check that it







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meets the concrete mix requirements, and to comment. The engineer will return a signed copy to the contractor within 3 business days of receiving the report.

715.2.2 Combined Aggregate Gradation

(1) Ensure that the combined aggregate gradation conforms to the following, expressed as weight percentages of the total aggregate:

1. One hundred percent passes the 2-inch sieve.

2. The percent passing the 1-inch sieve is less than or equal to 89. The engineer may waive this requirement for one or more of the following:

- Clear spacing between reinforcing bars is less than 2 inches.

- The contractor provides an engineer-approved optimized gradation analysis.

3. The percent passing the No. 4 sieve is less than or equal to 42, except if the coarse aggregate is completely composed of crushed stone, up to 47 percent may pass the No. 4 sieve. For pavement, coarse aggregate may be completely composed of recycled concrete, in which case up to 47 percent may pass the No. 4 sieve.

4. The percent passing the No. 200 sieve is less than or equal to 2.3 percent.

(2) Submit proposed combined gradation limits and target individual gradations along with the mix information required under 710.4.

715.2.3 Class I Concrete Mixes

715.2.3.1 Pavements

(1) Use at least 5 pairs of cylinders to demonstrate the compressive strength of a mix design. Use either laboratory strength data for new mixes or field strength data for established mixes. Demonstrate that the 28-day compressive strength of the proposed mix will equal or exceed the 85 percent within limits criterion specified in 715.5.2.

(2) Provide a minimum cement content of 565 pounds per cubic yard, except if using type I, IL, or III cement in a mix where the geologic composition of the coarse aggregate is primarily igneous or metamorphic materials, provide a minimum cement content of 660 pounds per cubic yard.

(3) The contractor may use class C fly ash or grade 100 or 120 slag as a partial replacement for cement. For binary mixes use up to 30% fly ash or slag, except for slip-formed work the contractor may use up to 50% slag. For ternary mixes use up to 30% fly ash plus slag in combination. Replacement values are in percent by weight of the total cementitious material in the mix.

(4) Ensure that the target ratio of net water to cementitious material for the submitted mix design does not exceed 0.42 by weight. Include free water on the aggregate surface but do not include water absorbed within aggregate particles.

(5) Do not use chloride based accelerators in mixes for new construction.

715.2.3.2 Structures

(1) Qualify compressive strength according to ACI Code 318 chapter 5 subsections 5.3.1 through 5.3.3 and 5.5. Use either laboratory strength data for new mixes or field strength data for established mixes. Demonstrate that the 28-day compressive strength of the proposed mix will equal or exceed the 90 percent within limits criterion specified in 715.5.3.

Revise 715.2.3(2) to allow type IT ternary blended cements.

(2) Provide a mix grade containing fly ash (A-FA), slag (A-S), both fly ash and slag (A-T), or blended cement (A-IP, A-IS, or A-IT) Ensure that the cementitious content equals or exceeds 565 pounds per cubic yard. Unless the engineer approves otherwise in writing, conform to one of the following:

1. Use class C fly ash or grade 100 or 120 slag as a partial replacement for cement. For binary mixes use 15% to 30% fly ash or 20% to 30% slag. For ternary mixes use 15% to 30% fly ash plus slag in combination. Replacement values are in percent by weight of the total cementitious material in the mix.

2. Use a type IP, IS, or IT blended cement.

(3) Ensure that the target ratio of net water to cementitious material (w/cm) for the submitted mix design does not exceed 0.45 by weight. Include free water on the aggregate surface but do not include water absorbed within aggregate particles. Control the w/cm ratio throughout production by adjusting batch weights for changes in the aggregate moisture as required under 715.3.3.2.

(4) Do not use mixes containing accelerators, except the contractor may use mixes containing non-chloride accelerators in substructure elements.


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715.3 Testing and Acceptance

715.3.1 Class I Concrete Testing

715.3.1.1 General

(1) Provide slump, air content, concrete temperature and compressive strength test results as specified in 710.5. Provide a battery of QC tests, consisting of results for each specified property, using a single sample randomly located within each sublot. Cast three cylinders for strength evaluation.

(2) If a sublot random test location falls within a mainline pavement gap, relocate the test to a different location within the sublot.

715.3.1.2 Lot and Sublot Definition

715.3.1.2.1 General

(1) Designate the location and size of all lots before placing concrete. Ensure that no lot contains concrete of more than one mix design, as defined in 715.3.1, or more than one placement method, defined as either slip-formed, not slip-formed, or placed under water.

(2) Lots and sublots include ancillary concrete placed integrally with the class I concrete.

715.3.1.2.2 Lots by Lane-Feet

(1) The contractor may designate slip-formed pavement lots and sublots conforming to the following:

- Lots and sublots are one paving pass wide and may include one or more travel lanes, integrally placed shoulders, integrally placed ancillary concrete, and pavement gaps regardless of mix design and placement method.

- Sublots are 1000 feet long for single-lane and 500 feet long for two-lane paving. Align sublot limits with ride segment limits defined in the special provisions. Adjust terminal sublot lengths to match the project length or, for staged construction, the stage length. Ensure that sublot limits match for adjacent paving passes. Pavement gaps do not affect the location of sublot limits.

- Create lots by grouping 4 to 8 adjacent sublots matching lots created for adjacent paving passes.

(2) If a sublot random test location falls in a pavement gap, test at a different random location within that sublot.

715.3.1.2.3 Lots by Cubic Yard

(1) Define standard lots and sublots conforming to the following:

- Do not designate more than one sublot per truckload of concrete.

- Lots for structures are a maximum of 500 cubic yards divided into approximately equal 50-cubic-yard or smaller sublots.

- Lots for pavement are a maximum of 2000 cubic yards divided into approximately equal 250-cubic-yard or smaller sublots.

(2) The contractor may designate lots smaller than standard sized. An undersized lot is eligible for incentive payment under 715.5 if the contractor defines 4 or more sublots for that lot.

715.3.1.3 Department Verification Testing

(1) The department will perform verification testing as specified in 701.4.2 except as follows:

- Air content, slump, and temperature: a minimum of 1 verification test per lot.

- Compressive strength: a minimum of 1 verification test per lot.

715.3.2 Strength Evaluation

715.3.2.1 General

(1) The department will make pay adjustments for compressive strength on a lot-by-lot basis using the compressive strength of contractor QC cylinders. The department will accept or reject concrete on a sublot-by-sublot basis using core strength. Perform coring and testing, fill core holes with an engineer-approved non-shrink grout, and provide traffic control during coring.

(2) Randomly select 2 QC cylinders to test at 28 days for percent within limits (PWL). Compare the strengths of the 2 randomly selected QC cylinders and determine the 28-day sublot average strength as follows:

- If the lower strength divided by the higher strength is 0.9 or more, average the 2 QC cylinders.

- If the lower strength divided by the higher strength is less than 0.9, break one additional cylinder and average the 2 higher strength cylinders.



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715.3.2.2 Removal and Replacement

715.3.2.2.1 Pavement

(1) If a sublot strength is less than 2500 psi, the department may direct the contractor to core that sublot to determine its structural adequacy and whether to direct removal. Cut and test cores according to AASHTO T24 as and where the engineer directs. Have an HTCP-certified PCC technician I perform or observe the coring.

