Section 404 — Thin Lift Asphalt Concrete Pavement

Description

404.01This work consists of constructing thin lift asphalt concrete pavement using HMA or WMA.

Material

404.02Conform to the following Subsections: Antistrip additive 702.05 Asphalt binder 702.01 Asphalt concrete aggregate 703.07 Mineral filler 725.05

Construction Requirements

404.03Composition of Mix (Job- Mix Formula). (a)General. Provide a thin lift asphalt concrete pavement JMF that conforms to one of the follo wing: (1)Type I. At least 30 days before production, submit a state department of transportation thin lift asphalt concrete JMF that is used for a highway system and approved by the state department of transportation within the past 12 months. For each proposed JMF, submit a current production certification conforming to state department of transportation specifications. Submit the strength, quality, and gradation specifications for the asphalt concrete mix. Include copies of laboratory test reports that demonstrate the aggregate, asphalt binder, additive, and mix properties meet state department of transportation specifications. (2)Type II. Select JMF mix design procedure (a) or (b) from Table 404-1. For the selected design procedure, provide an asphalt concrete mixture of aggregate, asphalt binder, RAP, and additivesthat meets the applicable aggregate gradation shown in Table 703-3 for No. 4 gradation and conforms to the design parameters shown in Table 404-1 for the selected mix design procedure. In addition, conform to the requirements of (c) from Table 404-1 . Submit the strength, quality, and gradation specifications for the asphalt concrete mix. Include copies of laboratory test reports that demonstrate aggregate, asphalt binder, additive, and mix properties meet Federal or state department of transportation specifications. 354 Table 404-1

Asphalt Concrete Mix Requirements

Type II Thin Lift Asphalt Co ncrete Pavement

Design Parameters Specification

(a)Asphalt Concrete Pavement by Gyratory Mix Design Method (AASHTO M 323, AASHTO R 35, and AASHTO T 312) Gyratory compaction level (N initial, N design, N max) 6, 50, 75 Gradation (No. 4) Table 703 -3 Air voids (Va), % 5 VMA, % 16 to 21(1) VFA, % 66 to 82 Dust- to-binder ratio 0.6 to 2.0

(b)Asphalt Concrete Pavement by Marshall Mix Design Method (AASHTO T 245) Compaction, number of blows each end of test specimen 75 Gradation (No. 4) Table 703 -3 Air voids (Va), % 4 Stability, lb, minimum 2000 Flow, 0.01 in 8 to 14 VMA, % 16 to 21(1) VFA, % 66 to 82 Dust- to-binder ratio 0.6 to 2.0

(c)Moisture Susceptibility (AASHTO T 283) Tensile strength ratio, minimum 0.80 (1)Minimum verification value of design VMA is 16.5 percent . Submit the maximum specific gravity (density) of the mix as determined by AASHTO T 209. Limit the natural sand content of the thin lift asphalt concrete pavement mixture to no more than 10 percent of the total weight of aggregate in the JMF. If using WMA, apply asphalt concrete mix design requirements for HMA to the development of the WMA mix design. Provide modifications to the process required f or WMA technology. Submit modifications to the asphalt concrete mix design process according to AASHTO R 35, Appendix X.2, Special Mix Design Considerations and Practices for Warm Mix Asphalt (WMA) for approval. (b)Submittals. Conform to Subsection 401.03(d) .

(c)Verification. Allow at least 30 days for verification of each JMF. The verification process st arts when required documentation and material are received. After the JMF is verified, start asphaltconcrete mix production for the control strip. (1)Type I. (a)Aggregate gradations. The aggregate gradation is verified if the CO’s gradation on a combined asphalt concrete mix using the aggregate and RAP stockpile percentagerecommendations is within the target value gradation plus or minus the tolerance for each sieveshown in Table 404-2. 355 (b)RAP asphalt binder content and gradation. The RAP asphalt binder content results are verified if the CO’s result for each stockpile is within ±0.75 percent by total mass using AASHTO T 308. (c)Theoretical maxim um specific gravity of mixture (Gmm ). The Gmm is verified if the CO’s results are within 0.024 for AASHTO T 209. (d)Bulk specific gravity of compacted mixture (G mb). The Gmb is verified if the CO’s results are within 0.044 for AASHTO T 166. (e)Bulk specific gravity of aggregate (Gsb).

