611 - HOT MIX ASPHALT (HMA)-COMMERCIAL GRADE
600-63 If RAP or RAS is used, inform the Engineer as to the source and type of RAP and RAS. Provide RAP that
is reasonably free of contamination, uniform in composition (similar to RAP gradation shown on mix design) and has passed through a 2 ¼" screen or grizzly. The Engin eer will accept the RAP and RAS based on a visual inspection. The Engineer may approve the use of an asphalt mixture (listed in TABLE 611-2 ) that is produced, tested and complies with SECTION 602 . If used, QC/QA testing is required.
2.TABLE 611-2 , Mix Design Requirements. TABLE 611-2: MIX DESIGN REQUIREMENTS (Master Grad ing Limits and VMA) Nominal Maximum Size & Mix Designation Percent Retained - Square Mesh Sieves Min. VMA (%)1" 3/4 " 1/2 " 3/8 " No. 4 No. 8 No. 200 SM-9.5A 0 0-10 10 min. 33-53 90.0-98.0 14.5 SR-9.5A 0-2 0-10 10 min. 33-53 90.0-98.0 14.5 SM-9.5T 0 0-10 10 min. 53-68 90.0-98.0 14.5 SR-9.5T 0-2 0-10 10 min. 53-68 90.0-98.0 14.5 SM-12.5A 0 0-10 10 min. 42-61 90.0-98.0 13.5 SR-12.5A 0-2 0-10 10 min. 42-61 90.0-98.0 13.5 SM-19A 0 0-10 10 min. 51-65 92.0-98.0 13.0 SR-19A 0-2 0-10 10 min. 51-65 92.0-98.0 13.0 Meet the minimum VMA requirements with design only. Use an air void target of 4% (at N des) to establish binder content. Using the combined gradation (RAP and RAS, if any, and virgin aggr egate), select a single point for each sieve within the master gradin g limits and the No. 16, No. 30, No. 50 and No. 100 sieves. Also, provide the combined virgin aggregate gradation. When controlling a virgin mix by cold feed gradation testing, apply single point tolerances in TABLE
611-3 to the design single points for the virgin aggregate. Do not ex ceed the tolerances for the Master
Grading Limits. When controlling a mix that contains RAP or RAS by cold feed virgin gradation testing, apply single point tolerances in TABLE 611-3 to the design single points for the virgin aggregate. The tolerances may exceed the Master Grading Limits. If RAP is used, calculate the Effective Specific Gravity (G se) of the RAP as shown in subsection 5.10.4 – Calculations for the Marshall Mix Design of Bituminous Mixtures, Part V and used as the G sb of the RAP. If RAS is used, calculate the Effective Specific Gravity (G se) of the RAS as shown in subsection 5.10.4, Part V and use as the G sb of the RAS. TABLE 611-3: SING LE POINT TOLERANCES Nominal Maximum Size & Mix Designation Percent Retained - Square Mesh Sieves 3/8" No. 4 No. 8 No. 16 No. 30 No. 50 No. 100 No. 200 SM-9.5A or SR-9.5A ±5 ±5 ±5 ±4 ±4 ±3 ±2 SM-9.5T or SR-9.5T ±6 ±5 ±5 ±4 ±3 ±3 ±2 SM-12.5A or SR-12.5A ±6 ±6 ±5 ±5 ±4 ±4 ±3 ±2 SM-19A or SR-19A ±6 ±6 ±5 ±5 ±4 ±4 ±4 ±2 Comply with the certification requirements for the appr opriate categories listed in the Policy and Procedure Manual for the Certified Inspection and Testing Training (CIT2) Program. Use calibrated testing equipment with prescribed procedures in the KDOT Construction Manual, Part V, Section 5.2.7. 611 - HOT MIX ASPHALT (HMA)-COMMERCIAL GRADE
600-64 d. Process Control. Prior to making a single point or prop ortion change, receive approval from the
Engineer. Depending upon the change, the Engineer may require another mix design before granting approval. On the first Lot only of production of any mix designation, any gradation penalty for the entire Lot will be assessed on the basis of the revised design job-mix (if any), provided no change in asphalt content is required as a result of the revision. For changes made in the design job-mix on subsequent Lots, computation of adjusted payment will not be retroactive within the Lots. Make any gradation change for the Lot before starting the gradation testing for that Lot. During mix production on non-QC/QA projects, the Engineer may conduct tests (randomly located) to verify compliance with the approved mix design, and make adjustments to the binder content (Note: Plant produced mix may have a lower VMA and require a reduction in binder content.). On projects with less than 500 tons of commercial grade asphalt mixture, testing (QC/QA or cold-feed gradations) is at the Engineer’s discretion. On projects with 500 tons or more, testing of the asphalt mixture is required: The Engineer will test the combined virgin gradatio n at a frequency of 1 test for each 500 ton Lot or fraction thereof. On projects with more than 2000 tons of HMA–Co mmercial Grade mixture the Contractor may request the lot be increased to 750 ton provided the following criteria are met: The plant is producing more than 500 tons of HMA–Commercial Grade mixture per day; Previous 3 consecutive lots were produced without penalty; and Provide immediate notification of lot size change to the Engineer any time a change is made. If any lot fails to meet all of the above criteria, the lot size shall resort to 500 tons until such time that the aforementioned criteria are met. Or, the Contractor and Engineer will test (QC/QA respectively) the asphalt mixture according to the testing requirements and frequenc ies in Part V, Appendix B. KDOT will perform tests at the Contractor’s lab or at a location agreed to by the Engineer and Contractor. Testing will be completed and the results reported to the Cont ractor within 24 hours. If the test results indicate there is non-compliant material, make the appropriate adjustment s to the mix proportions to comply with the approved mix design.
