necessary equipment and qualified personnel i ncluding at least one certified Asphalt Field and Compaction Technician at each project during paving operations. Additionally, a certified Asphalt Field and Compaction Technician with certification to perform nuclear density testing of asphalt pavementss hall perform all testing necessary to assure compaction of the asphalt meets specification requirements. The Contractor, shall design a workable Quality Control Plan, detailing the type and frequency of sampling and testing deemed necessary to measure and control the magnitude of the various properties of the asphalt governed by these specifications. This plan, prepared in accordance with MP 401.03.50 shall be submitted to the Engineer for review prior to production of material under this specif ication.
401.6.2 -Job Mix Formula (JMF) Field Verification : For each JMF, a mix design field verification shall be conducted during the first days of plant production. For Marshall designs, the verification shall be in accordance with the guidelines established in MP 401.02.27. For Superpave, designs it shall be in accordance with MP 401.02.29. The field verification is for the purpose of demonstrating that the JMF can be produced within the specified tolerances set forth in the MP. If t he mix cannot be produced within these requirements, a new mix design will be required.
401.6.3 -Quality Control Testing Requirements: After the JMF design field verification has been successfully completed, sampling frequency and test requirements for quality control shall be as set forth in MP 401.02.27 for Marshall designs and MP 401.02.29 for Superpave designs. If the Division determines that a mix cannot be consistently produced within the tolerance limits of the specified design properties, approval of the mix may be revoked and the contractor will be required to provide a new mix design.
401.6.4 -Compaction : Projects shall be tested for compaction in accordance with the Lot - by-Lot test method described in Section 401.6.4.2 if the project limits meet all of the following requirements:
If a project does not meet the above criteria, testing for compaction shall be in accordance with the Rollerpass test method described in Section 401.6.4.3. In addition, areas of Trench Paving, Pavement Widening, and Pavement Repairs shall be tested in accordance with the Rollerpass test method or to the satisfaction of the Engineer. When asphalt is placed in areas that require a non -uniform thickness and tapers to a thin edge including patch and level and scratch, acceptance testing of the material is not required. Compaction shall be accomplished with a minimum of eight (8) roller passes prior to reaching the temperature specified in section 401.10.4. A pass shall be defined as the entire roller traversing a spot on the pavement. Compaction shal l be performed by a three -wheel (steel) roller or pneumatic -tire roller. Acceptance testing is not required on areas which are too narrow to be compacted with the roller use for the mainline paving, as defined in the contractor’s QC plan; such areas shal l be compacted to the satisfaction of the Engineer.
167 401.6.4.1 -Density Testing : All Gauge standardization procedures, calibration procedures and all Density testing conducted shall be in accordance with AASHTO T355 - Standard Method of Test for In -Place Density of Asphalt Mixtures by Nuclear Methods. Testing shall be conducted in the backscatter position and follow AASHTO T355 with the exception that no gauge rotation will be required. All gauge tests shall be conducted with the source end of the gauge in the direction of paving. The Gauges used for both QC and QA, shall also have a gauge comparison tested as prescribed in section 401.6.4.1.1.
401.6.4.1.1 -Gauge Comparison: For purposes of an accurate comparison, nuclear gauges used for QC and QA shall be compared using the following procedure. If an alternate gauge is brought to the project, repeat the following procedure. Note, this process is required for informational purposes however d ensity readings for Acceptance testing will not be adjusted to compensate for any differences in readings between gauges. The gauge used for the Contractor’s quality control testing shall be compared with the gauge used for the Division’s verification testing at the same locations.
position at three randomly located positions within the initial 500 feet of paving.
minimum of one ( 1) foot from the edge of the pavement.
readings exceed this range, perform a new set of five readings. A gauge should not be used if the repeatabili ty of the gauge is not within this range.
be used for QC and QA. The Contractor shall take note of this difference whilst performing QC testing. All documentation shall c onsist of original wet density readings as shown on the gauge, no offset is permitted to be entered into the gauge.
