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| FHWA > Engineering > Pavements > Concrete > Evaluation of Procedures for Quality Assurance Specifications > Appendix D |
APPENDIX D: SUMMARY OF AGENCY PCC SPECIFICATIONS RECEIVEDKansasQuality ControlThe contractor is responsible for providing a QC plan that must be approved by the engineer prior to construction and providing qualified personnel and equipment to conduct QC testing. The contractor must allow the engineer access to the laboratory to observe any and all testing procedures, calculations, test documentation, and plotting of results. At a minimum, values for percent air, slump, unit weight, and gradation must be plotted on control charts. QC tests include aggregate gradation, slump, air content, unit weight/yield, compressive strength, flexural strength, material passing #200, percent moisture in aggregate, temperature, and density of fresh concrete. Cores are to be tested once per each sublot, where a sublot is the day's lot production divided into five sublots of equal surface area. Quality AssuranceQA is the responsibility of the engineer and is accomplished through verification testing by Kansas DOT. The engineer conducts verification testing on aggregate gradation, slump, air content, unit weight/yield, compressive strength, flexural strength, material passing #200, percent moisture in aggregate, temperature, and density of fresh concrete. AcceptanceAcceptance or rejection of material is based on the contractor's QC tests as verified by the engineer's tests. Should the results of the two tests disagree, the engineer's results will be used to determine acceptance or rejection. If the test results are disputed, referee testing will be conducted on additional samples by an independent laboratory. The referee test results will then be used for acceptance. Pay FactorsPay factors are assigned for smoothness, compressive strength, and thickness. The smoothness pay factor is based on the California profilograph. Values for this pay factor were not provided. Pay factors for thickness and compressive strength are based on a quality index for each characteristic. The quality index (Qi) is calculated as follows: (64)Qi = ( Xavg - LSL ) / S where: Xavg = average measured thickness or compressive strength of all cores in the lot The quality index is then used to calculate a pay adjustment factor according to the following table: Concrete Thickness and Compressive Strength Pay Adjustment
*Calculated as P = 60 + (Q × 32) A composite pay factor for the lot is then calculated as Pc = (Pt × Ps)/100. QC/QA Tests for Kansas
NA = Not applicable IllinoisQuality ControlThe contractor is responsible for providing a QC plan that must be approved by the engineer prior to construction and providing qualified personnel and equipment to conduct QC testing. The contractor must allow the engineer access to the laboratory to observe any and all testing procedures, calculations, test documentation, and plotting of results. At a minimum, the contractor must have a level 1 PCC technician at the job site, as well as a level 2 PCC technician at the plant during mixture production and placement. QC tests include aggregate gradation, slump, air content, unit weight/yield, temperature, and compressive or flexural strength. Quality AssuranceThe engineer is responsible for all QA testing on split samples. The split sample is one of two equal portions of a field sample. At the engineer's discretion, he/she may also obtain independent field samples for testing. The results of the QA tests will be made available to the contractor as soon as they are completed. In the event that the contractor's or the engineer's tests for air content and strength are not within specification limits, referee testing will be conducted by Illinois DOT or by a mutually agreed upon laboratory at the contractor's option. AcceptanceAcceptance of the material is based on: contractor's compliance with all contract documents for QC, validation of the contractor's QC test results by comparison with the engineer's QA tests, comparison of the engineer's QA test results with the specification limits using samples independently obtained by the engineer, and referee test results for unresolved failing tests obtained by the contractor or the engineer. Pay FactorsPay factors are assigned for smoothness and thickness. QC/QA Tests for Illinois
NA = Not applicable IowaQuality ControlThe contractor is responsible for providing a QC plan that must be approved by the engineer prior to construction and providing qualified personnel and equipment to conduct QC testing. The contractor must allow the engineer access to the laboratory to observe any and all testing procedures, calculations, test documentation, and plotting of results. At a minimum, the contractor must perform QC tests on the unit weight of plastic concrete, aggregate gradation, flexural strength, air content, slump, and water-to-cement ratio. Quality AssuranceThe engineer is responsible for QA and acceptance of the material. QA is accomplished by conducting verification sampling and testing, observing the QC sampling and testing, taking additional samples for testing at any time, and monitoring control charts. Results of the verification tests will be made available to the contractor as soon as they are completed. Verification testing frequency will be at the discretion of the engineer, but must not be less than 10 percent of the QC tests. Verification testing will be conducted on those properties tested for QC. AcceptanceAcceptance of the material will be based on the contractor's QC test results as long as the results agree with Iowa DOT's test results. Acceptance for thickness will be based on samples tested by the engineer. Coring for thickness will be on a lot-by-lot basis, where 1 day's production is considered a lot, which is divided into three equal sublots for testing. Pay FactorsPay factors are assigned for smoothness, thickness, and flexural strength. The pay factor for smoothness was not provided. The pay factor for thickness is determined using the following table:
* The thickness index is determined as follows: TI = (Xavg - S) - T, where Xavg = mean core length for the section, The pay factor for flexural strength is determined by subtracting 1 standard deviation from the mean strength according to the following table. The average strength is based on three beams.
