1、Standard Specification for Superpave Volumetric Mix Design AASHTO Designation: M 323-171 Technical Section: 2d, Proportioning of AsphaltAggregate Mixtures Release: Group 3 (August 2017) American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washin
2、gton, D.C. 20001 TS-2d M 323-1 AASHTO Standard Specification for Superpave Volumetric Mix Design AASHTO Designation: M 323-171Technical Section: 2d, Proportioning of AsphaltAggregate Mixtures Release: Group 3 (August 2017) 1. SCOPE 1.1. This specification for Superpave volumetric mix design uses agg
3、regate and mixture properties to produce job-mix formulas for asphalt mixtures. 1.2. This standard specifies minimum quality requirements for binder, aggregate, and asphalt mixtures for Superpave volumetric mix designs. 1.3. This standard may involve hazardous materials, operations, and equipment. T
4、his standard does not purport to address all of the safety concerns associated with its use. It is the responsibility of the user of this procedure to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 2. REFERENCED DOCUMENTS 2.1
5、. AASHTO Standards: M 320, Performance-Graded Asphalt Binder R 28, Accelerated Aging of Asphalt Binder Using a Pressurized Aging Vessel (PAV) R 35, Superpave Volumetric Design for Asphalt Mixtures R 59, Recovery of Asphalt Binder from Solution by Abson Method T 11, Materials Finer Than 75-m (No. 200
6、) Sieve in Mineral Aggregates by Washing T 27, Sieve Analysis of Fine and Coarse Aggregates T 164, Quantitative Extraction of Asphalt Binder from Hot Mix Asphalt (HMA) T 176, Plastic Fines in Graded Aggregates and Soils by Use of the Sand Equivalent Test T 240, Effect of Heat and Air on a Moving Fil
7、m of Asphalt Binder (Rolling Thin-Film Oven Test) T 283, Resistance of Compacted Asphalt Mixtures to Moisture-Induced Damage T 304, Uncompacted Void Content of Fine Aggregate T 308, Determining the Asphalt Binder Content of Hot Mix Asphalt (HMA) by the Ignition Method T 312, Preparing and Determinin
8、g the Density of Asphalt Mixture Specimens by Means of the Superpave Gyratory Compactor T 313, Determining the Flexural Creep Stiffness of Asphalt Binder Using the Bending Beam Rheometer (BBR) 2017 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplic
9、ation is a violation of applicable law.TS-2d M 323-2 AASHTO T 315, Determining the Rheological Properties of Asphalt Binder Using a Dynamic Shear Rheometer (DSR) T 319, Quantitative Extraction and Recovery of Asphalt Binder from Asphalt Mixtures T 335, Determining the Percentage of Fracture in Coars
10、e Aggregate 2.2. ASTM Standard: D4791, Standard Test Method for Flat Particles, Elongated Particles, or Flat and Elongated Particles in Coarse Aggregate 2.3. Asphalt Institute Publication: MS-2, Asphalt Mix Design Methods 2.4. National Asphalt Pavement Association Publication: IS 128, HMA Pavement M
11、ix Type Selection Guide 2.5. Other References: LTPP Seasonal Asphalt Concrete Pavement Temperature Models. LTPPBind 3.1, http:/ltpp- NCHRP Report 452: Recommended Use of Reclaimed Asphalt Pavement in the Superpave Mix Design Method: Technicians Manual. National Cooperative Highway Research Program P
12、roject D9-12, TRB, National Research Council, Washington, DC, 2001. 3. TERMINOLOGY 3.1. air voids (Va)the total volume of the small pockets of air between the coated aggregate particles throughout a compacted paving mixture, expressed as a percent of the bulk volume of the compacted paving mixture.
