Item 403  ASPHALT CONCRETE QUALITY CONTROL AND ACCEPTANCE

403.01  Description

403.02  General

403.03  Quality Control Program (QCP)

403.04  Plant Calibration

403.05  Quality Control Tests

403.06  Verification Acceptance (VA)

403.07  Unconditional Acceptance

403.08  Acceptance Tables for 448 Mixes

 

403.01  Description.  This specification outlines the Contractor requirements for controlling asphalt concrete, asphalt concrete base, or other asphalt mixtures as specified.

403.02  General.  The Department will determine acceptance by Department Verification Acceptance (VA) tests and monitoring reviews as specified.  If the Contractor fails to operate according to its Quality Control Program (QCP), the Department will accept asphalt mixtures by Unconditional Acceptance.

Restoration of VA procedures will be by the Department’s Quality Control Qualification Committee (QCQC) based on District recommendation and review of the Contractor problems, resolutions and QCP.

Acceptance does not relieve the Contractor of responsibility for supplying and installing a finished product conforming to all requirements of the Contract.

403.03  Quality Control Program (QCP).  Create and implement a Quality Control Program (QCP) for each paving season.  This program covers all aspects of input materials testing and handling, mix testing, plant operation, and mix delivery that are necessary to assure that all of the asphalt concrete mix delivered to the paving site meets or exceeds the specification requirements for material properties, coating, and uniformity and is accomplished by accepted practices.  A minimum of 3 weeks before mix production, but no later than February 28, submit the proposed QCP to the Laboratory for review and approval.

Send a copy of the approval letter and approved QCP to the DET in every District in which work is performed.  Keep copies of the approval letter and the approved QCP in each Contractor plant laboratory and plant operation control room.

Failure to comply with the approved QCP may result in removal of personnel in accordance with Supplement 1041, removal from VA, and adversely affect the Contractor’s Prequalification rating.

The QCP is a reflection of a Contractor’s sincerity and ability in producing a quality product.  Development of this program beyond the minimum requirements specified below is encouraged and is taken into consideration by the QCQC when reviewing Contractor plant operation for qualification for VA.

Include in the program:

A.     The assignment of quality control responsibilities.  A Quality Control Manager (QC Manager), holding a Supplement 1041, Level 2 qualification, is required.

B.      Provisions to meet the Department mix specifications.

C.      Procedures for any extra testing (e.g., job start, responses to poor test results or field mix problems, aggregate stock testing, reclaimed asphalt concrete pavement checks, moistures) and any other testing necessary to control materials not already defined in these Specifications.

D.      Copies of worksheets, test reports, and forms used in the quality control.

E.      Procedures for record storage, test equipment maintenance, and documentation.

F.      Method of Quick Calibration and documentation for each plant type.

G.      Procedure for random sampling to be used and documentation method.

H.      Procedure for ensuring that every Contractor employee involved in the testing of asphalt mix and operation of the asphalt plant facility has read the QCP and has on site access to all applicable Department specifications, proposals, policies, and the current approved JMF.

I.       Means to meet the handling and storage requirements of 702.01 and asphalt binder suppliers for all asphalt binders.

J.       Means to meet delivered mixture uniformity/coating and hauling/trucking requirements.

K.      Signature of the QC Manager and, if different, the person in authority to enforce all operations covered by the QCP as outlined in this subsection.

403.04  Plant Calibration.  Conform to the requirements of Item 402.

Before manufacturing asphalt concrete, demonstrate to the Monitoring Team that the Contractor’s facility adequately meets the specification requirements.  Calibrate the plant using procedures approved by the Department.  Perform initial calibrations in the presence of the Monitoring Team.  The Monitoring Team may request a letter of certification and certified data documenting the calibration results, instead of having the Monitoring Team present.

Verify the calibrations biweekly using a Quick Calibration.  However, the Department may request additional Quick Calibrations if there are mix production problems or plant operation concerns.  The Quick Calibration is a quality control procedure developed by the Contractor that verifies the accuracy of a facility to proportion materials to meet the current JMF.  Include the Quick Calibration procedure and data forms in the QCP.  If the difference between current calibration and the Quick Calibration is within ±2 percent, then the current calibration is acceptable.  If the 2 percent variation is exceeded, perform a recalibration of the facility.  Document the Quick Calibration procedure as specified in the QCP and post the procedure and results in plain view in the plant control room and plant laboratory for reference by the Monitoring Team.  Document all data from calibrations in a format approved by the Laboratory, and retain the data for review by the Monitoring Team.