1 lbf/inch2 = 6.89 kPa The composite pay factor was not provided; however, it appears to be the individual pay factors multiplied together times the contract price. QC/QA Tests for Iowa
NA = Not applicable New JerseyQuality ControlAll plants producing concrete for New Jersey DOT projects shall have a QC plan in place, as outlined in "Requirements for a Portland Cement Concrete Quality Control Plan," June 25, 1998. A QC technician who is certified by the American Concrete Institute as grade I must be available during the production of concrete for any New Jersey DOT project. QC tests for slump, air content, compressive strength, aggregate gradation, and temperature are conducted at the plant. Concrete provided by any producer who has met applicable design, control, and acceptance testing requirements will be presumed to be in compliance with New Jersey DOT's standards at the time of delivery. However, the presumption will not waive the engineer's right to impose pay adjustments. AcceptanceAcceptance of the material is determined through acceptance testing by New Jersey DOT. Acceptance will be based on the results of the slump, strength, and air content tests. Acceptance for compressive strength, slump, and air content will be on a lot-by-lot basis, with a lot being equal to 1 day's production. Acceptance tests will be conducted at a frequency of five per lot. Pay FactorsPay factors are assigned for air content and compressive strength. The pay factor for compressive strength and air content will be determined by the percent defective within the lot. Percent pay adjustments (PPA) are calculated using the following two equations: (65)For PD < 50 : PPA = 3.0 - 0.3PD (66)For PD ≥ 50 : PPA = 26.0 - 0.76PD North CarolinaQuality ControlThe contractor is responsible for providing a QC plan that must be approved by the engineer prior to construction. During the preconstruction meeting, the contractor and the engineer will determine the types and frequencies of testing that are required to produce materials that meet the specifications. The contractor must also provide qualified personnel and equipment to conduct QC testing. The contractor must allow the engineer access to the laboratory to observe any and all testing procedures, calculations, test documentation, and plotting of results. At a minimum, the contractor must have a technician who is certified to develop the concrete design, control the gradation and quality of the aggregates, and perform the required tests. QC testing must be conducted for aggregate gradation, air content, slump, compressive strength, profile index, and thickness. AcceptanceAcceptance of the material is determined through acceptance testing by North Carolina DOT. Acceptance will be based on the results of the slump, flexural strength, thickness, profile index, and air content tests. Acceptance for slump and air content will be determined at the point of placement at a frequency determined by the engineer. A sample will be obtained immediately after the concrete has been discharged onto the road. Acceptance for thickness and flexural strength will be determined on a lot-by-lot basis, where a lot is 5333.3 yd3 and subsequently divided into four equal sublots. For each sublot, a set of two beams shall be used to test flexural strength. Additionally, two cores shall be taken from each lot to test for thickness. Acceptance testing of the longitudinal profile of the finished pavement must be performed by the contractor in the presence of the engineer. Pay FactorsPay factors are assigned for profile index, thickness, and flexural strength. The pay factor for the profile index was not provided. The pay factor for thickness is determined from the following table:
1 inch = 25.4 mm The pay factor for flexural strength is determined from the following table:
Note: R is the difference between the high and low tests in the lot. If multiple deficiencies occur, the payment is determined by successively multiplying the contract price by the appropriate factor indicated for each deficiency. QC/QA Tests for North Carolina