(2) The sublot pavement is conforming if the compressive strengths of all cores from the sublot are 2500 psi or greater or the engineer does not require coring.

(3) The sublot pavement is nonconforming if the compressive strengths of any core from the sublot is less than 2500 psi. The department may direct removal and replacement or otherwise determine the final disposition of nonconforming material as specified in 106.5.

715.3.2.2.2 Structures

(1) The department will evaluate the sublot for possible removal and replacement if the 28-day sublot average strength is lower than f’c minus 500 psi. The value of f’c is the design stress the plans show. The department may assess further strength price reductions or require removal and replacement only after coring the sublot.

(2) The engineer may initially evaluate the sublot strength using a non-destructive method. Based on the results of non-destructive testing, the department may accept the sublot at the previously determined pay for the lot, or direct the contractor to core the sublot.

(3) If the engineer directs coring, obtain three cores from the sublot in question. Have an HTCP-certified PCC technician I perform or observe core sampling according to AASHTO T24. Determine core locations, subject to the engineer’s approval, that do not interfere with structural steel.

(4) Have an independent consultant test cores according to AASHTO T24.

(5) If the 3-core average is greater than or equal to 85% of f’c, and no individual core is less than 75% of f’c, the engineer will accept the sublot at the previously determined pay for the lot. If the 3-core average is less than 85% of f’c, or an individual core is less than 75% of f’c, the engineer may require the contractor to remove and replace the sublot or assess a price reduction of $35 per cubic yard or more.

715.3.3 Aggregate

715.3.3.1 General

(1) Except as allowed for small quantities in 710.2, provide aggregate test results conforming to 710.5.6.

715.3.3.2 Structures

(1) In addition to the aggregate testing required under 710.5.6, determine the fine and coarse aggregate moisture content for each sample used to test the percent passing the No. 200 sieve.

(2) Calculate target batch weights for each mix when production of that mix begins. Whenever the moisture content of the fine or coarse aggregate changes by more than 0.5 percent, adjust the batch weights to maintain the design w/cm ratio.

715.4 Measurement

(1) The department will measure Incentive Strength Concrete Pavement and Incentive Strength Concrete Structures by the dollar, calculated as specified in 715.5.

715.5 Payment

715.5.1 General

(1) The department will pay incentive for compressive strength under the following bid items:

ITEM NUMBER DESCRIPTION UNIT

715.0415 Incentive Strength Concrete Pavement DOL

715.0502 Incentive Strength Concrete Structures DOL

(2) Incentive payment may be more or less than the amount the schedule of items shows.

(3) The department will administer disincentives for compressive strength under the Disincentive Strength Concrete Pavement and the Disincentive Strength Concrete Structures administrative items.

(4) The department will adjust pay for each lot using PWL of the 28-day sublot average strengths for that lot. The department will measure PWL relative to the lower specification limit of 3700 psi for pavements and





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4000 psi for structures. The department will not pay a strength incentive for concrete that is nonconforming in another specified property, for ancillary concrete accepted based on tests of class I concrete, or for high early strength concrete unless placed in pavement gaps as allowed under 715.3.1.2.1.

(5) Submit strength results to the department electronically using the MRS software. The department will validate contractor data before determining pay adjustments.

(6) All coring and testing costs under 715.3.2.2 including filling core holes and providing traffic control during coring are incidental to the contract.

715.5.2 Pavements

(1) The department will adjust pay for each lot using equation “QMP 3.01” as follows: Percent within Limits (PWL) Pay Adjustment (dollars per square yard)

≥ 95 to 100 (0.1 x PWL) - 9.5

≥ 85 to < 95 0

≥ 30 to < 85 (1.5/55 x PWL) - 127.5/55

< 30 -1.50

(2) The department will not pay incentive if the lot standard deviation is greater than 400 psi.

(3) For lots with a full battery of QC tests at less than 4 locations, there is no incentive but the department will assess a disincentive based on the individual sublot average strengths. The department will reduce pay for sublots with an average strength below 3700 psi by $1.50 per square yard.

(4) For integral shoulder pavement and pavement gaps accepted using tests from the adjacent travel lane, The department will adjust pay using strength results of the travel lane for integrally placed concrete shoulders and pavement gaps regardless of mix design and placement method, included in a lane-foot lot.

715.5.3 Structures

(1) The department will adjust pay for each lot using equation “QMP 2.01” as follows: Percent within Limits (PWL) Pay Adjustment (dollars per cubic yard)

≥ 99 to 100 10

≥ 90 to < 99 0

≥ 50 to < 90 (7/8 x PWL) – 78.75

< 50 -35

(2) The department will not pay incentive if the lot standard deviation is greater than 350 psi.

(3) For lots with less than 4 sublots, there is no incentive but the department will assess a disincentive based on the individual sublot average strengths. The department will reduce pay for sublots with an average strength below 4000 psi by $35 per cubic yard.

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Section 716 QMP Ancillary Concrete

716.1 Description

(1) This section describes contractor mix selection and testing requirements for class II and class III concrete.

716.1.1 Quality Control Program

716.1.1.1 General

(1) Conform to the general requirements under 701 and 710 as modified here in section 716 for class II and class III concrete defined as follows:

- Class II: ancillary concrete the department accepts based on field testing during placement.

- Class III: ancillary concrete the department accepts by certification.

716.1.1.2 Quality Control Plan

(1) The contractor need only submit an abbreviated quality control plan as defined in 701.2.2.

716.2 Materials

716.2.1 Class II Concrete

(1) Determine mixes for class II concrete used under the contract according to 501. If a grade A mix is allowed under standard spec 501.3.1.3, the contractor may use a class I mix design approved under 715.2. Ancillary concrete placed integrally with mainline pavement is accepted using tests of class I concrete but not eligible for incentive payment under section 715.5. Document the locations and quantities of integral concrete and identify the class I sublot tests used for acceptance.

(2) Perform random QC testing at the following frequencies:

1. Test air content and slump a minimum of once per 100 cubic yards for each mix grade and placement method.

2. Cast one set of 2 cylinders per 200 cubic yards for each mix grade and placement method. Cast a minimum of one set of 2 cylinders per contract for each mix grade and placement method. Random 28-day compressive strength cylinders are not required for HES or SHES concrete.

3. For deck overlays, perform tests and cast cylinders once per 50 cubic yards of grade E concrete placed.

4. For concrete base and base patching, one set of tests and one set of cylinders per 250 cubic yards.

(3) Conform to the initial curing requirements under 710.5.5 except the contractor may extend initial curing for 72 hours before transporting the cylinders to a department-qualified laboratory.

(4) Test aggregate gradations, including P200, as specified in 710.5.6 at the frequency listed below which results in the least number of tests:

- A maximum of one test per day.

- A minimum of one test per 400 cubic yards of cumulative concrete placed.

Alternatively the engineer may accept aggregate based on documented previous testing.

(5) Department verification testing is optional for aggregate used in class II concrete.

716.2.2 Class III Concrete

(1) Acceptance of class III concrete is based on a certificate of compliance. Submit the certificate of compliance at least 3 business days before producing concrete along with the initial concrete mix documentation as required under 710.4(2).

(2) Contractor testing for the mix and mix aggregates is not required for the items contained within the certificate of compliance. Conform to 716.2.1 for items not contained within the certificate of compliance.

