1、Standard Practice for Asphalt Additives and Modifiers AASHTO Designation: R 15-00 (2012) American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 20001 TS-2b R 15-1 AASHTO Standard Practice for Asphalt Additives and Modifiers AASHTO
2、 Designation: R 15-00 (2012) 1. SCOPE 1.1. This standard practice covers the laboratory testing required to evaluate asphalt additives and modifiers in both neat asphalt and in asphalt-aggregate hot mixtures. The terms “additive” and “modifier” are used interchangeably and are broadly interpreted to
3、 include any materials added to asphalt binder in minor amounts, other than mineral fillers, sand, and aggregates, whose purported effect is to improve the performance and service life of pavements or maintenance materials by improving the properties of the asphalt binder or hot mix asphalt, or both
4、. 1.2. Following is a list of the common purposes for which an additive/modifier may be added: 1.2.1. Anti-Rutting (permanent deformation). 1.2.2. Anti-Cracking. 1.2.2.1. Thermal Cracking (low-temperature cracking, thermal-fatigue cracking). 1.2.2.2. Load-Associated Fatigue Cracking. 1.2.3. Anti-Str
5、ippingMoisture susceptibility of the asphalt-aggregate bond. 1.2.4. Antioxidants. 1.2.5. Recycling (not included). Recycling is omitted from this standard practice. It is felt that consideration of the various characteristics of the material from the pavement to be recycled and formulation of the re
6、cycle mix are so involved as to make inclusion of recycling in this standard practice cumbersome and impractical. 1.3. The values stated in SI units are to be regarded as the standard. 2. REFERENCED DOCUMENTS 2.1. AASHTO Standards: 2.1.1. Asphalt Binders: M 320, Performance-Graded Asphalt Binder R 2
7、8, Accelerated Aging of Asphalt Binder Using a Pressurized Aging Vessel (PAV) R 29, Grading or Verifying the Performance Grade (PG) of an Asphalt Binder R 66, Sampling Asphalt Materials T 44, Solubility of Bituminous Materials T 48, Flash and Fire Points by Cleveland Open Cup T 228, Specific Gravity
8、 of Semi-Solid Asphalt Materials 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2b R 15-2 AASHTO T 240, Effect of Heat and Air on a Moving Film of Asphalt Binder (Rolling Thin-Film Oven Test) T 313,
9、Determining the Flexural Creep Stiffness of Asphalt Binder Using the Bending Beam Rheometer (BBR) T 314, Determining the Fracture Properties of Asphalt Binder in Direct Tension (DT) T 315, Determining the Rheological Properties of Asphalt Binder Using a Dynamic Shear Rheometer (DSR) T 316, Viscosity
10、 Determination of Asphalt Binder Using Rotational Viscometer 2.1.2. Aggregates: T 2, Sampling of Aggregates T 11, Materials Finer Than 75-m (No. 200) Sieve in Mineral Aggregates by Washing T 27, Sieve Analysis of Fine and Coarse Aggregates T 37, Sieve Analysis of Mineral Filler for Hot Mix Asphalt (
11、HMA) T 71, Effect of Organic Impurities in Fine Aggregate on Strength of Mortar T 84, Specific Gravity and Absorption of Fine Aggregate T 85, Specific Gravity and Absorption of Coarse Aggregate T 133, Density of Hydraulic Cement T 248, Reducing Samples of Aggregate to Testing Size 2.1.3. Mixtures: M
12、 323, Superpave Volumetric Mix Design R 30, Mixture Conditioning of Hot Mix Asphalt (HMA) R 35, Superpave Volumetric Design for Asphalt Mixtures T 166, Bulk Specific Gravity (Gmb) of Compacted Hot Mix Asphalt (HMA) Using Saturated Surface-Dry Specimens T 209, Theoretical Maximum Specific Gravity (Gm
13、m) and Density of Hot Mix Asphalt (HMA) T 269, Percent Air Voids in Compacted Dense and Open Asphalt Mixtures T 275, Bulk Specific Gravity (Gmb) of Compacted Hot Mix Asphalt (HMA) Using Paraffin-Coated Specimens T 283, Resistance of Compacted Asphalt Mixtures to Moisture-Induced Damage T 312, Prepar
14、ing and Determining the Density of Asphalt Mixture Specimens by Means of the Superpave Gyratory Compactor T 320, Determining the Permanent Shear Strain and Stiffness of Asphalt Mixtures Using the Superpave Shear Tester (SST) TP 31, Determining the Resilient Modulus of Bituminous Mixtures by Indirect
15、 Tension12.2. ASTM Standards: 2.2.1. Binders: D95, Standard Test Method for Water in Petroleum Products and Bituminous Materials by Distillation D3407, Standard Test Methods for Joint Sealants, Hot-Poured, for Concrete and Asphalt Pavements (Withdrawn 1996) D3570, Test Method for Viscosity of Bitumi