e.Suspension of Mixture Production. If the results of 2 consecutive cold-feed gradation tests fail to meet the single point tolerances, or QC/Q A test results fail to comply with SECTION 602 , suspend the production of that mix pending satisfactory results of a pre-production samp le. Such suspension will constitute Lot termination.
f.Additives. Provide a method for the Engineer to continua lly monitor the percent of each additive being added. When more than 25% of the mix is comprised of siliceous virgin aggregates and/or RAP, add anti-strip to the mix. The minimum amount of anti-strip required in the mix is 0.01% for every percent of natural sand and RAP in the mix. Thus, if 25% natural sand and 10% RAP is in a mix, then 0.35% anti-strip by weight of virgin asphalt binder is required in the mix. If during production, the TSR values (both KDOT and Co ntractor) exceed 85%, then the Contractor and the DME, working together, may decide on a lower amount of anti-strip. Provide Warm Mix Asphalt (WMA) additives or processes that comply with DIVISION 1200 . The Contractor is permitted to use WMA unless otherwise shown on the plans. For mixes containing Warm Mix Asphalt (WMA) ad ditives, submit for the Engineer’s review and approval, the additive or process used, the recommended rate of application, and the temperature ranges for mixing and compaction. Mixing temperature range is provided by the Asphalt Binder Supplier. When using WMA, the mixing temperature may be reduced no more than 30 oF for WMA water foaming processes, and no more than 70oF for WMA chemical and organic additives. The minimum mixing temperature for WMA is 220oF. 611.3 CONSTRUCTION REQUIREMENTS
a.General. Prepare the road surface according to subsection 602.4b . 611 - HOT MIX ASPHALT (HMA)-COMMERCIAL GRADE
600-65 Use equipment that complies with DIVISION 150 to produce, haul, spread and compact the HMA-
Commercial Grade mixture. Lift Thickness. Except for leveling courses or when shown otherwise in the Contract Documents, TABLE
602-9 applies. The Engineer may adjust lift thickness to utilize the most efficient method of acquiring specified
density and surface quality. The minimum lift thickness fo r any HMA mixture is 3 times the nominal maximum aggregate size, unless otherwise designated in the Contract Documents or approved by the Engineer. TABLE 602-9: NOMINAL COMPACTED THICKNESS Lift Maximum Nominal Compacted Thickness Surface 2 inches Base 4 inches Use a minimum of 2 rollers to compact the mixture to the maximum density before the mixture temperature falls below 175°F. When using WMA, achieve the maximum density before the temperature of the WMA falls below 165°F. Do not crush the aggregate. On incidental or miscellaneous work, the Engineer may waive the minimum roller requirement if conditions warrant. Roller ma rks may be removed with a self-propelled static roller when the pavement surface temperature falls below 175°F or 165°F for WMA, roller ma rks may be removed from the mat with a self-propelled static steel roller.
b.Weather Limitations. Do not place asphalt mixtures on any wet or frozen surface or when weather conditions otherwise prevent the proper handling and finishing of the mixture. Only place asphalt mixtures when e ither the ambient air temperature or the road surface temperature is equal to or greater than that shown in TABLE 611-4 . TABLE 611-4: ASPHALT PLACEME NT TEMPERATURE LIMITATIONS Paving Course Thickness (inches) Air Temperature (ºF) Surface Temperature (ºF) HMA WMA Foam WMA Chem HMA WMA Foam WMA Chem Surface All 50 45 40 55 50 45 Subsurface <1.5 50 45 40 55 50 45 Subsurface ≥1.5 and < 3 40 35 30 45 40 35 Subsurface ≥ 3 30 30 30 35 32 32
c.Pavement Smoothness. Evaluate pavement smoothness according to SECTION 603 and the following: Excluding side roads, entrances an d non-traffic areas, the Engineer ma y test the completed surface with a 10 foot straightedge, and the maximum a llowable surface variation is 3/16 inch in 10 feet. Correct areas that exceed the allowable variation as directed by the Engineer. HMA Commercial Grade is not eligible for pay adjustments. 611.4 MEASUREMENT AND PAYMENT The Engineer will measure HMA-Comm ercial Grade and HMA-Commercial Grade (Patching) by the ton. Payment for "HMA-Commercial Grade (Class*)" at the contract unit prices is full compensation for the specified work (including emulsified asphalt for tack). Payment for and "HMA-Commercial Grade (Class *) (Patching)" includes all excavation, compaction of subgrade or subbase if required, disposal of waste material and all material (including emulsified asphalt for tack), all labor, equipment, tools, supplies, incidentals and mobilization necessary to complete the work. If the gradation test results or air void test results indi cate there is non-compliant material, the Engineer will compute and assess either an Aggregate Price Adjustment or an Air Void Price Adjustment that will be an item added to the contract.
1.Aggregate Price Adjustment. Use TABLE 611-5 , on each Lot of asphalt mixture represented by non- compliant cold-feed gradation (acceptance) tests: Determine the absolute value of the deviation be tween the acceptance test re sults (rounded to the nearest 0.01%) and the design virgin aggregate single point for the No. 4, No. 8, No. 30 and the No 200 pay sieves. Use the 1 Test Column in TABLE 611-5 to determine payment for the Lot. Use the deviation from the sieve that produces the greatest price adjustment.
Source: Kansas Standard Specifications for State Road and Bridge Construction, 2015 Edition. Pages 300–302 of 978.