(3) Department verification testing is optional for class III concrete. Correct any deficiencies found during the QV testing.

716.3 (Vacant)

716.4 (Vacant)

716.5 (Vacant)










http://wisconsindot.gov/rdwy/stndspec/ss-07-10.pdf#ss710.4p2

TOPIC L: Record Keeping – Control Charts L-1


Control chart trends, corrective action examples, and project documents will be discussed thoroughly in this section.

Notes, Figures or Tables:

Benefits of Control Charts

Early Detection of Trouble

Decrease Variability

Establish Process Capability

Reduce Price Adjustment

Decrease Inspection Frequency

Basis for Altering Specification Limits

Permanent Record of Quality

Provide Basis for Acceptance

Instill Quality Awareness


L.1 Introduction

As discussed previously, control charts provide a means for the contractor to identify when corrections should be made in the process. When properly used, control charts can provide an early detection system for identifying potential trouble spots for the contractor. The WisDOT specifications define when the contractor must take actions. However, the prudent contractor and quality control staff will watch the data and trends and take corrective action as soon as test data confirms something is not right in the process.

Corrective actions may include inspecting laboratory equipment, inspecting plant or placement equipment, making adjustments in the process, changing materials, quantities, or equipment, or combinations of these actions. Corrective actions are required to always be documented, along with the resulting effects of the corrective action.

L.2 Corrective Action Triggers

The QMP specifications suggest the contractor consider corrective action when the running average trend is towards a warning limit. Corrective action is required when 2 consecutive running average points exceed a warning limit. In addition, most of the QMP specifications require action when an individual test result exceeds a control limit. The specification that is being used should be reviewed to determine when and what action is required for situations when test results exceed a specification limit and to assess the effectiveness of corrective action.

The matrices shown in Figures L-1 through L-3 summarize the actions necessary according to the QMP specifications. Notice that in addition to corrective actions the contractor must take, the PCCTEC-I may need to increase the frequency of sampling and testing in certain situations.


Figure L-1: Corrective Action Triggers – QMP Concrete Pavement*

Individual Test Point 4 Pt. Moving Average (Trend Line)

Approaching a warning limit

The contractor should consider corrective action.

Exceeds the warning limit

The air content test frequency must be doubled to 2 tests per sublot.

Perform one of these tests from the same concrete sample used for the QC strength cylinders. Select the second sample randomly from the half of the sublot not used for the QC strength cylinders.

Continue testing at increased frequency until an individual test point is above the lower warning limit and below the upper control limit.

When the running average first exceeds the warning limit, the contractor must notify the engineer.

When a second consecutive running average exceeds the warning limit, the contractor must discuss a course of corrective action with the engineer, and perform the corrective action.

If the corrective action improves the property in question such that the new running average, after 4 additional individual tests, is between the lower warning limit and upper control limit, the contractor may continue production.

Exceeds the control limit

The contractor must notify the engineer, and perform additional air content tests (non-random), as often as practicable on subsequent loads of material being delivered until the air content is inside the control limits.

Material from the load with the first test exceeding the control limit, continuing to but not including the load with the first subsequent test within the control limits, is nonconforming.

* Note: The information in the above tables is subject to change. Use the version of thespecification defined in the contract.


Figure L-2: Corrective Action Triggers – QMP Concrete Structures*

Individual Test Point 4 Pt. Moving Average (Trend Line)

Approaching a warning limit

The contractor should consider corrective action.


The air content test frequency must be doubled to 2 tests per sublot.

Perform one of these tests from the same concrete sample used for the QC strength cylinders. Select the second sample randomly from the half of the sublot not used for the QC strength cylinders.

Continue testing at increased frequency until an individual test point is above the lower warning limit and below the upper control limit.

When the running average first exceeds the warning limit, the contractor must notify the engineer.

When a second consecutive running average exceeds the warning limit, the contractor must discuss a course of corrective action with the engineer, and perform the corrective action.

If the corrective action improves the property in question such that the new running average, after 4 additional individual tests, is between the lower warning limit and upper control limit, the contractor may continue production.



Material from the load with the first test exceeding the control limit, continuing to but not including the load with the first subsequent test within the control limits, is nonconforming.



Figure L-3: Corrective Action Triggers – QMP Concrete Ancillary*

Individual Test Point


Double the air content test frequency if an individual air test falls outside the warning limits.

Continue testing at increased frequency until an individual test point is back within the warning band



Material from the load with the first test exceeding the control limit, continuing to but not including the load with the first subsequent test within the control limits, is nonconforming



Review Questions

RK.1. You are the PCCTEC-I responsible for the sampling and testing of concrete for a slip form paving project. Following are quality control charts representing the sequence of air content tests performed on the concrete. For each scenario, identify the condition(s) and the action(s) required, if any. (Solutions on Page L-9)

Contractor Acceptance (QC) Running average of 4 Verification (QV) Process control Independent Assurance (IA)

Figure RK.1.A

Condition(s):

Requirement(s):

What would need to be done if the contractor took action at this point?

Figure RK.1.B

Condition(s):

Requirement(s):

How long must the double frequency testing continue?



Figure RK.1.C

Condition(s):

Requirement(s):

Figure RK.1.D

Condition(s):

Requirement(s):

What must the QC technician do at this point?


RK.2. The following control charts are a continuation of the testing from question RK.1 and represent 3 different scenarios that could occur subsequent to test #12. Identify the condition(s) and requirement(s) for each scenario. (Solutions on Page L-10)


Figure RK.2.A

Condition(s):

Requirement(s):

If process control tests were performed after correction, how would they be handled here?

Figure RK.2.B

Condition(s):

Requirement(s):


Figure RK.2.C

Condition(s):

Requirement(s):

What else should the QC technician record?


SOLUTIONS TO QUESTION RK.1.

Figure RK.1.A Condition(s): The moving average is approaching the warning limit.

Requirement(s): The contractor should consider corrective action.

What would need to be done if the contractor took action at this point? Document the corrective action.

Figure RK.1.B Condition(s): An individual test point exceeds the warning limit.

Requirement(s): Air content test frequency shall be doubled to two tests per compressive strength sublot.

How long must the double frequency testing continue? Until an individual test point is above (not just on the line) the LWL and below the UCL.

Figure RK.1.C Condition(s): The moving average has exceeded the warning limit. Another individual test point exceeds the warning limit.

Requirement(s): The contractor shall notify the engineer. Double frequency air testing shall continue.

Figure RK.1.D Condition(s): A second moving average has exceeded the warning limit. Another individual test point exceeds the warning limit.

Requirement(s): The contractor shall discuss a course of corrective action with the engineer and perform the action.

What must the QC technician do at this point? Document the corrective action. Continue double frequency testing


SOLUTIONS TO QUESTION RK.2.

Figure RK.2.A Condition(s): Corrective action improved the condition such that the individual test results and the new running average are between the LWL and the UCL.

Requirement(s): Contractor may continue production. Double frequency testing ceased after the first test.

If process control tests were performed after correction, how would they be handled here? They are plotted with hollow dots as PC tests on chart.

Figure RK.2.B Condition(s): The first individual test after correction is in the warning band. Subsequent QC tests remain in the warning band.

Requirement(s): Double frequency testing would still continue after the first test subsequent to the correction. At the first moving average point, the contractor shall notify the engineer. At the second, the engineer and contractor shall discuss and perform corrective action.