401.6.4.2 -Lot-by-Lot Testing: Density of the traveled lanes, shoulders, and Longitudinal Join t will be accepted in the field on a lot by lot basis. Lots will be established cumulatively and will be specific for each JMF.A normal lot size shall not exceed 1000 linear feet of paving, unless operational conditions or project size dictates otherwise. Each lot shall consist of five equal sublots. A standard sublot shall be 200 linear feet . Sublots shall be tested with randomly located nuclear density tests . If the remaining footage of the final two lots of a project combine to be less than 2000 linear feet following the following:
length into a single lot and , divide its leng th into five equal sublots;
length into two equal lots with five equal sublots in each lot .
Breakdowns or stoppages of short periods due to such causes as weather or equipment failure will not be considered as reason to adjust the lot size. The original lot will be continued when work resumes. Relative density shall be calculated based on the Maximum Specific gravity from the Division approved JMF or the Maximum Spec ific Gravity established under section 401.6.2, Job Mix Formula Verification, whichever is more recently established.
168 401.6.4.2.1 -Mat Density: Compaction testing for the mat density shall be performed for all traveled lanes and shoulders and will be evaluated based on an Upper Specification Limit (USL) of 97.0% relative density and a Lower Specification Limit (LSL) of 93.0% relative density. The average mat density of the Lot shall be calculated as the average of the sublot results. Acceptance of Ma t Density shall be in accordance with Section
401.13.3
401.6.4.2.2 -Joint Density: Longitudinal joint density testing shall be performed on all constructed joints between traveled lanes. Testing of a longitudinal joint constructed between a travel lane and a shoulder is not required. Joint density testing is not required until both lanes of the joint are constructed. The first lane constructed shall be referred to as the cold side and the second lane shall be referred to as the hot side. Joint densit y testing shall be conducted on the hot side, with the gauge positioned four (4) inches from the constructed joint. Only longitudinal joints constructed on the surface course shall be subject to density testing. Longitudinal joint density testing shall b e accepted in the field on a lot by lot basis as described in Section 401.6.4.1. Compaction testing for the joint density will be evaluated based on an Upper Specification Limit (USL) of 97.0% relative density and a Lower Specification Limit (LSL) of 90.0 % relative density. The average joint density of the Lot shall be calculated as the average of the sublot results. Acceptance of joint density shall be in accordance with Section 401.13.3.
401.6.4.3 -Roller Pass Testing: A Rollerpass Control Section sh all be completed on a daily basis, when roadway conditions change where they would affect the compaction effort, or when the Engineer determines the current rollerpass is unsatisfactory. A rollerpass shall be established prior to the mat reaching the tem perature specified in If a project does not meet the criteria in section 401.6.4, testing for compaction shall be in accordance with the rollerpass test method described in Section 401.6.4.2. In addition, areas of trench paving, pavem ent widening, and pavement repairs shall be tested in accordance with the rollerpass test method or to the satisfaction of the Engineer. A rollerpass shall be conducted in the following manor:
transverse construction joint. If an additional rollerpass is required by the Engineer conduct it immediately.
roller traversing a spot on the pavement) to the roadway, then conduct two randomly located nuclear density testing within the section; record the results, the average, and the mat temperature at each test location.
locations; record the results, the average, and the mat temperature at each test location.
kg/m3 increase occurs between the average of two sets of readings, (b) the density of the material exceeds 97.0% Gmm, (c) one of the two test location “breaks over” (i.e. shows a decrease in density) after exceeding 92.0% of Gmm, or (d) the temperature of the mat has fallen below 175 °F.
169 5. Compute the Percent of Gmm using the average of t he two readings and record on the worksheet.