If asphalt concrete is being produced from a batch type facility, verify the accuracy of the aggregate and asphalt binder weighing devices on a biweekly basis.  Include the verification procedure in the QCP.  Document the verification procedure as specified in the QCP and post the procedure and results in plain view in the plant control room and plant laboratory for reference by the Monitoring Team.  Do not allow the deviation between the plant recorded weights and actual weights to exceed 1 percent.  Record all data from verification of weighing devices in a format approved by the Laboratory, and retain the data for review by the Monitoring Team.

403.05  Quality Control Tests.  Perform quality control tests to control the asphalt concrete mix within the appropriate specifications.

Perform all Item 446 and 448 mix testing and quality control according to 441.09.  The Contractor may test a 448 Sublot sample instead of the required quality control test provided the sample is tested in the half day in which the Sublot sample mix was produced and is tested for all required quality control properties.

For mixes that do not use Item 446 or 448 acceptance (e.g. Items 301, 302, and 308, and Supplemental Specification 803), test the mix according to 441.09 for asphalt binder content and gradation (Basic).  Other requirements of 441.09 and 441.10 do not apply.  Control the Basic mixes as follows:

A.     If a single asphalt binder content is more than ±0.5 percent beyond the JMF, immediately take and test an additional sample.

B.      If two consecutive asphalt binder content tests are more than ±0.5 percent beyond the JMF, notify the Monitoring Team and cease production until the problem is corrected.

C.      If the Range difference in any three consecutive asphalt binder content tests is greater than 0.7 percent (for 302 mix) or 0.6 percent (Basic mix, other than 302) immediately notify the Monitoring Team.

D.      If the Range difference in any three consecutive gradation tests for the No. 4 (4.75 mm) sieve is greater than 10.0 percent, immediately notify the Monitoring Team.

E.      If Range deviations as specified continue, cease production.

Range is defined as the difference between the largest and the smallest acceptance test result within an acceptance period (production day or Lot).

403.06  Verification Acceptance (VA).  The Department will perform VA.  If the random Department sampling and testing verifies the accompanying Contractor tests, the results of all the Contractor’s quality control tests for each day (for Basic mix) or the Contractor’s tests for each Lot (for 446 or 448 mix) will determine acceptance.

A.      Sampling.  The Department will perform the VA by testing split (for Basic or 448 mix) or core (for 446 mix) samples.

For plant sampling for Basic acceptance or 441 quality control testing, the Contractor’s technician shall randomly select the truck in which to take a sample by using a random number procedure as outlined in the QCP.  The Contractor’s technician shall give no indication to anyone of the time that the sample is to be taken.  For other than job start, previous mix production problems, low production tonnage, or as requested by the Monitoring Team, exclude the first three trucks from sampling.  Include the random number and sample tonnage location and time of taking on the daily Quality Control Report (Department Form TE-199) with each test.  Tests, other than the required random sample tests, are at the Contractor’s discretion according to the QCP.

Provide a clean area of sufficient size to perform sample splitting.  Split samples by quartering according to AASHTO T 248, Method B and recombining for the Department and Contractor’s sample.  The Department split sample size is generally 22 to 27 pounds (10,000 to 12,000 g).  Except for 446 mixes, ensure that every quality control or Item 448 Sublot sample taken by the technician has a labeled split for the Department.  Wrap and label the Department split samples as to Lot or Sublot, time, location (tonnage), and accompanying Contractor test identification.  Label all cores with a Contractor identifier such that all Contractor cores may be correlated with Monitoring Team VA cores and core data on the Core Reports (Department Form TE-217).  The Monitoring Team will pick up all Department split samples within 4 workdays.  Sample mishandling (careless identification, changing sample size, consistency, or pre-testing) will result in a change to Unconditional Acceptance.