Figure RK.2.C Condition(s): An individual test point exceeds the control limit.

Requirement(s): The contractor shall notify the engineer. Additional non-random air content tests shall be performed as often as practicable on subsequent loads of material being delivered until the air content is inside the control limits.

What else should the QC technician record? Identify the location (station or volume) where first truckload is outside of the control limits and the location (again by station or volume) where the first truckload is within the control limits.

Topic M: Worksheets M-1

0.45 Power Aggregate Gradation Chart (WS3014)

Moisture Content-P200-W/C Ratio Worksheet

Air Content Control Chart – QMP Pavement (WS5016)

Air Content Control Chart – QMP Structures (WS5017)

Ancillary Daily Report (WS5013)

Combination Aggregate Gradation HTCP version WS3012)

Summary of Combined Gradation & Specification (WS3012 pg 2)

Concrete Cylinder Test Data Card (dt1308)

Field Batch Weights for Concrete (dt2220)

Concrete Mix Design Cover Page (WS5014)

Concrete Pavement Thickness Log (Attachment 31)

Field test – Cylinder Fabrication Table (WS5018)

Individual % Retained Sieve Test Chart

P200 Control Chart

PCC Batch Plant Records (dt1926)

Running Average of 4 Worksheet (WS3015)

Placement Test Site Sample Locations (WS3013)

Air Content Control Chart - Pavement

TOPIC N: Concrete Curing N-1


CURING CONCRETE

Exposed slab surfaces are especially sensitive to curing as the top surface strength development can be reduced significantly when curing is defective.


The need for proper curing of concrete cannot be overemphasized.

Curing has a strong influence on the properties of hardened concrete, such as: • Durability • Strength • Water tightness • Abrasion resistance • Volume stability • Resistance to freezing and thawing • Deicer salts

Objectives of curing

Prevent (or replenish) the loss of moisture from concrete

Maintain a favorable concrete temperature

Allow enough time


Note: Figure 15-2, Page 303 shows the strength gain of concrete with age for different curing periods.


Proper Curing will contribute to: • Stronger concrete • More impermeable concrete • More stress resistance • More abrasion resistance • Resistance to freezing and thawing


Curing Methods and Materials Concrete can be kept moist (and in some cases at a favorable temperature) by three curing methods:

1. Maintain the presence of mixing water in the concrete during the early stages of hardening.

Methods include: - Ponding or immersion - Spraying of fogging - Saturated wet covering

Note: These methods also will cool and may be beneficial in hot weather. 2. Prevent loss of mixing water from the concrete by sealing the surface.

Methods include:

- Cover with plastic sheets - Apply membrane-forming curing compounds.

3. Methods to accelerate strength gain by supplying heat and additional

moisture to the concrete. Methods include: - Live steam - Heating coils - Electric form or rods



Ponding or Immersion

Conducted on flat surfaces, such as pavements and floors

Curing water should not be more than 20º F cooler than the concrete to prevent thermal stresses that could result in additional cracking.

Use caution – the water used for curing by ponding or immersion must be free of substances that will stain or discolor the concrete.

Spraying or Fogging

Continuous spraying or fogging with water is an excellent method as long as temperatures are above freezing.

Ordinary lawn sprinklers are effective spraying tools, although run-off may be a concern.

Soil-soaker hoses are also very useful on horizontal surfaces.

If spraying or fogging methods are used, they must be continuous to avoid wetting and drying cycles, which can cause surface-crazing or cracking.

Wet Coverings

Fabric coverings saturated with water may be used, such as burlap or other moisture-retaining fabrics. o The requirements for burlap cloths are covered in AASHTO M182. o The requirements for white burlap – polyethylene sheeting – are described in

ASTM C 171.

Caution: Burlap must be free of substances that may cause discoloration.

Wet, moisture-retaining, fabric coverings should be placed as soon as the concrete has hardened sufficiently, to prevent surface damage.



Membrane-Forming Compounds

Liquid membrane-forming compounds consisting of water, resins, chlorinated rubber, and solvents volatility can be used to retard evaporation.

Membrane-forming compounds consist of two types: - Clear or translucent - White pigmented

Application of Membrane-Forming Compounds

Power-driven spray equipment is recommended for uniform application of curing compounds on large paving projects. ( Spray nozzles should be arranged to prevent windblown loss of curing compounds.)

Concrete surface normally should be damp when coating is applied.

On dry, windy days or during periods when adverse weather conditions could result in plastic shrinkage cracking, applying curing compounds will help prevent the formation of these cracks.

Normally, one smooth even coat is applied at a rate of 150 to 200 square feet per gallon. (Two coats may be necessary to ensure complete coverage and should be applied at right angles to the first coat.)

Curing compounds should conform to ASTM C309.

TOPIC O: Concrete Pavement Depth Probing O-1

TOPIC O: Concrete Pavement Depth Probing O-2 Introduction

The following topic is excerpted from the Construction and Materials Manual (CMM)

TOPIC O: Concrete Pavement Depth Probing O-2

FIELD DETERMINATION OF CONCRETE PAVEMENT THICKNESS BY PROBING

Scope

This method covers the procedure for determining the thickness of freshly placed concrete using a probing device.

Apparatus

1. The probing device shall consist of the following components:

- The probing rod shall be a non-flexing rod with a minimum diameter of 3/8 inch (10 mm) and of such length as to completely penetrate the pavement to be measured.

- The top plate shall be circular or square with a minimum area of 16 square inches. The top plate shall be at least 1/16 inch thick and sufficiently ridged to maintain a surface planeness of at least 1/8 in across the widest dimension intended to be in contact with the concrete pavement surface. A hole shall be centrally located and of diameter as to allow for easy maneuvering along the length of the probing rod. It shall be fitted with a locking device so when locked to the probing rod, the angle between the top plate and the probing rod will be 90 degrees.

2. The base plate shall be circular or square in with a minimum area of 80 square inches and of such rigidity, when in place, to allow for the probing rod to be pushed against it without flexing.

3. The anchoring spike shall be of diameter and length to securely anchor the base plate.

4. A bridge that will span the full width of the freshly laid concrete, that will support a person, and of such height as to allow for the use of the probing device.

5. A tape, ruler or other measuring device of such length as to measure the depth of penetration of the probing device into the plastic concrete pavement.

Procedure

1. Select a random longitudinal location within the unit to be measured. Select two transverse locations between the longitudinal joint and the pavement edge at the longitudinal location selected.

2. Place the base plates at the selected locations and secure with the anchoring spike. Make sure the locations of the base plates are well referenced so they may be found once the paver has passed.

3. Position the bridge at the selected longitudinal location and locate one point.

4. Assemble the probing device. Keeping the probing rod as perpendicular as possible to the pavement surface, insert the rod into the plastic concrete, until the rod strikes the base plate.

5. Slide the top plate down the probing rod until it makes contact with the pavement surface and lock to the probing rod.

6. Withdraw the probing device. Measure the length of the probing rod inserted into the plastic concrete from the underside of the top plate to the end of the probing rod. Record this measurement to the nearest 1/8 inch (even millimeter).

7. Locate the second point and repeat steps 4, 5, and 6.

Report

1. Average the measurements from step 6 and 7 above. When a single measurement exceeds the plan thickness by 1/4 inch, use the plan thickness plus 1/4 inch in determining the unit’s average thickness. Record the average to the nearest 1/16 inch.