The coarse and fine Gsb is verified if

the CO’s results are within 0.038 for the combined AASHTO T 85 and AASHTO T 84. (f)VMA. The VMA result is verified if the CO’s result is 0.5 percent above the minimum specification limit. (g)VFA. The VFA result is verified if the CO’s result is within the specification limit. (h)Air voids (Va). The Va result is verified if the CO’s result at the same d esign asphalt binder content is within ±1.0 percent of the JMF design Va. (i)TSR. The TSR result is verified if the CO’s result is above the min imum specification limit. (j)Stability (Marshall mix design method only). The stability result is verified if the CO’s re sult is above the minimum specification limit. (k)Flow (Marshall mix design method only). The flow result is verified if the CO’s result is within the specification limits. (2)Type II. (a)Aggregate gradations. The aggregate gradation is verified if the CO’s gradation on a combined asphalt concrete mix using the Contractor’s aggregate and RAP stockpile percentage recommendations is within the Contractor’s target value gradation p lus or minus th e tolerance for eac h sieve shown in Table 404-2. (b)RAP asphalt binder content and gradation. The RAP asphalt binder content results are verified if the CO’s result for each stockpile is within ±0.75 percent by total mass using AASHTO T 308. (c)Theoretical maximum specific gravity of mixture (Gmm). The Gmm is verified if the CO’s results are within 0.024 for AASHTO T 209. (d)Bulk specific gravity of compacted mixture (Gmb). The Gmb is verified if the CO’s results are within 0.044 for AASHTO T 166. (e)Bulk specific gravity of aggregate (Gsb). The coarse and fine Gsb is verified if the CO’s results are within 0.038 for the combined AASHTO T 85 and AASHTO T 84. 356 (f)VMA. The VMA result is verified if the CO’s result is 0.5 percent above the minimum specification limit shown in Table 404-1 for the selected mix design procedure. (g)VFA. The VFA result is verified if the CO’s result is within the s pecification limits shown in Table 404-1 for the selected mix design procedure. (h)Air voids (V a). The V a result is verified if the CO’s result at the same design asphalt binder content is within ±1 percent of the target value shown in Table 404-1 for the selected mix design procedure. (i)TSR. The TSR result is verified if the CO’s result is above the minimum specification limit shown in Table 404-1 for the selected mix design procedure. (j)Stability (Marshall mix design method only). The stability result is verified if the CO’s result is above the minimum specification limit shown in Tabl e 404-1 for the selected mix design procedure.(k)Flow (Marshall mix design method only). The flow result is verified if the CO’s result is within the specification limits shown in Table 404-1 for the selected mix design procedure. Table 404-2 Aggregate Gradation Verification Tolerances

Sieve Size Tolerance,

Percent (±) No. 4 3.0 No. 8 3.0 No. 16 3.0 No. 30 2.0 No. 50 2.0 No. 200 1.0 Other sieves 3.0 (d)Changes and resubmissions. If a JMF is rejected or the source of material is changed, submit a new JMF for verification. Up to 30 days may be required to evaluate a change after receipt of required documentation and material. Approved changes in target values will not be applied retroactively forpayment. The CO will de duct JMF evaluation costs resulting from the following: (1)Contractor- requested changes to the approved JMF; (2)Contractor requests for more than one JMF evaluation; and (3)Additional testing necessary due to the failure of a submitted JMF.

404.04Mixing Plant. Co nform to Subsection 401.04.

404.05Equipment. Conform to Subsection 401.05.

404.06Surface Preparation. Conform to Subsection 401.06. 357 404.07 Weather Limitations. Place asphalt concrete mix on a dry, unfrozen surface when the air temperature in the shade is above 60 °F and rising. For HMA, conform to Table 404 -3. For WMA, adjust Table 404-3 minimum lay -down temperatures according to the manufacturer’s recommendations. Table 404-3 Thin Lift Asphalt Concrete Pavement Placement Temperature Road Surface Temperature, °F Minimum Lay -Down Temperature, °F(1) < 59.9 (2) 60 to 69.9 295 70 to 79.9 285 80 to 89.9 280 ≥ 90 270

(1)Do not heat the asphalt concrete mix above the temperature specified in the approved asphalt concrete mix design. (2)Do not pave.

404.08Asphalt Preparation. Conform to Subsection 401.08.

404.09Aggregate Preparation. Conform to Subsection 401.09.

404.10Mixing. Conform to Subsection 401.10.