13、3.2. asphalt mixturesincludes hot mix and warm mix asphalt. 3.3. design ESALsdesign equivalent (80-kN) single-axle loads. 3.3.1. discussiondesign ESALs are the anticipated project traffic level expected on the design lane over a 20-yr period. For pavements designed for more or less than 20 yr, deter
14、mine the design ESALs for 20 yr when using this standard. 3.4. dust-to-binder ratio (P0.075/Pbe)by mass, the ratio between the percent of aggregate passing the 75-m (No. 200) sieve (P0.075) and the effective binder content (Pbe). 3.5. maximum aggregate sizeone size larger than the nomina l maximum a
15、ggregate size (Note 1). Note 1The definitions given in Sectio ns 3.7 and 3.8 apply to Superpave mixtures only and differ from the definitions published in other AASHTO standards. 3.6. nominal maximum aggregate sizeone size larger than the first sieve that retains more than 10 percent aggregate (Note
16、 1). 3.7. primary control sieve (PCS)the sieve defining the break poi nt between fine- and coarse-graded mixtures for each nominal maximum aggregate size. 3.8. reagent-grade solventa solvent meeting the level of chemical purity as to conform t o the specifications for “reagent grade” as established
17、by the Committee on Analytical Reagents of the American Chemical Society and used to extract the asphalt binder from the mixture. When asphalt 2017 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-2d M 323
18、-3 AASHTO binder is intended to be extracted and then tested for additional properties, a reagent-grade solvent must be used. Non-reagent-grade solvents may contain epoxy resins that may affect the properties of the recovered binder. In particular, certain acid-modified binders may be affected by no
19、n-reagent grade solvents. 3.9. reclaimed asphalt pavement (RAP)removed and/or processed pavement materials containing asphalt binder and aggregate. 3.10. reclaimed asphalt pavement binder ratio (RAPBR)the ratio of the RAP binder in the mixture divided by the mixtures total binder content. 3.11. void
20、s in the mineral aggregate (VMA)the volume of the intergranular void space between the aggregate particles of a compacted paving mixture that includes the air voids and the effective binder content, expressed as a percentage of the total volume of the specimen. 3.12. voids filled with asphalt (VFA)t
21、he percentage of the VMA filled with binder (the effective binder volume divided by the VMA). 4. SIGNIFICANCE AND USE 4.1. This standard may be used to select and evaluate materials for Superpave volumetric mix designs. 5. BINDER REQUIREMENTS 5.1. The binder shall be a performance-graded (PG) binder
22、, meeting the requirements of M 320, which is appropriate for the climate and traffic-loading conditions at the site of the paving project or as specified by the contract documents. 5.1.1. Determine the mean and the standard deviation of the yearly, 7-day-average, maximum pavement temperature, measu
23、red 20 mm below the pavement surface, and the mean and the standard deviation of the yearly, 1-day-minimum pavement temperature, measured at the pavement surface, at the site of the paving project. These temperatures can be determined by use of the LTPPBind 3.1 software or can be supplied by the spe
24、cifying agency. If the LTPPBind software is used, the LTPP high- and low-temperature models should be selected in the software when determining the binder grade. Often, actual site data are not available, and representative data from the nearest weather station will have to be used. 5.1.2. Select th
25、e design reliability for the high- and low-temperature performance desired. The design reliability required is established by agency policy. Note 2The selection of design reliability may be influenced by the i nitial cost of the materials and the subsequent maintenance costs. 5.1.3. Using the paveme
26、nt temperature data determined, select the minimum required PG binder that satisfies the required design reliability. 5.2. If traffic speed or the design ESALs warrant, increase the high-temperature grade by the number of grade equivalents indicated in Table 1 to account for the anticipated traffic
27、conditions at the project site. 2017 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-2d M 323-4 AASHTO Table 1Binder Selection on the Basis o f Traffic Speed and Traffic Level Design ESALsb (Million) Adju
28、stment to the High-Temperature Grade of the BinderaTraffic Load Rate StandardcSlowdStandinge25 Note 4An Agency may alter the virgin binder selection criteria from Table 2 based on the research procedures provided in Appendix X2 and field experiences. 5.3.2. Reclaimed asphalt pavement binder ratioIf
29、the agency elects to use the RAPBR method, the binder grade selected in Sections 5.1.3 and 5.2 must be adjusted according to Table 3 to account for the amount of stiffness of the RAP binder. Procedures for developing a blending chart are included in Appendix X2. Table 3Binder Selection Guidelines fo
30、r Reclaimed Asphalt Pavement (RAP) Mixtures Recommended Virgin Asphalt Binder Grade RAPBR No change in binder selection 0.25 2017 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-2d M 323-5 AASHTO ()Total1
31、00RAP RAPPb PRAPBRPb=(1) where: RAPBR = Reclaimed asphalt pavement binder ratio PbRAP = Binder content of the RAP PRAP= RAP percentage by weight of mixture PbTotal = Total binder content in the mixture 6. COMBINED AGGREGATE REQUIREMENTS 6.1. Size Requirements: 6.1.1. Nominal Maximum SizeThe combined