2. Report the average as the thickness of the unit being measured.

November 2010 Page 12 CMM 8.70 Materials Testing and Acceptance - Concrete

TOPIC P: Trial Batching P-1


Introduction Does the procedure for laboratory batching accurately simulate truck-mixing? How are mix proportions adjusted based on trial batch test results? What data is required on the final Mix Design Report?

Topic Summary After the calculations are done it’s time to find out if the mix proportions perform as designed. ASTM C 192 Laboratory Trial Batching of Concrete Mixtures outlines procedures that are not intended to simulate the affect of truck batching on the mixture you have designed. The ASTM procedure is considered to be the “ideal” condition for specimen preparation, and will produce more consistent results than truck-batching due to the high degree of control involved. For example, laboratory batching requires weighing batch proportions to within 0.3% of the calculated weight. Batching in a ready-mix plant is only required to be accurate to within 3% for each ingredient weighed. Better control of temperature and moisture contents of aggregates during lab batching also results in a more accurate representation of the fresh properties of the mixture.

One physical property better predicted by truck-batching than lab-batching is air content. Air voids in the mix originate from air initially trapped in the dry aggregates, air dissolved in the mix water, and air introduced as a result of the tearing, kneading, and folding action of mixing. The mixing action in a small laboratory mixer cannot accurately simulate that of a truck or central-mix drum so air entrainment dosage rates will probably have to be adjusted during production. This difference is usually not an issue because there are so many factors that cause variations

in air content that it will be monitored closely and adjusted anyway.

Whether or not the ASTM procedure really predicts your truck batching accurately enough is up to you. Tweaking these procedures to make them more representative of your concrete production process is not an uncommon practice. If you wish, experiment with simultaneous side-by-side laboratory and truck-mix trial batching to see which process is most effective for you.


Equipment List Concrete Mixer – 5 cu ft minimum drum capacity (driven by electric motor preferred) Stop watch or Timer Digital Scale – 100 lb minimum capacity (reads to 0.05 lb accuracy or within 0.1% of the

sample to be weighed) Equipment to determine moisture content of each type of aggregate Separate containers for weighing each material (eg. – 5-gallon buckets) Graduated Pipette or Medical Syringes – 15 ml for air-entrainment and 60 ml for water

reducing admixture (use magic marker to write the admixture name on each) Bulb Syringe or Restaurant-style Ketchup Bottle Wet burlap Wheelbarrow or large flat pan Flat, level non-absorbent surface Thermometer Slump Test Equipment – slump cone, scoop, tamping rod, and ruler Method of Consolidation: 5/8” Rod or Internal Concrete Vibrator Air Content Test Equipment – air meter, scoop, rubber mallet, and strike-off float or bar Unit Weight Container – (size based on maximum nominal aggregate size), and

plexiglass strike-off plate Cylinder or Beam Molds – three for each specified test age (eg. – 28 days) and caps or

plastic bags Nonabsorbent, flat, level, surface to perform tests of fresh concrete

Materials (per batch) The quantities listed below are not laboratory batch weights. They are recommended quantities to have on hand to provide a sufficient amount of material for weighing and batching one trial batch. It is suggested the absolute minimum amount of material to have on hand be sufficient to produce six trial batches. That is, six times the amounts listed below.

Amount of material for one trial batch: Type I Portland cement – 80 lbs Fine aggregate – 200 lbs (maintain all aggregate moisture contents above SSD) Coarse aggregate –

1. If Nominal Max = Size No. 1 (¾”), then 300 lbs2. If Nominal Max = Size No. 2 (1½”), then 200 lbs Size No. 1 & 150 lbs Size No. 2

Fly ash (Class C) – 25 lbs Air entraining agent – 20 ml Water reducing admixture – 60 ml


Review: For a QMP Concrete Pavement project, if you batch laboratory mixes perfectly what is the minimum number of batches you would make? 1SSHSC 715.2.3.1(1)

Since we aren’t perfect, how many batches should we plan per mix type?

For a QMP Structures project, if you batch laboratory mixes perfectly what is the minimum number of batches you would make? 1SSHSC 715.2.3.2(1)

Since we aren’t perfect, how many batches should we plan per mix type?

How much can one mix type vary before another series of trial batches is required? 1SSHSC 710.4(5)

1"SSHSC" refers to the WisDOT Standard Specifications for Highway and Structure Construction.

Preparation of Materials Temperature – All materials shall be brought to room temperature in the range of 68 to 86°F. Cement & Fly Ash – Shall be stored in a dry place, in moisture-proof containers. If necessary,

remove all lumps using a No. 20 sieve. Aggregates – Take precautions to avoid segregation. Maintain all aggregate sizes in a

saturated condition with excess surface moisture at least 24-hours prior to use. If needed, add water in sufficiently small enough quantities to avoid water loss by draining (ie.-don’t get carried away with adding water). It is not required, but suggested to cover aggregates with plastic sheeting and/or wet burlap.

Admixtures – Supplied in clearly marked containers to prevent misidentification.

LABORATORY BATCHING INSTRUCTIONS

Pre-batching Preparation Step 1. Reduce Mix Design proportions per cubic yard to trial batch size (See Topic H).

The lab batch quantities should produce 10% more volume than needed.

Step 2. Determine the moisture contents (MC) of fine and coarse aggregates by oven-dry or stovetop methods.

a. Adjust aggregate batch weights for variation in moisture content from SSD.

b. Adjust batch water quantity either up or down based on aggregate MCs.

Step 3. Prepare containers by weighing them individually and writing their empty weights (tare) on the side of each container.

a. Cement usually in a 5-gallon bucket that is always kept dry.

b. If used, fly ash usually in a 6-inch cylinder mold that is always kept dry.

c. Fine aggregate usually in a 5-gallon bucket.

d. Coarse aggregate usually in two or three 5-gallon buckets depending onwhether Size No. 2 aggregate is used or not.

e. Mix water usually in two 6-inch cylinder molds.

f. Extra mix water container usually one more 6-inch cylinder mold.


Step 4. Prepare for dosing admixtures. Use a method that doses using milliliters. The conversion factor of 1 fluid ounce = 29.57 ml should be used.

a. Clearly label pipettes or graduated syringes with the name of the admixture tobe used.

i. Use separate receptacles for each.

ii. Do not cross-contaminate air entrainment agents with water-reducingadmixtures because set time and strength may be severely affected.

b. If using syringes, a 20 ml size should be large enough for air-entrainment anda 60 ml size should be large enough for the water-reducing admixture.However, the size needed should be double checked before purchasingthem.

Step 5. Weigh the calculated amount of cement.

Step 6. If used, weigh the calculated amount of fly ash.

Step 7. Weigh the calculated amount of each type of aggregate.

Step 8. Weight the calculated amount of mix water.

a. Divide one-third of it into one container.

b. Divide the other third into another container.

c. Place both molds on the scale at the same time and estimate 1/3 & 2/3 ineach. The split doesn’t have to be exact, but the total water weighed does.

d. Extra mix water container (6-in cylinder mold) shall be filled until the waterand the mold weigh exactly 5.00 pounds. This water will be used in the eventthe calculated mix water does not produce the desired slump.