NA = Not applicable OregonQuality ControlThe contractor is responsible for providing a QC plan that must be approved by the engineer prior to construction and providing qualified personnel and equipment to conduct QC testing. The contractor must allow the engineer access to the laboratory to observe any and all testing procedures, calculations, test documentation, and plotting of results. At a minimum, the contractor must have a concrete control technician (CCT) at the plant or job site and a QC technician (QCT) at the job site. QC tests include aggregate gradation, slump, air content, water-to-cement ratio, unit weight/yield, temperature, and compressive strength. QC tests will be conducted on a lot-by-lot basis, where a lot is the total amount of concrete produced for each mix design. This lot will then be divided and tested by the sublot, where a sublot is equal to 75 m3 of material. Quality AssuranceThe engineer is responsible for all QA. Assurance is accomplished through verification testing, observation of contractor sampling and testing, and additional sampling and testing conducted by the engineer. The results of the verification tests will be made available to the contractor as soon as they are completed. In the event that the contractor's or the engineer's tests are not within specification limits, they shall immediately work together to resolve the difference to avoid having the material rejected as not meeting specifications. Verification testing will be conducted on a lot-by-lot basis, where a lot is the total amount of concrete produced for each mix design. AcceptanceAcceptance of the material is based on verification of the QC tests by Oregon DOT's tests. For aggregate acceptance, verification of the contractor's test values through check tests completed by the engineer will be used. For plastic concrete, acceptance is based on the QC tests performed by the contractor and on tests conducted by the engineer. The engineer may observe the QC tests performed by the contractor and/or conduct tests on all plastic concrete. Hardened concrete will be accepted based on the statistical analysis of the 28-day strength tests of cylinders cast by the engineer. Pay FactorsPay factors are assigned for smoothness, thickness, and compressive strength. The pay factor for smoothness is determined by the following equation: (67)Bonus = 0.00038 ( 80 - PI ) (Quantity) ( Unit Price ) where: PI = average of the two wheel path profiles for the segment The pay factor for thickness is determined using the following table. No additional payment will be made for pavement exceeding the minimum specification.
The pay factor for compressive strength is based on statistical analysis to determine the total percent within the specification limits. This is then used to determine the pay factor for strength. In no case shall payment exceed the contract price. For pay factors less than 1.00, a pay reduction is calculated as follows: (68)Payment = 0.3 ( PF - 1.0 ) ( Contract Bid Price ) A weighted pay factor (WPF) is determined by multiplying PF by a weighting factor fI provided in the contract. The method for determining a composite pay factor (CPF) for these items uses the following formula: (69)
where: WPF = weighted pay factor QC/QA Tests for Oregon
NA = Not applicable PennsylvaniaQuality ControlThe contractor is responsible for providing a QC plan that must be approved by the engineer prior to construction and providing qualified personnel and equipment to conduct QC testing. The contractor must allow the engineer access to the laboratory to observe any and all testing procedures, calculations, test documentation, and plotting of results. At a minimum, the contractor must have a certified technician to develop the concrete design, control the gradation and quality of the aggregates, and perform the required tests. QC testing must be conducted for aggregate gradation, air content, slump, compressive strength, profile index, and thickness. Quality AssuranceQA is accomplished through independent sampling and testing by Pennsylvania DOT for air content, strength, and pavement thickness. Independent assurance testing is conducted to review the QC testing and to check the accuracy of the equipment used for acceptance testing. AcceptanceAcceptance of the material is determined through acceptance testing by Pennsylvania DOT. Acceptance will be based on the results of the slump, strength, thickness, and air content tests. Acceptance for compressive strength and air content will be on a lot-by-lot basis, with testing conducted on sublots of 1400 yd2 (1170 m2). Acceptance for smoothness will be based on the QC profilograph test. Pay FactorsPay factors are assigned for profilograph, thickness, air content, and compressive strength tests. The pay factor for compressive strength and air content will be determined by the PWL for the lot. The pay factor for thickness will be determined by coring. The profile index pay factor is determined using a profilograph and assessing the index in inches per mile per lot. After determining the individual pay factors for each of the above characteristics, the lot payment is calculated using the following equation: (70)Lp = Cp ( [ ( 2Ps + 2Pd + Pa ) / 500 ] + [ Pp - 100 ) / 100 ] ) where: Lp = lot payment QC/QA Tests for Pennsylvania