For Item 446 mixes, obtain two acceptance cores at each location according to 446.05.  Take the two cores longitudinally from each other rather than transversely.  Send one set to the District following current procedures.  Test one set of cores at the plant laboratory no later than the following production day.  If necessary in a Monitoring Team review of a comparison problem, the Department may request the Contractor to not destroy cores during testing.  Trim cores by sawing such that tack coat and other pavement courses are removed.

For Item 448 mixes, conform to the procedures of Supplements 1035, 1038, 1039, and 1043 except take samples from a truck at the plant.  If workmanship problems continue on the project (segregation, etc.) or if quality control problems persist, the Monitoring Team may require sampling on the road according to Supplement 1035.  Lots will be 3000 tons (3000 metric tons), and Sublots will be 750 tons (750 metric tons).  However, when production is limited to less than 3000 tons (3000 metric tons), consider the quantity produced as a partial Lot.  Split and test all Sublot acceptance sample locations, as selected by the Monitoring Team and taken by the Contractor.  The Contractor may test a Sublot sample instead of the required random quality control test provided the sample is tested in the half day in which the Sublot sample mix was produced and is tested for all required quality control properties.  Label Department split samples as Sublot or quality control samples.

B.      Reporting.  Report all testing performed and sample identification on a Quality Control Report (Department Form TE-199).  Deliver (fax, e-mail, hand) completed Quality Control Reports and Core Reports (Department Form TE-217) by the end of each day in which testing is conducted, but not more than 1 day after cores are cut.  If desired by the Monitoring Team and always for unsigned E-mail versions, mail the originals.  After startup adjustments, report any plant operation changes on the Quality Control Report.  Ensure that each Quality Control Report contains technician comments as to production quality, input materials received, and condition and includes any other quality control activities as specified in the QCP.  Ongoing problems with inadequate, incomplete, or illegible reporting will result in a change to Unconditional Acceptance.  The Contractor’s technician shall sign each Quality Control Report.

Report test results to the accuracy of the following decimal places.  When the figures to be dropped in rounding off are exactly one-half of unity in the decimal place to be retained, the value shall be rounded up or down to the nearest even number in the decimal place to be retained.

 

Single Test

Mean

Asphalt Binder Content

0.1

0.01

No. 200 (75 mm) sieve

0.1

0.01

Other sieves

1.0

0.1

Core (BSG)

0.001

0.001

 

For Item 446 mixes, in addition to quality control results on the Quality Control Report, fill out the Core Report in its entirety and include the bulk specific gravity (BSG) for each core.

For Item 448 mixes, track the Item 448 Sublot and Lot tonnages through the project and identify on the Quality Control Report each random Sublot test as to Lot number and Sublot tonnage location.  Ensure that a copy of the technician’s gradation worksheets with actual sieve weights for each Sublot sample has the Sublot/Lot identification and is submitted with each day’s Quality Control Report.  Attach computerized plant printouts representing samples tested to that day’s report, if desired by the Monitoring Team, or otherwise keep it with the quality control records.  Ensure that the technician notes on the accompanying printout in which tonnage the quality control sample was taken with accompanying test results for AC content and percent passing the No. 4 (4.75 mm) sieve.  Keep remaining printouts in the plant laboratory for the duration of the project.  Keep a copy of all quality control reports for a project in the Contractor’s plant laboratory.

C.      Department Verification Testing and Monitoring.  For Basic and Item 448 mixes, the Monitoring Team will randomly choose one Department split sample in every four production days for VA testing to confirm Contractor testing and mix control.  In addition, the Monitoring Team will sample and split, or witness sampling and splitting of one random Contractor sample in every 4 production days.  This provides two Department tests in four production days.  On larger production projects, if mix production is proven consistently acceptable by Department VA testing and the DET concurs, the District may not test the additional random sample taken or witnessed by the District monitor.  However, the District monitor must witness the Contractor split sample test to completion.

For Item 446 mixes, the District must test a minimum of five random cores in every 2 production days for Department VA testing.

For Basic and Item 448 mixes, the Monitoring Team may opt to test the Department split sample in the plant laboratory with the Contractor’s permission, according to the Contractor’s safety practices, and with the restriction of only the Contractor’s technician placing a sample in the AC Gauge.  Record the results in the District project record.  One day may be added to the above Department sample testing frequency for each day production is less than 500 tons (450 metric tons).