Step 9. Measure the calculated dosage of each admixture. The time, sequence, and method of adding some admixtures to a batch of concrete can have important effects on concrete properties such as time of set and air content. Check manufacturer’s recommendations for the addition of admixtures to small laboratory batches. Do not change the method of adding admixtures between batches. If batching information is not available, the following is recommended:

a. Add air-entraining agent (AE) to the two-thirds portion of mix water.

b. Add water-reducing admixture (WR) to the fine aggregate.

c. Do not allow AE and WR chemicals to come in contact with each other priorto their addition to the mixer.

Step 10. Prepare to “Butter” the mixer prior to the first batch by mixing a very small batch of mortar proportioned to simulate the test batch.

a. Start by weighing 5 lbs of cement in a cylinder mold (5 lbs + mold).

b. Weigh fly ash, if used, in a cylinder mold. Calculate weight by multiplying 5times fly ash batch weight (cu yd) divided by cement batch weight (cu yd).


c. Weigh fine aggregate in a cylinder mold. Calculate weight by multiplying 5times fine aggregate batch weight (cu yd) divided by cement batch weight (cuyd).

Laboratory Batching Now you are ready to start adding trial batch materials to the mixer. Have your stop watch or timer ready to start when the cement is added. Have damp burlap ready to cover the mixer when it’s idle. NOTE: Hand mixing is not allowed for trial batching concrete mixes used on WisDOT projects.

Step 11. “Butter” the mixer.

a. Add the above Butter ingredients to the mixer with just enough mix water tomake a thick slurry that flows well enough to coat the interior of the mixer.

b. Discharge the excess butter material from the mixer and discard it.

c. Cover the open end or top of the mixer with damp burlap to slow drying of theinterior of the mixer.

Step 12. Before starting the mixer, remove the burlap and add the coarse aggregate with the 2/3rd portion of mix water.

Step 13. Start the mixer, then add the fine aggregate and cement with the mixer running.

Step 14. Start the stop watch or timer to track the elapsed mix time.

a. Run the mixer for 3 minutes.

b. Then stop the mixer andleave it as rest for 3minutes.

c. Run the mixer again for a 2minute final mixing.

Step 15. During the initial 3-minute mix period, using the remaining 1/3rd mix water, carefully but quickly add the correct amount of water to bring the slump to the designated consistency before 3 minutes has expired.

a. Try squirting a stream of water into the mixture using either a bulb syringe orKetchup bottle. Do not add water too quickly because the water-reducingadmixture may kick-in suddenly causing a rapid increase in slump that mightexceed specifications.

b. If the calculated mix water does not produce the desired slump, use the extramix water in the 6-in cylinder mold weighing exactly 5.00 pounds. If used,remember to weigh the remaining amount after batching, testing, and castingspecimens. This allows you to calculate the water demand and yield of themix.


Step 16. After the final 2-minute mix period has expired, discharge the mixture into a wheelbarrow or into a pan and perform temperature, slump, unit weight (density), and air content tests as taught in the PCCTEC I program. In addition, cast the required number and type of test specimens.

What to Expect The slump must be within 0.5” of the specified slump. The air content must be within 1.0% of the specified range. Almost everyone misses these two requirements on the first batch. Until water demand and air content dosage rates are known more accurately, it’s hard to predict what will happen in the first batch.

Batch Adjustments Although slump is important, the two most critical properties to key in on are air content and yield (density).

SLUMP – add or reduce batch water.

AIR CONTENT – adding or reducing air entraining changes the density.

YIELD – Total batch weight divided by wet density of mix.

Mix Design Report SSHSS Section 715.2.1 – Ensure that the concrete mix report includes a cover sheet with signature blocks for both the mix developer and the engineer. Have the mix developer sign and date each copy attesting that all information in the report is accurate. The engineer will sign and date each copy of the report. The engineer’s signature verifies that the engineer had the opportunity to review the mix report, to check that it meets the concrete mix requirements, and to comment. The engineer will return a signed copy to the contractor within 3 business days of receiving the report.

TOPIC Q: Data Entry

TOPIC Q: Data Entry Q-1

MATERIAL DATA REPORTING FOR QC, QA, QV, IA ON HIGHWAY CONSTRUCTION PROJECTS

The above is from the Atwood Systems website:

http://www.atwoodsystems.com/resources/

http://www.atwoodsystems.com/resources/

May 2015 Page 1

Construction and Materials Manual Wisconsin Department of Transportation

Chapter 8 Materials Testing, Sampling, Acceptance Section 10 Materials - General

Materials sampling and testing methods and documentation procedures prescribed in chapter 8 of the CMM are mobilized into the contract by standard spec 106.3.4.1 and standard spec 106.3.4.3.1.

8-10.1 Control of Materials

8-10.1.1 Approval of Materials Used in Work

The service life of a highway is dependent upon the quality of the materials used in its construction, as well as the method of construction. Control of materials is discussed in standard spec 106.1. The spec provides that only materials conforming to the requirements of the contract must be used, and the contractor is responsible for furnishing materials meeting specified requirements. Only with permission of the engineer can the contractor provide materials that have not been approved, as long as the contractor can provide evidence that the material will be approved later. The department's intention is to hold payment of items until the required materials information is provided by the contractor.

The standard specs encourage recovered and recycled materials to be incorporated into the work to the maximum extent possible, consistent with standard engineering practice. Standard spec 106.2.2 and Wisconsin statute 16.754 require the use of American made materials to the extent possible. On federally funded projects, all steel products must be produced in the United States, and manufacturing and coating processes must be performed in the U.S. These "Buy America" requirements are discussed in CMM 2-28.

(12) Material Coordinators

Section 8-10-1.2 revised to correct material coordinator designations.

8-10.1.2 Contractor and Department Designated Materials Persons

Standard spec 106.1.2 requires the contractor to designate a Contractor's Project Materials Coordinator (CPMC) who will be responsible for submitting all contractor materials information to the engineer. The department should also designate a WisDOT Project Materials Coordinator (WPMC) who will be in direct contact with the contractor's designee.

Standard spec 106.1.2 requires the CPMC to communicate with all subcontractors to ensure that sampling, testing, and associated documentation conforms to the contract. The contract also makes the CPMC responsible for submitting materials information from the prime contractor and subcontractors to the WPMC, promptly reporting out-of-specification test results, collecting and maintaining all required materials certifications, and regularly communicating with the WPMC regarding materials issues on the contract.

The WPMC should provide a project-specific sampling and testing guide (EGuide) to the contractor at the preconstruction conference. The EGuide is created by clicking on the "Systems Links" tab and following "Site Log-In" sub-tab for EGuide (a username and password are required):

http://www.atwoodsystems.com/Eguide.htm

Both the CPMC and WPMC should review and supplement the E-guide before work operations begin to ensure that testing methods, frequencies, and documentation requirements conform to the contract.

The CPMC and WPMC are charged with working together throughout the life of the contract to ensure that contract materials requirements are met and any issues that might arise related to either non-conformance or non-performance are dealt with promptly. The ultimate goal is to make sure that problems with materials are brought to light and timely corrective action taken before those materials problems compromise the quality or acceptability of the completed work.

The CPMC should coordinate contractor materials related activities and do the following:

- Establish methods and work expectations with the WPMC.