404.11Hauling. Conform to Subsection 401.11.

404.12Production Start- Up Procedures. (a)Preparatory phase meeting. Conduct a pre -paving preparatory phase meeting according to Subsection 153.06(a) at least 3 days before the start of paving operations . Be prepared to discuss the following: (1)Calibration certification for the appropriate laboratory equipment based on the approved JMF mix design procedure. (2)Asphalt and aggregate correction factors according to AASHTO T 308 and AASHTO T 30 on Form FHWA 1640, Worksheet for Ignition Furnace Binder Correction Factor AASHTO T 308. If RAP is included as part of the JMF, provide the asphalt and aggregate correction factorsaccording to AASHTO T 30 and the FLH Addendum to AASHTO T 308 on Form FHWA 1648,Worksheet for Ignition Furnace Binder Correction Factor and Aggregate Gradation CorrectionFactor for Mixes Including RAP . (b)Control strip. Provide 7 days’ notice before starting production of an asphalt concrete mix. On the first day of production, produce sufficient asphalt concrete mix to construct a 1000-foot-long control strip, one -lane wide, and at the designated lift thickness. Construct the control strip on the project at an approved location. Construct the control strip using asphalt concrete mix production, lay- down, and compaction procedures intended for the entire mix. Stop production after construction of the control strip until the asphalt concrete mix and th e control strip are evaluated for acceptance.

(1)Mixture. Take at least three control strip asphalt concrete mix samples from the paver hopper and test according to Subsection 404.17. Asphalt concrete pavement mixtures will be evaluated based on the following:

(a)Gyratory mix design method (AASHTO M 323, AASHTO R 35, and AASHTO T 312). The asphalt concrete mix is acceptable if all test results are within specification limits for asphalt content and VMA, and the calculated pay factor for asphalt content, VMA, and gradation is 0.90 or greater.

(b)Marshall mix design method (AASHTO T 245). The asphalt concrete mix is acceptable if all test results are within specification limits for asphalt content and gradation, and the calculated pay f actor for asphalt content and gradation is 0.90 or greater.

(2)Compaction. Compact according to Subsection 404.14. Provide thin- lift nuclear density gauges calibrated according to the ASTM D2950 calibration section and within 6 months before use. Check the standard and reference on each day of use according to the ASTM D2950 standardization and reference check sections. Take nuclear gauge density readings behind each roller pass to determine the roller pattern necessary to achi eve required density. Provide documentation of passes for each roller used in the control strip. Identify breakdown and finish roller in the documentation. Provide this documentation to the CO after completion of the control strip. Take nuclear gauge densi ty readings at 10 randomly selected locations as directed. Take 5 of the 10 readings at the location designated by the CO for asphalt pavement cores. Take reading over the core location before the core is taken from pavement. Take other 5 readings at random locations on the test strip mat at locations designated by the CO. Cut and test 5 core samples at randomly selected locations as directed and as shown in Table 404-4 to verify nuclear density gauge readings. A correction factor will be applied to control strip and production density results as shown in Table 404-4, Footnote (4), if applicable. Provide the CO with documented nuclear gauge read ings correlated to core densities. Density is acceptable if the nuclear gauge density pay factor of the 10 randomly selected locations is 0.90 or greater.

(3)Control strip mat defects. Control strips that exhibit physical or visual defects will be rejected. Defects include tearing, cracking, checking, rutting, shoving, segregation, bleeding, excessive pavement roughness, or poor joints. Repeat the control strip process until an acceptable control strip is produced. Conform to Subsection 106.01 for the disposition of material in rejected control strips. Accepted control strips may remain in place and will be accepted and measured as a part of the completed pavement. Tests used for the control strip will not be included with produ ction paving results in the evaluation for payment according to Subsection 106.05. After a control strip is verified and accepted, full production may start. Use start -up procedures if resuming production after a terminatio n of production due to unsatisfactory quality according to Subsection 106.05.

404.13Placing and Finishing. Conform to Subsection 401.13.

404.14Compacting. Provide one roller each for breakdown and finish rolling. Size the rollers to achieve the required results. Operate rollers in static mode according to the manufacturer’s recommendations. Do not use diesel fuel as a release agent with rollers used to compact asphalt concrete mix. Monitor the compaction process with nuclear density gauges calibrated to the control strip density test results. Compact to the requirements of Subsection 404.17(b) . Compact the asphalt concrete mix with alternate equipment to obta in the required compaction along forms, curbs, headers, walls, and other places inaccessible to rollers. Do not cause cracking, shoving, or undue displacement. Continue compaction until surface marks are eliminated and cracks are sealed.