For all mixes, the District may increase the VA testing frequency if desired.

All Department VA test results will be given to the Contractor by a reasonable arrangement acceptable to both.  Department VA sample testing not completed in a timely manner is of no value in determining quality control testing quality and investigating problem causes.  As such, if not completed in a timely manner, Contractor tests will automatically stand.

Table 403.06-1  Department Verification Comparison

 

Percent

Asphalt Binder

Percent

Passing No. 4 (4.75mm)

BSG

Basic, other than 302[1]

±0.3

±4.0

--

302[1]

±0.4

±5.0

--

448[1]

±0.3

±4.0

--

446[2]

--

--

0.010

[1]  District mix test deviation from Contractor split.

[2]  District core test deviation from Contractor result.

 

If the Department VA tests confirm Contractor testing is within the verification tolerances, but a pattern of high or low results exist that suggests mix control is not at the JMF or field densities are inaccurately determined, then investigate with the Monitoring Team’s assistance to correct the problem to the Monitoring Team’s satisfaction.  Direct questions regarding interpretation of circumstances to the Laboratory.

D.      Contractor Tests are Verified.  Production is acceptable if:

1.       the Monitoring Team verifies the Contractor’s QCP is being fully followed; and

2.       the Department VA tests are within the limits specified in 403.06.C; and

3.       for Basic mixes, the remaining sieves do not exceed the limits of the applicable specification.

Failure on the Contractor’s part to respond and resolve Monitoring Team concerns may result in a change to Unconditional Acceptance.

Acceptance is based on Table 403.06-2.

Table 403.06-2  Mix Acceptance

Mix Type

Acceptance Tolerances or Method

Basic Mixes
(no acceptance limits stated in appropriate specification)

 

Deviation

from JMF

Range

 

Asphalt Binder Content

± 0.5%

1.0

 

No. 4 (4.75 mm) sieve

± 6%

12

Basic Mixes
(acceptance limits stated in appropriate specification)

Use acceptance limits in appropriate specification

446 Mixes

Calculate pay factor according to 446.05

448 Mixes

Calculate pay factor according to 403.08

 

E.      Contractor Tests not Verified.  If the Department VA test does not verify the accompanying Contractor test within the verification tolerances, then the Monitoring Team will investigate by notifying the Contractor immediately and by testing one additional mix sample or the remaining cores from the days or Lot in question and comparing to the accompanying Contractor test.

If the deviation between the District and Contractor test is greater than the limits in Table 403.06-3 immediately cease production until resolved.  If the deviation is less than the above limits and discrepancies continue, performs additional tests.

Table 403.06-3  Deviation Limits

Property

Mix

Limits

Asphalt Binder Content

All

± 0.5 %

No. 4 (4.75 mm) sieve

All, except 302

± 6.0%

302

± 7.0%

BSG

446

± 0.015

 

Additional tests may include any testing necessary to resolve the problem.  If the additional testing does not resolve the problem by one-half production day or 1000 tons (1000 metric tons), whichever occurs first, to the Monitoring Team’s satisfaction, stop production, if not already, until problems are resolved.  If the District testing program is confirmed by the additional tests and Monitoring Team investigation and no reason to question the original test exists, then the original District tests will stand.

After the above investigation, one of the three following actions will occur:

1.      Mix Production Compares Well to the JMF.  If the District test and investigation shows mix is actually controlled well compared to the JMF or field density is accurate in spite of the Contractor test, the District does not have to test additional samples if the Contractor testing problem is corrected.

2.      Mix Production Does Not Compare Well.  If the District tests and investigation shows lack of Contractor mix control compared to the JMF or incorrect field density, the District will test the remaining Department samples for the days or Lots represented by the original tests.  The District will use the test results to calculate the acceptance.  While working with the District, immediately take steps to correct the problem according to the QCP.  Failure to achieve a quick resolution will result in a change to Unconditional Acceptance.

3.      District Testing Problem.  If the Department testing program has a problem as confirmed by the additional testing and District review, the District will correct the problem, throw out the original test results, and take new Department samples from the samples representing the days or Lots in question for the VA tests.