- Provide all QMP test data and control charts from the prime contractor and subcontractors.

- Deal with all materials-related concerns from the WPMC.

The WPMC is responsible for administration of the contract with regards to contract materials requirements and should do the following:

- Communicate or meet weekly with the CPMC to discuss outstanding materials issues on the contract.

- Monitor the submittals from the CPMC to ensure timeliness and completeness.








http://www.atwoodsystems.com/Eguide.htm

CMM 8-10 Materials - General

May 2015 Page 2

- Review contractor submittals to verify materials requirements are met.

- Inform the Project Leader of non-conforming materials issues and discuss actions to be taken.

- Prepare materials documentation for inclusion into the project files.

Materials coordinators' training is available and recommended for all contractor and department personnel who work with materials on WisDOT projects. The training provides details about the department's materials acceptance process as well as the roles and responsibilities of project materials coordinators. Materials coordinators' training can be accessed at:

http://www.uwplatt.edu/htcp/MCT.

8-10.2 Approval of Materials

All materials used in a project are subject to the engineer's approval before incorporation into the work. Approval of materials is discussed in standard spec 106.3. Approval is generally accomplished by material tests and/or analysis. This can be done by using approved product lists, certification, or sampling and testing. Unless the contract specifies otherwise, the contractor must follow manufacturer's recommended procedures for products incorporated into the work. Refer to CMM 8-45 for details of acceptance types.

8-10.3 Quality Management Program

Sampling and testing on WisDOT projects is performed according to the Quality Management Program (QMP). QMP is presented in CMM 8-30 and the following CMM sections.

8-10.4 Independent Assurance Program

The Independent Assurance Program (IAP) is an element of the Quality Management Program intended to ensure that test data from project acceptance testing is reliable, including sampling procedures, testing procedures, and testing equipment. Quality verification (QV), quality assurance, (QA), and quality control (QC) are integral parts of the IAP. Further information about the Independent Assurance Program can be found in CMM 8-20.

8-10.4.1 Quality Verification (QV)

Quality verification (QV) sampling is done by a department representative, and is taken independently from the quality control samples to validate the quality of the material.

8-10.4.2 Quality Assurance (QA)

Under the quality assurance (QA) program, a department representative observes sampling and testing performed by the contractor, by testing split samples. Further detail about quality verification and quality assurance is provided in CMM 8-20.

8-10.4.3 Quality Control (QC)

Quality control for materials testing includes all contractor/vendor operational techniques and activities that are performed or conducted to fulfill the contract requirements.

8-10.5 Nonconforming Materials

8-10.5.1 General

The department does not want material not meeting contract specifications incorporated into the work. Standard spec 106.5 gives the engineer the authority to either reject nonconforming materials or to allow the nonconforming materials to remain in place. If materials are found to be unacceptable before or after placement into the work, the engineer may reject the materials, and the contractor must remove the materials from the site at no cost to the department. Materials that have been tested and approved at their source or otherwise previously approved, but have become damaged or contaminated before use in the work, are also subject to rejection by the engineer.

To ensure consistency in the decisions made for acceptance of non-conforming material or workmanship, the engineer should involve the region oversight engineer before finalizing any decision. This will help keep central office informed about contractor or material problems that may require action with a change in specifications or discipline of a contractor. If any technical questions remain about the acceptance or rejection of nonconforming materials refer to the appropriate technical expert in the Bureau of Technical Services.

8-10.5.2 Nonconforming Materials Allowed to Remain in Place

8-10.5.2.1 Deciding Whether or not to Allow Material to Stay in Place

Good engineering judgment is required when making decisions on nonconforming materials. The engineer may choose to approve nonconforming materials, allow them to remain in place, and adjust the contract price. When making the decision to direct the contractor to remove and replace the materials versus leave the materials in place, it's important to consider the following:







http://www.uwplatt.edu/htcp/MCT.



CMM 8-10 Materials - General

May 2015 Page 3

- Long-term consequences on quality and durability.

- Implications on the project's life cycle costs, service life, serviceability, and maintenance.

- Socioeconomic, environmental, and aesthetic considerations.

- Impacts on traffic, staging, and construction timeframes.

8-10.5.2.2 Deciding Whether or Not to Apply Price Reduction

After the engineer has decided to allow nonconforming materials to remain in place, he or she must carefully evaluate each situation in deciding whether to take a price reduction. The goal is to achieve consistency statewide in administering price reductions for nonconforming materials that are allowed to remain in place. Results of retests and related quality tests should be considered. The following list includes some examples of the types of factors the engineer must consider to decide if a price reduction is warranted and how much it should be:

- Has the contractor been conscientious to provide quality by carefully controlling materials and construction operations?

- Has the contractor been proactive and made good use of QC data to maintain and improve quality?

- Did the engineer provide the contractor with non-conforming test results within the contractual timeframe, if specified?

- If timeframes are not specified, did the engineer provide non-conforming test results in time for the contractor to make process or materials corrections?

- Upon becoming aware of a materials quality problem, has the contractor responded quickly to correct it?

- Is the nonconforming test an isolated incident or a recurring situation?

- How does the nonconforming test compare to the rest of the project data:

- Have material test results been well within specification requirements or consistently at the very limit of what is acceptable?

- How many tests are nonconforming vs. how many tests have passed?

- How far out of spec is the non-conforming test?

8-10.5.3 Price Reductions Specified in the Contract with Administrative Items

If price reductions are included in the specifications or special provisions for certain nonconforming items, the price reductions should be administered using the appropriate 800 series administrative items. Since the price reductions are included in the contract language, the engineer can add the 800 series items to the contract without going through the complete change order process. Approval by a DOT representative and contractor representative are not necessary, though it's good practice to communicate the changes to all parties. Further guidance on the 800 series administrative items is provided in CMM 2-38.

For payment of nonconforming items with associated administrative items, pay for the installed quantity and bid price of the work item under the original bid item. The pay reduction will be accounted for using the administrative item. Compute the price reduction by multiplying the quantity of nonconforming material by the original unit price and the percent price reduction. The pay units of all administrative items are DOL. Document all calculations, and pay for the (negative) total calculated price reduction as the pay quantity, with 1 dollar as the pay unit.

Example 1

- Contractor placed total of 19,000 SY of Concrete Pavement 9 inch - 670 SY (12' x 500') is 1/8" - 1/2" under plan thickness - Standard spec 415.5.2 directs to pay 80% contract price for this range (20% reduction) - Bid unit cost is $35/SY Using original bid item, pay 19,000 SY at $35/SY = $655,000 Compute price reduction = 670 SY x $35 x -0.20 = -$4,690 Add the administrative item 804.6005 Nonconforming Thickness Pavement to the contract, with

unit price of $1.00 Pay quantity of -$4,690 Net pay = $655,000 - $4,690 = $650,310

Paying for nonconforming items this way allows for clean tracking of as-built quantities. The use of



July 2014 Page 1

Construction and Materials Manual Wisconsin Department of Transportation Chapter 8 Materials Testing, Sampling, Acceptance Section 45 Materials Testing and Acceptance - General

Materials sampling and testing methods and documentation procedures prescribed in chapter 8 of the CMM are mobilized into the contract by standard spec 106.3.4.1 and standard spec 106.3.4.3.1.