404.15Joints, Tri mming Edges, and Cleanup. Conform to Subsection 401.15.

404.16Pavement Straightedge Measurement. Measure the pavement surface using a 10 -foot metal straightedge at right angles and parallel to the centerline. Defective areas are deviations between the surface and the bottom of the straightedge more than ¼ inch measured between two contacts of the straightedge or deviations more than ¼ inch measured at the end of the straightedge. Correct defective areas accordi ng to Subsection 401.17. Obtain approval for the method of correction.

404.17Acceptance. See Table 404-4 for sampling, testing, and acceptance requirements. Aggregate quality properties will be evaluated under Subsections 106.02 and 106.04. Mineral filler, antistrip additives, and WMA additives will be evaluated under Subsections 106.02 and 106.03. Asphalt content, density, VMA for asphalt concrete pavement by gyratory mix design method, and gradation for asphalt concrete pavement by Marshall mix design will be evaluated under Subsectio n 106.05. Pavement roughness will be evaluated under Subsection 106.04. Asphalt binder will be evaluated under Subsections 106.03 and 106.04.

(a)Asphalt content. The upper and lower specification limits are the approved JMF target value ±0.4 percent.

(b)Density. The lower specification limit is 90.0 percent of the maximum specific gravity (density) determined according to ASTM D2950 and AASHTO T 209. The percent compaction will be determined using the average maximum specific gravity (AASHTO T 209) from all samples tested each day.

(c)Pavement roughness. The evaluation for payment will be made after defective areas are addressed. Conform to Subsection 401.17.

(d)Asphalt binder. The pay factor is determined from Table 401-5.

(e)VMA for asphalt concrete pavement by gyratory mix design method.

(1)Type I. The lower specifi cation limit is the minimum VMA as found in the state department of transportation specifications for the thin lift asphalt concrete pavement used for the approved JMF. After the JMF has been verified according to Subsection 404.03 , use the Contractor’s combined coarse and fine bulk specific gravity of aggregate G sb value from the approved JMF to calculate VMA on field produced asphalt concrete mix samples.

(2)Type II. The lower specification limit is the value shown in Table 404-1. After the JMF has been verified according to Subsection 404.03, use the Contractor’s combined coarse and fine bulk specific gravity of aggregate G sb value from the approved JMF to calculate VMA on field produced asphalt concrete mix samples.

(f)Gradation for asphalt concrete pavement by Marshall mix design method. The upper and lower specification limits are the approved JMF target values plus or minus the allowable deviations shown in Ta ble 703-2. Construction of the HMA or WMA pavement course and the in- place mat condition will be evaluated under Subsections 106.02 and 106.04. Areas of the asphalt pavement course which exhibit physical or visual defects or distresses as described in Subsection 404.12(b)(3) may require removal and replacement.

Measurement

404.18Measure the Section 404 pay items listed in the bid schedule according to Subsection 109.02 .

Payment

404.19The accepted quantities will be paid at the contract price per unit o f measurement for the Section 404 pay items listed in the bid schedule, except the asphalt concrete pavement contract price will be adjusted according to Subsection 106.05 and Table 401-7. Payment will be full compensation for the work prescribed in this Section. See Subsection 109.05. Payment for thin lift asphalt concrete pavement work will be made at a price determined by multiplying the contract price by the material pay factor. The material pay factor is calculated as follows: PF PG = Pay factor for asphalt binder. The PF PG formula is as follows: 𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃 =(𝑃𝑃𝑃𝑃1 + 𝑃𝑃𝑃𝑃2 + 𝑃𝑃𝑃𝑃3 + … .𝑃𝑃𝑃𝑃𝑛𝑛) 𝑛𝑛 where: PF# = For each sample, t he lowest pay factor determined from any test in Table 401-7. If the lowest pay factor for a sample is in reject, the sample’s pay factor is zero. n = Number of samples tested. PFmaterial = 1 + [(PF mix – 1) + (PF PG – 1)] where: PFmateria l = Material pay factor. PFmix = Pay factor for asphalt concrete pavement. PF mix is the lowest single pay factor determined for:

(a)Gyratory mix d esign m ethod Type I or II. Asphalt binder content, VMA, and density.