NA = Not applicable TexasQuality ControlThe contractor is responsible for providing a QC plan that must be approved by the engineer prior to construction and providing qualified personnel and equipment to conduct QC testing. The contractor must allow the engineer access to the laboratory to observe any and all testing procedures, calculations, test documentation, and plotting of results. To complete the required testing, the contractor must provide technicians certified at levels I through IV, depending on the test being conducted. The standard lot size is 6000 yd2 (5000 m2) of surface area of PCC pavement of the same thickness. A sublot is equal to one-fifth of the surface area of a lot. If the final lot is 3000yd2 (2500 m2) or greater, it will be considered a full lot. QC must be exercised on all properties contained in the table entitled QC/QA Tests for Texas. Quality AssuranceQA is accomplished through verification testing conducted by Texas DOT. Independent assurance testing is conducted to review the QC testing and to check the accuracy of the equipment used for verification testing. AcceptanceAcceptance of the material is based on the QC tests and the verification tests. If the contractor's QC test results and the engineer's verification test results are not within tolerances, referee testing will be conducted. If referee tests are requested, the referee test results shall govern. Pay FactorsPay factors are assigned for ride quality, thickness, and flexural strength. The pay factor for flexural strength is based on the following table:
1 lbf/inch2 = 6.89 kPa The pay factor for ride quality was not provided. The pay factor for thickness is determined using the following table:
The pay adjustment factor for each lot is calculated as AF = (SF)(TF). The pay adjustment for each lot is then calculated as: (71)Payment = ( BP ) ( AF ) ( Q ) where: BP = bid price QC/QA Tests for Texas
NA = Not applicable WisconsinQuality ControlThe contractor is responsible for providing a QC plan that must be approved by the engineer prior to construction and providing qualified personnel and equipment to conduct QC testing. The contractor must allow the engineer access to the laboratory to observe any and all testing procedures, calculations, test documentation, and plotting of results. At a minimum, the contractor must have the following certified personnel: aggregate technician 1, PCC technician 1A, PCC technician 2, concrete compressive strength tester, and profilograph operator 1. QC testing must be conducted on the following: aggregate gradation, material passing #200, aggregate moisture, air content, slump, temperature, thickness, profilograph, and compressive strength. Quality AssuranceQA is accomplished through verification testing by Wisconsin DOT for air content, strength, and pavement thickness. Independent assurance testing is conducted to review the QC testing and the verification testing. The independent assurance review will be done in accordance with Wisconsin DOT's Independent Assurance program and may include: split-sample testing, proficiency sample testing, witnessing of sampling and testing, review of control charts, and requesting additional samples for testing. AcceptanceAcceptance of the material is based on the contractor's QC test results. This method of acceptance and payment will continue until it can be shown through verification or the dispute resolution process that the contractor's test results are in error. Acceptance will be based on the results of the strength, thickness, and air content tests. Pay FactorsPay factors are assigned for profilograph, thickness, and compressive strength. The pay factor for compressive strength will be determined by the lot and will be based on the contractor's QC cylinders fabricated for each sublot. A lot is considered to be 1 day's production divided into equal sublots not to exceed 500 yd3 (380 m3). The pay adjustment will be based on the lot's average strength minus 1 standard deviation. The factor is a dollars per yd2 adjustment. The factor is determined from the following table:
1 lbf/inch2 = 6.89 kPa, 1 yd2 = 0.836 m2 The pay factor for the profile index will be determined according to the following table:
1 mi = 1.61 km, 1 inch/mi = 15.8 mm/km The pay factor for thickness will be determined according to the following table:
1 inch = 25.4 mm, 1 ft = 0.305 m These factors are applied according to the units listed in the tables. QC/QA Tests for Wisconsin
NA = Not applicable FHWA-HRT-04-046
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This page last modified on 06/09/06 |
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