8-45.1 Acceptance Procedures, Documentation, and Reporting

Documentation and reporting for materials acceptance is equal in importance to Item Record Account documentation. The basis of acceptance for contract materials is accomplished in several ways, depending on the material. The type of reporting and documentation is a function of the acceptance type.

Materials test reporting and documentation is to be done using the WisDOT electronic Materials Tracking System (MTS). The MTS is a computerized filing and reporting system for construction materials tests and documents. All construction materials tested and inspected for WisDOT projects are reported on the MTS. The overall MTS has three basic components, the MTS (LAN/WAN attached), Materials Information Tracking System (MIT), and the Materials Tracking website. Region and central office laboratory personnel can enter data directly into the Oracle database via a Local Area Network (LAN) attachment provided through the MTS. The MIT is used for entering tests from the field.

The engineer should follow these guidelines for material documentation:

- Inspect all manufactured products as soon as possible after delivery.

- Include all approved lists, certified sources, and pre-qualified products.

- Record in the project record relevant inspection information.

- Verify that products delivered match the certifications, approved list, etc.

- Review all Certifications of Compliance and Certified Reports of Test and Analysis.

- Reference all Certifications, shop inspection reports, and other external documents using the MTS/MIT prefix 900 report.

All materials documentation and reporting must be completed and entered in the MTS no more than 60 working days after the work completion date.

Manufactured products must be inspected at the job site as soon as possible after arrival for evidence of damage or noncompliance even though these materials are covered by prior inspection testing or certification.

Those materials normally source inspected, but which arrive at the job without appropriate marking, indicating that they have been accepted at the source, must be field inspected or tested and the basis for acceptance must be documented in the inspector’s diary.

8-45.1.1 Materials Testing and Acceptance Guide

The Materials Testing and Acceptance Guide, CMM 8-50 details many of the sampling, testing, and documentation requirements for various materials. The instructions shown in this guide are recommended minimum requirements. In many cases, it may be appropriate to increase the frequency and scope of certain testing and acceptance activities in order to properly administer the materials specifications. In all cases, it is appropriate to closely observe produced materials for visual evidence of changes in quality and to then adjust testing frequencies, as required, to adequately evaluate their quality.

Sampling and testing procedures of certain unique materials are described in the standard specs and other contract documents. The instructions in this guide are intended to supplement those in other contract documents.

8-45.1.2 E-Guide

E-Guide is an automated system that produces condensed sampling, testing and documentation guidance for material requirements for a project. It generates the guidance in two basic ways. For the project bid items, the system automatically generates guidance. For non-standard special provision (SPV) items, the system requires manual input of the SPV material requirements contained in the project proposal. CMM 8-50 should be cross checked when an E-Guide is developed since it contains detailed information and it breaks material information out by type. The E-Guide system for developing a project specific sampling and testing guide is available at:

http://www.atwoodsystems.com/syslinks.cfm

The WisDOT project material coordinator shall prepare the E-Guide and provide a copy to the contractor's material coordinator. Consult the region materials engineer or region person responsible for construction





CMM 8-45 Materials Testing and Acceptance - General

July 2014 Page 2

materials for guidance when developing the E-Guide.

The E-Guide does not supersede material requirements in the Standard Spec or the CMM. The contractor is contractually bound to supply the information if required in the Standard Spec, CMM or Special Provisions.

The region materials engineer or region person responsible for this area must be consulted regarding doubts as to the adequacy of compliance of source inspected materials, need for field inspection and reports, waiver of testing, unlisted items, evaluation of certifications, or other questions regarding acceptance procedures.

Table 1 below defines the general documentation requirements for each materials acceptance type. Table 2 provides the MTS prefixes for all material types. Figure 1, Figure 2, and Figure 3 show example test reports.

CMM 8-45 Materials Testing and Acceptance - General

July 2014 Page 3

Table 1 Documentation Requirements for Different Acceptance Types

Documentation Required

Acceptance Type

MIT/MTS Document

MTS Documentation

Time Line Remarks

MTS Report. Verification tests- C.O. Laboratory

Various MTS prefixes as appropriate. See Table 2 for a list of prefixes.

No later than one week after completion of test.

Test entry by C.O. Lab personnel.

Materials Diary entry

MTS reference report.

Approved Product Lists- WisDOT

Reference on MTS prefix 900 or 155

No later than 60 days after contract work completion date.

Test entry by project personnel.

Form DT 1823, Report of Shop Inspection.


Materials Diary entry.

Source or Shop Inspection



Test entry by project personnel.

Source sampled materials tested and reported by C.O. personnel (see verification tests C.O. Lab above).

Cert. of Compliance


Materials Diary entry.

Manufacturers Certification of Compliance



See note below [1].

Cert. Report of Test


Materials Diary entry

Certified Report of Test



See note below [1].

Verification tests-MTS Report.

Field Sampling and Testing

Aggregates- MTS prefix 162, 217

HMA- MTS prefix 254

HMA Nuclear Density- MTS prefix 262

Concrete Cylinders – MTS prefix 130

Earth Work Density- MTS prefix 232

No later than one week after completion of test.

All aggregate and HMA QV testing done must be entered by the qualified lab doing the testing.

When QV and Companion Cylinder testing is done the data must be entered by the qualified laboratory doing the testing.

Quality Management Program (QMP) Quality Control (QC) tests.

MTS Report.

MRS Report (Structures Masonry Data)- contractor entry.

MRS Report (IRI ride data) contractor entry.

Field Sampling and Testing

MTS Report 155 No later than 60 days after contract work completion date- prefix 155 data.

MRS data is to be input by the contractor as it is developed.

Refer to Figure 1, Figure 2, and Figure 3 for examples of prefix 155 reports for verification of contractor QMP and QC testing.

[1] Certifications must be evaluated promptly for adequacy, completeness, and compliance with the specifications. The certification reviewer must make appropriate notations, initial, and date the document when the review is completed.

TOPIC R: Appendix R-1

Mix Design, Research and Software

QMP Award

Correction Page

Course Evaluation

TOPIC R: Appendix R-2

INTRODUCTION: Mix Design, Research and Software

While not an endorsement for any product, be aware that mix design research and software is being conducted and developed. Information on two products, HIPERPAV and COMPASS follow.

The objectives of this mix design, research and software is to seek ways to optimize materials selection and construction methods to improve the longevity of Portland Cement Concrete pavements. Iowa led pooled fund study Project #: TPF-5(066)

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.

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.

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 :

Corrections

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]

Course Evaluation

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:

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Unacceptable

Effectiveness of course presentation:

5

4

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Responsiveness and interaction with students:

5

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1

Ability to communicate: 5 4 3 2 1 Knowledge of course content: 5 4 3 2 1

3. Please fill in and rate overall effectiveness of laboratory instructor(s)/guest lecturer(s):



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5

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Comments: Please make additional comments about individual laboratory instructor(s)/guests lecturer(s) quality of instruction:

4. Administrative Evaluation:



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Registration procedure:

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Parking

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Comments: Please make additional comments about registration procedures, classroom atmosphere, laboratory equipment, and parking:

5. What did you like most about the course? 6. What did you like least about the course? 7. Please comment about overall course quality and length: 8. The HTCP may wish to use your comments in our next brochure To use your comments, we must have your name and address: Name: Title: Organization: Address: City/State/Zip: Phone:

Portland Cement Concrete Technician II

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