F.      Contractor Removal, Restoration.  If repeated problems with poor comparison of tests are not the District’s fault; or poor comparison of Contractor tests to the JMF; or with plant operation, input materials, or any of the other requirements of Department specifications occur in a single project or successive projects, the District will request an opinion from the QCQC before notifying the Contractor of removal from Department VA.  The District will immediately notify the Contractor of the removal with a follow up letter by the DDD.  Once notified, acceptance of asphalt mixtures is by Unconditional Acceptance.  Restoration of the VA procedures may occur on a future project with a District recommendation to the QCQC based on consistent improved plant operation and mix control, a review of the Contractor problems and resolutions, and a review of the QCP by the QCQC.

403.07  Unconditional Acceptance.  If the Contractor is removed from Department VA, the following will occur.

The Contractor must bring its QCP and operation to a level acceptable to the District and QCQC before production continues.  The DET will ensure that the project C-95 (Contractor’s Prequalification Rating survey) will reflect the change to Unconditional Acceptance in all of the appropriate C-95 categories.  The Department will accept all material for Department projects from the facility under Unconditional Acceptance.  While the facility is under Unconditional Acceptance, acceptance of small quantities under the small quantities policy will not apply.

Quality control testing requirements specified in 403.05 are modified as follows:

A.     The required number of test series is a minimum of three each per production day or night.  If a production day is less than 6 hours, the Department may reduce the frequency but not less than one test series per every 3 production hours.

B.      For Basic mixes, if the variation from the JMF for one test is ±8 percent passing the No. 4 (4.75 mm) sieve or ±0.3 percent asphalt binder content, investigate and correct the problem, then resample and test.  Maintain the moving average of three tests within ±4 percent passing the No. 4 (4.75 mm) sieve and ±0.2 percent asphalt binder content.  In addition to the Quality Control Report, maintain control charts according to 441.10 for asphalt binder content and the No. 4 (4.75 mm) sieve.  If the Range difference in any three consecutive tests is greater than 0.6 percent for asphalt binder content or 10.0 percent passing the No. 4 (4.75 mm) sieve, notify the Monitoring Team.  If Range deviations as specified continue, cease production.

C.      Report each day’s testing on a Quality Control Report, according to 446.04.  The Contractor shall report all testing performed by the Contractor’s technician on the Quality Control Report.  After startup adjustments, report any plant operation changes on the Quality Control Report.  Ensure that each Quality Control Report contains technician comments as to production quality, input materials received, and condition and includes any other quality control activities required in the QCP.  The Contractor’s technician shall sign each Quality Control Report.  Attach each day’s computerized plant printouts to that day’s report.  The technician shall note on the accompanying printout in which tonnage the quality control sample was taken with accompanying test results for asphalt binder content and percent passing the No. 4 (4.75 mm) sieve.  Keep a copy of all Quality Control Reports for a project in the Contractor’s plant laboratory.

The District will monitor according to 441.06, except notification for ceasing production does not have to be in writing.  Additional samples may be obtained for Department test at any time.

For Basic mixes, if the mean of the Lot or partial Lot acceptance tests for any sieve other than the No. 4 (4.75 mm) sieve exceeds the specification limits, the pay factor is determined as follows:

Table 403.07-1  Basic Mix Pay Factors

Number of Tests

1

2

3

4

Pay Factor

0.98

0.97

0.96

0.95

 

For Item 446 mixes, the Department will test all acceptance cores.  Department core testing under Unconditional Acceptance will receive a lower testing priority than other VA projects.

For Item 448 mixes, the Department will perform acceptance sampling and testing according to 403.06 and 403.08, except the Lot size will be 5000 tons (5000 metric tons) with 1250 ton (1250 metric tons).  Sublots and acceptance samples may be taken from the roadway or plant at the Districts discretion.  Department testing under Unconditional Acceptance will receive a lower testing priority than other VA projects.

403.08  Acceptance Tables for 448 Mixes.  A Lot is considered acceptable for gradation and asphalt binder content if the deviation of the mean from the JMF and the Range is no more than the tolerances shown in Table 403.08-1.