(b)Marshall mix d esign method Type I or II. Asphalt binder content, aggregate gradation, and density. If either the pay factor for the asphalt binder (PF PG) or the pay factor for asphalt concrete pavement (PF mix) is below 0.75, the lot for asphalt concrete pavement is in reject. Table 404-4 Sampling, Testing, and Acceptance Requirements

Material or

Product

(Subsection) Type of

Acceptance

(Subsection) Characteristic Category Test Method s

Specifications Sampling

Frequency Point of

Sampling Split

Sample Reporting

Time Remarks

Source

Asphalt

concrete aggregate (703.07 ) Measured & tested for conformance (106.04 & 105) Aggregate quality − Subsection

703.071 per type & source of material Source of material Yes Before producing Not required if using

Government-

furnish ed source

Asphalt binder

(702.01) Measured & tested for conformance (106.04) Quality − AASHTO M 320 " Asphalt supplier or mixing plant " " −

Asphalt

concrete aggregate (703.07 ) Process control (153.03 ) Gradation − AASHTO T 27 & T 11 2 per day per stockpile Crusher belt (during production) No 24 hours Not required if using a pre-crushed commercial source Table 404- 4 (continued) Sampling, Testing, and Acceptance Requirements

Material or

Product

(Subsection) Type of

Acceptance

(Subsection) Characteristic Category Test Methods

Specifications Sampling

Frequency Point of

Sampling Split

Sample Reporting

Time Remarks

Mix Design

Asphalt

concrete mixture Measured & tested for conformance (106.04 ) Gradation − AASHTO T 27 & T 11 1 per submitted mix design Stockpiles Yes 30 days before paving −

RAP asphalt

binder content − AASHTO T 308 " " " " −

RAP asphalt

Gradation − AASHTO T 30 " " " " Dry gradation, no binder removed

Bulk specific

gravity of aggregate (coarse & fine) − AASHTO T 84 & T 85 " “ " " − VMA − AASHTO R 35 " − " " − VFA − " " − " " − Air voids − AASHTO T 269 " − " " −

Marshall

stability & flow − AASHTO T 245 " − " " Only required for mixtures designed by

Marshall

mix design method

Tensile

strength ratio − AASHTO T 283 " − " " − Table 404- 4 (continued) Sampling, Testing, and Acceptance Requirements

Material or

Product

(Subsection) Type of

Acceptance

(Subsection) Characteristic Category Test Methods

Specifications Sampling

Frequency Point of

Sampling Split Sample Reporting

Time Remarks

Production Start -up (control strip)

Asphalt

concrete pavement Statistical (106.05 ) Gradation AASHTO T 30 3 minimum Paver hopper Yes 6 hours − No. 4 II No. 8 II No. 16 II No. 30 II No. 50 II No. 200 II

Other specified

sieves II

Asphalt

content(1) II AASHTO T 308 " " " " − VMA II AASHTO R 35 " " " " Only required for mixtures designed by

Gyratory mix

design method Density(2),(4),(5) II ASTM D2950 10 minimum In-place after compacting " 24 hours Locations randomly selected and witnessed by CO Density(2),(6) II AASHTO T 166 5 minimum In-place after compacting " 24 hours Locations randomly selected and witnessed by CO Table 404- 4 (continued) Sampling, Testing, and Acceptance Requirements

Material or

Product

(Subsection) Type of

Acceptance

(Subsection) Characteristic Category Test Methods

Specifications Sampling

Frequency Point of

Sampling Split Sample Reporting

Time Remarks

Production Start -up (control strip) (continued)

Asphalt

concrete pavement Measured & tested for conformance (106.04 ) Maximum specific gravity(3) − AASHTO T 209 3 minimum Paver hopper Yes 24 hours − Mix temperature − − First load & as directed thereafter Hauling vehicle before dumping or windrow before pickup No Upon completion of test −

Process control

(153.03) Density − ASTM D2950 5 minimum − No 24 hours − Table 404- 4 (continued) Sampling, Testing, and Acceptance Requirements

Material or

Product

(Subsection) Type of

Acceptance

(Subsection) Characteristic Category Test Methods

Specifications Sampling

Frequency Point of

Sampling Split

Sample Reporting

Time Remarks

Production

Asphalt

concrete pavement Measured & tested for conformance (106.04 ) Placement temperature − − First load & as directed thereafter Hauling vehicle before dumping, or windrow before pickup " Upon completion of measurement −