32、 aggregate shall have a nominal maximum aggregate size of 4.75 to 19.0 mm for asphalt pavement surface courses and no larger than 37.5 mm for asphalt pavement subsurface courses. Note 5Additional guidance on selection of the appropriate nominal ma ximum size mixture can be found in the National Asph
33、alt Pavement Associations IS 128. 6.1.2. Gradation Control PointsThe combined aggregate shall conform to the gradation requirem ents specified in Table 4 when tested according to T 11 and T 27. Table 4Aggregate Gradation Control Points Nominal Maximum Aggregate SizeControl Points (% Passing) Sieve S
34、ize, mm 37.5 mm 25.0 mm 19.0 mm 12.5 mm 9.5 mm 4.75 mm Min Max Min Max Min Max Min Max Min Max Min Max 50.0 100 37.5 90 100 100 25.0 90 90 100 100 19.0 90 90 100 100 12.5 90 90 100 100 100 9.5 90 90 100 95 100 4.75 90 90 100 2.36 15 41 19 45 23 49 28 58 32 67 1.18 30 55 0.075 0 6 1 7 2 8 2 10 2 10 6
35、 13 6.1.3. Gradation ClassificationThe combined aggregate gradation shall be classified as coarse -graded when it passes below the Primary Control Sieve (PCS) control point as defined in Table 5 (also see Figure 1). All other gradations shall be classified as fine-graded. Table 5Gradation Classifica
36、tion PCS Control Point for Mixture Nominal Maximum Aggregate Size (% Passing) Nominal maximum aggregate size 37.5 mm 25.0 mm 19.0 mm 12.5 mm 9.5 mm Primary control sieve 9.5 mm 4.75 mm 4.75 mm 2.36 mm 2.36 mm PCS control point, % passing 47 40 47 39 47 2017 by the American Association of State Highw
37、ay and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-2d M 323-6 AASHTO Figure 1Superpave Gradation Control Points for a 12.5-mm Nominal Maxim um Size Aggregate Gradation 6.2. Coarse Aggregate Angularity RequirementsThe aggregate shall meet the percent
38、age of fractured faces requirements, specified in Table 6, measured according to T 335. 6.3. Fine Aggregate Angularity RequirementsThe aggregate shall meet the uncompacted void content of fine aggregate requirements, specified in Table 6, measured according to T 304, Method A. 6.4. Sand Equivalent R
39、equirementsThe aggregate shall meet the sand equivalent (clay content) requirements, specified in Table 6, measured according to T 176. 6.5. Flat-and-Elongated RequirementsThe aggregate shall meet the fla t-and-elongated requirements, specified in Table 6, measured according to ASTM D4791, with the
40、exception that the material passing the 9.5-mm sieve and retained on the 4.75-mm sieve shall be included. The aggregate shall be measured using the ratio of 5:1, comparing the length (longest dimension) to the thickness (smallest dimension) of the aggregate particles. 6.6. When RAP is used in the mi
41、xture, the RAP aggregate shall be extracted from the RAP using a solvent extraction (T 164) or ignition oven (T 308) as specified by the agency. The RAP aggregate shall be included in determinations of gradation, coarse aggregate angularity, fine aggregate angularity, and flat-and-elongated requirem
42、ents. The sand equivalent requirements shall be waived for the RAP aggregate but shall apply to the remainder of the aggregate blend. Maximum Density LineMaximum SizeNominal Maximum SizePCS Control Point75 m 2.36 mm 9.5 mm 12.5 mm 19.0 mmSieve Opening (0.45 Power)Percent Passing0.020.040.060.080.010
43、0.00 2017 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-2d M 323-7 AASHTO Table 6Superpave Aggregate Consensus Property Requirements Design ESALsa (Million) Fractured Faces, Coarse Aggregate,c% Minimum
44、Uncompacted Void Content of Fine Aggregate, % Minimum Sand Equivalent, % Minimum Flat and Elongated,c% Maximum Depth from Surface Depth from Surface 100 mm 100 mm 100 mm 100 mm 0.3 million ESALs, and for 4.75-mm nominal maximum size mixtures, the specified VFA range shall be 66 to 77 percent. g For
45、design traffic levels 3 million ESALs, and for 9.5-mm nominal maximum size mixtures, the specified VFA range shall be 73 to 76 percent. Note 7If the aggregate gradation passe s beneath the PCS Control Point specified in Table 5, the dust-to-binder ratio range may be increased from 0.61.2 to 0.81.6 a
46、t the agencys discretion. 2017 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-2d M 323-8 AASHTO Note 8Mixtures with VMA exceeding the minimum value by more than 2 percent may be prone to flushing and rut
47、ting. Unless satisfactory experience with high VMA mixtures is available, mixtures with VMA greater than 2 percent above the minimum should be avoided. 7.3. The asphalt mixture design, when compacted according to T 312 at 7.0 0.5 percent air voids and tested in accordance with T 283, shall have a mi
48、nimum tensile strength ratio of 0.80. 8. KEYWORDS 8.1. Aggregate and mixture properties; job mix formulas; Superpave; volumetric mix design. 9. REFERENCE 9.1. NCHRP. NCHRP Report 752: Improved Mix Design, Evaluation, and Materials Management Practices for Hot Mix Asphalt with High Reclaimed Asphalt Pavement Content. National Cooperative Highway Research Program Project 9-46, TRB, National Research Council, Washington, DC, 2013. APPENDIXES (Nonmandatory Information) X1. PROCEDURES FOR DEVELOPING A BLENDING CHART X1.1. Blending of RAP binders can be accomplished by knowing the desired final