Table 403.08-1  Deviation from the JMF and Range Tolerances[1]

Mix Property

Deviation

from JMF

(Percent)

Range

(Percent)

Asphalt Binder Content

0.4

1.0

1/2 inch (12.5 mm) sieve

6

15

No. 4 (4.75 mm) sieve

5

15

No. 8 (2.36 mm) sieve

4

15

[1]  Based on mean of four Lot Acceptance tests.

 

If the mean of the Lot acceptance tests for a particular sieve or sieves, or for asphalt binder content deviates from the JMF by more than the tolerances shown in Table 403.08-1, but falls within the tolerances shown in Table 403.08-2, then the Lot is considered reasonably acceptable and may remain in place with payment at a reduced pay factor as show in Table 403.08-2.

If the Range of the Lot acceptance tests for asphalt binder content or for any particular sieve, or sieves, exceeds the tolerance shown in Table 403.08-1, the Department will apply a pay factor of 0.95.

Table 403.08-2  448 Acceptance Schedule[1]

Mix

Property

Pay

Factor

1

Test

2

Tests

3

Tests

4

Tests

Asphalt

Binder

Content

1.00

0 to 0.80

0 to 0.57

0 to 0.46

0 to 0.40

0.98

0.81 to 0.90

0.58 to 0.64

0.47 to 0.52

0.41 to 0.45

0.94

0.91 to 1.00

0.65 to 0.71

0.53 to 0.58

0.46 to 0.50

0.85

1.01 to 1.10

0.72 to 0.78

0.59 to 0.64

0.51 to 0.55

0.70

1.11 to 1.20

0.79 to 0.85

0.65 to 0.69

0.56 to 0.60

[2]

> 1.20

> 0.85

> 0.69

> 0.60

 

 

 

 

 

 

1/2 inch

(12.5 mm)

sieve

1.00

0 to 12

0 to 8.5

0 to 6.9

0 to 6.0

0.99

13 to 14

8.6 to 9.9

7.0 to 8.1

6.1 to 7.0

0.97

15 to 16

10.0 to 11.3

8.2 to 9.2

7.1 to 8.0

0.94

17 to 18

11.4 to 12.7

9.3 to 10.4

8.1 to 9.0

0.90

19 to 20

12.8 to 14.1

10.5 to 11.5

9.1 to 10.0

[3]

> 20

> 14.1

> 11.5

> 10.0

 

 

 

 

 

 

No. 4

(4.75 mm)

sieve

1.00

0 to 10

0 to 7.1

0 to 5.8

0 to 5.0

0.99

11 to 12

7.2 to 8.5

5.9 to 6.9

5.1 to 6.0

0.97

13 to 14

8.6 to 9.9

7.0 to 8.1

6.1 to 7.0

0.94

15 to 16

10.0 to 11.3

8.2 to 9.2

7.1 to 8.0

0.90

17 to 18

11.4 to 12.7

9.3 to 10.4

8.1 to 9.0

[3]

> 18

> 12.7

> 10.4

> 9.0

 

 

 

 

 

 

No. 8

(2.36 mm)

sieve

1.00

0 to 8

0 to 5.7

0 to 4.6

0 to 4.0

0.99

9 to 10

5.8 to 7.1

4.7 to 5.8

4.1 to 5.0

0.97

11 to 12

7.2 to 8.5

5.9 to 6.9

5.1 to 6.0

0.94

13 to 14

8.6 to 9.9

7.0 to 8.1

6.1 to 7.0

0.90

15 to 16

10.0 to 11.3

8.2 to 9.2

7.1 to 8.0

[3]

> 16

> 11.3

> 9.2

> 8.0

[1]  Based on mean of Lot Acceptance tests from the JMF.

[2]  Remove and replace material.

[3]  Engineer will determine if the material may remain in place.  Pay factor for material allowed to remain in place is 0.70.

 

The Department will determine payment for the Lot by multiplying the contract unit price by the pay factor.  When two or more pay factors for a specific Lot are less than 1.00, use lowest pay factor to calculate the payment.

The Department will base acceptance of partial Lots on the mean and the Range of the results of tests on the number of samples obtained.