Maximum

specific gravity(3) − AASHTO T 209 1 per 7000 yd2 but not less than 1 per day Paver hopper Yes 24 hours Part of sample taken from paver hopper for gradation and AC content

Surface

tolerance − Straightedge measurement,

Subsection

404.16Continuously, after compaction Finished pavement surface No − −

Process control

(153.03) Gradation at the plant − AASHTO T 27 & T 11 Contractor determined Cold feed or hot bins as applicable " 24 hours −

Moisture

content of aggregates − AASHTO T 255 " Stockpile " " − Density − ASTM D2950 1 per 500 ft In-place after compacting " " − Table 404- 4 (continued) Sampling, Testing, and Acceptance Requirements

Material or

Product

(Subsection) Type of

Acceptance

(Subsection) Characteristic Category Test Methods

Specifications Sampling

Frequency Point of

Sampling Split

Sample Reporting

Time Remarks

Production (continued)

Asphalt

concrete pavement Statistical (106.05 ) Gradation

AASHTO

T 30 1 per 7000 yd2 but not less than 1 per day Paver hopper Yes 6 hours Only required for mixtures designed by

Marshall

mix design method No. 4 II No. 8 II No. 16 II No. 30 II No. 50 II No. 200 II

Other specified

sieves II

Asphalt

content(1) II AASHTO T 308 " " " " − VMA II AASHTO R 35 " " " " Only required for mixtures designed by

Gyratory

mix design method Density(7),(8) II ASTM D2950 10 per 7000 yd2 In-place after compacting " Immediate Testing witnessed by CO Table 404- 4 (continued) Sampling, Testing, and Acceptance Requirements

Material or Product

(Subsection) Type of

Acceptance

(Subsection) Characteristic Category Test Methods

Specifications Sampling

Frequency Point of

Sampling Split

Sample Reporting

Time Remarks

Finished Product

Asphalt concrete

mixture pavement surface Measured & tested for conformance (106.04 ) Type IV straightedge (surface tolerance) – Straightedge measurement , Subsection 404.16 – Subsection

404.16– 24 hours –

(1)Use AASHTO T 308, Method A. Calculate the asphalt binder content by weighing the sample before and after the burn using a calibrated external balance.

(2)Take nuclear gauge density readings according to ASTM D2950. Set nuclear gauge readings to 1 minute and the layer thick ness to 1 inch. Take 5 of the 10 readings at the location designated by CO for asphalt pavement cores. Take reading over the core location before the core is taken. Take other 5 readings at random locations on the test strip mat at locations designated by CO. For calculation of percent compaction (percent of maximum density), use the average of the three loose mix samples taken during the test strip.

(3)Cut two 6 -inch diameter side by side cores. Remove them with a core retriever and fill and compact the core holes with the approved thin lift asphalt concrete mixture. Label the cores and protect them from damage due to handling and temperature. Submit one core for verification testing. Dry the other core to constant mass at 125±5 °F or vacuum dry it accord ing to ASTM D7227 before performing the core density and measuring the thickness. Use 62.245 pounds per cubic foot to convert specific gravity to density. Use core results to verify control strip nuclear density gauge readings.

(4)Calculate theoretical ma ximum specific gravity according to AASHTO T 209. Use 62.245 pounds per cubic foot to convert specific gravity to density. Compare the core density to the corresponding nuclear gauge reading. Subtract corresponding nuclear density gauge reading from core density value. Do this for all 5 asphalt pavement core nuclear density gauge reading pairs. Determine the average correction factor by averaging the differences of the 5 pairs . This will be the correction factor applied to the nuclear density gauge readings for the test strip and during production.

(5)Use the developed correction factor and apply it to the 10 nuclear density readings taken for the test strip. Use the cor rected density readings to determine the pay factor for density for the test strip.

(6)Do not use the supplemental procedure for mixtures containing porous aggregate (dry back method of AASHTO T 209).

(7)After production paving has begun, use the average maximum specific gravity value (AASHTO T 209) for each day to adjust the percent compa ction for the in - place density readings taken by ASTM D2950 that represent that day’s paving

(8)The average in -place density of the 10 locations will be considered the in- place density of that 7000 -square yard lot of thin lift asphalt concrete pavement and will be used for acceptance purposes. Report as percent compaction ( percent of maximum density)