If the mat begins to show signs of distress (such as excessive surface aggregate breakage or mat cracking) before reaching 175 °F, then discontinue rolling and record the number of roller passes completed befo re the stress signs occurred. If a tender mix, as defined in Section 3.3, is encountered the Contractor may be allowed to continue rolling at lower temperatures if it can be demonstrated that additional densification can be achieved at a lower temperature without causing any pavement distress. Once the control section is completed, the density shall be equal to or greater than 92.0% of Gmm. If the density does not meet 92% of Gmm, repeat the procedure above immediately. If after two control sections the density still does not meet 92% of Gmm, contractor shall apply the number of passes associated with the highest percent density, minimum of 8 passes, unless the Engineer determines more appropriate means. To help with this decision, an evaluation may be m ade of the existing pavement condition and any density test results obtained prior to construction of the test section will be reviewed. If the density within the control section meets 92% of Gmm conduct a proving section in the proceeding 1000 feet. Wit hin the proving section, apply the established number of passes and conduct five randomly located nuclear density tests. The average of these five tests shall exceed a minimum density of 92% Gmm and be within ±50.0 kg/m3 of the average wet density determi ned in the Rollerpass control section. If this is not achieved a new rollerpass section shall be conducted. All data shall be submitted the Engineer on associated Rollerpass forms.
401.7 -VERIFICATION TESTING : 401.7.1 -Acceptance Testing of Asphalt Concrete: Acceptance testing of asphalt is the responsibility of the Division. For Superpave mixes, the acceptance sampling and testing requirements for the mixture shall be as set forth in MP 401.02.29.
401.7.2 -Surface Tolerance: Final smoothness testing of all new Asphalt surfaces shall be in accordance with Section 720. When compaction is completed on the course, it shall present a uniform surface, true line and grade, conforming to the cross section shown on the Plans. When tested with a straightedge of approximately ten ( 10) feet in length and a template of the specified dimensions, the finished base course shall not show a deviation greater than ¼ inch and the finished wearing course shall not show a deviation from the required surface greater than 3/16 inch. The Contracto r shall provide the straightedge and template for checking the surfaces and an employee to use them under the direction of the Engineer. Any irregularity of the surface exceeding the limits specified shall be corrected. Depressions which develop after th e initial rolling shall be corrected by loosening the mixture and adding new material. High places shall be corrected by removing excess material. Areas of completed courses found to be defective shall be removed and replaced with approved mixtures laid in accordance with these specifications, and no additional compensation will be allowed for materials used or work involved in replacing defective areas.
401.7.3 -Lot by Lot Compaction : Acceptance testing of mat and joint density is the responsibility of the Division. The Division will conduct density acceptance testing in
170 accordance with section 401.6.4.1. Acceptance activities will be accomplished by conducting testing completely independent of the quality control activities.
401.7.3.1 -Mat Densit y: Within a lot of materials offered by the contractor for acceptance, locate one random test. Perform a single 1 -minute test in accordance with section 401.6.4.1. Compare the density to the specification range. If the value is within the range, the lo t is accepted for density. If the density result is outside the specification range, divide the lot into five equal sublots and randomly locate a test site within each sublot. Average the five sublot results and utilize section 401.13.3 to determine any required price adjustments.
401.7.3.2 -Joint Density: If a joint density lot is to be tested, it will be tested with the corresponding Mat lot. Testing of a joint density lot shall follow section 401.7.3.1.
401.7.4 -Thickness: When a uniform thickness of three (3) inches or more is specified, excluding resurfacing, cores shall be taken to verify the thickness of the compacted pavement. Cores will be taken by the Division at random locations. The sampling frequency shall be approximately five cores per 2,000 feet of two -lane construction, except that the sampling frequency shall normally be limited to a minimum of five and a maximum of 50 cores per project. The Division may elect to waive coring for short projects of less th an 1,000 feet in length or for projects where a paving mat of uniform thickness cannot be expected (for example: tapered paving mats or pavement widening projects). The Division may also elect to take additional cores when needed to resolve problems related to pavement thickness. The thickness shall be considered acceptable if one or both of the following criteria are met:
statistically significant at the 95% confidence level. (Standard one tail “t” test at 0.05 significance).
The calculated ‘t’ value shall be less than or equal to the standard ‘t’ value at the 95% confidence level. The method for calculating Criteria ‘B’, shall be as follows:
95tt
Where: 95t = value from standard “t” table for 95% confidence level
txx sns=−−1
xs = specified thickness = average thickness n = number of samples
sxx n n=− − 22 1()
x = individual core thickness