16、nous Materials with a Sliding Plate Microviscometer (Withdrawn 1986) 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2b R 15-3 AASHTO 2.2.2. Mixtures: D4123, Standard Test Method for Indirect Tension
17、Test for Resilient Modulus of Bituminous Mixtures (Withdrawn 2003) 2.3. Other Methods: NCHRP Report 274, Use of Anti-Stripping Additives in Asphaltic Concrete MixturesLaboratory Phase, Transportation Research Board, Washington, DC, December 1984 FHWA/RD-87/001, Investigation of Asphalt Additives, FH
18、WA, McLean, VA, June 1987 FHWA/TX-85/347/1, Asphalt-Rubber Binder Laboratory Performance, Texas State Department of Highways and Public Transportation, Austin, TX, August 1985 NCHRP Report 268, Influence of Asphalt Temperature Susceptibility on Pavement Construction and Performance, Transportation R
19、esearch Board, Washington, DC, December 1983 3. SUMMARY OF METHOD 3.1. The testing is divided into two phases. Phase I tests the modified binder (with tests of appropriate unmodified controls), while Phase II tests the modified hot mix asphalt. The purpose of dividing the testing into two phases is
20、to use the faster and easier tests of Phase I as a screening method. If an asphalt additive or modifier shows no promise in Phase I, there may be no need to continue to Phase II. This, of course, would not apply if the additive/modifier interacts specifically with the aggregate, e.g., in the case of
21、 anti-stripping agents. 4. SIGNIFICANCE AND USE 4.1. This standard practice details the tests and procedure for evaluating asphalt modifiers to be used for paving. The modified asphalt binder is compared, as is appropriate, either with the same asphalt binder unmodified or with asphalt binder from t
22、he same base crude refined to a specification grade mimicking the specification-defining properties of the modified asphalt binder as closely as possible. In most respects the evaluation procedures are those desirable for an unmodified asphalt binder. Both modified asphalt binder and hot mix asphalt
23、 using modified asphalt binders are evaluated. Performance-based testing is emphasized. The procedures go beyond those that would be desirable for unmodified asphalt binder in that unmodified control asphalt binders are used and tested specifically for those properties to be enhanced by the modifier
24、. If testing (at appropriate additive levels) indicates that the functional purpose of the additive is not fulfilled, testing of the additive may be terminated. If any of the other important performance properties of the modified asphalt binder are either unsatisfactory or significantly degraded, an
25、d cannot be remedied by, e.g., further modification, evaluation of the modifier may likewise be terminated. If the results of evaluation according to this standard practice are positive, small-scale field trials and economic cost-benefit analysis may be warranted. If the additive/modifier is being p
26、romoted by a supplier to a customer or evaluating laboratory, e.g., a governmental agency, a suggested list of information to be provided by the supplier to such a customer/evaluator is provided in Appendix X1. 5. CHOICE OF CONTROL SAMPLES 5.1. Control samples may be chosen for three purposes. Type
27、A control samples are used for the most general evaluation of additive/modifiers. Type B is used when the supplier believes that his 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2b R 15-4 AASHTO ad
28、ditive/modifier is useful under rather specific circumstances. Type C is used in evaluating an additive/modifier for a specific paving project. A minimum of three samples, i.e., three hot mix asphalt and their corresponding neat asphalt binders, which are commonly used as paving materials, must be c
29、hosen. 5.1.1. Type AHot mix asphalt and their corresponding neat asphalt binders spanning the range of those typically used throughout the United States may be chosen. It is recommended that the additive manufacturer obtain representative hot mix asphalt designs and constituent materials currently b
30、eing produced for and approved by three state highway administrations. Depending upon the purpose of the additive, the manufacturer should obtain the hot mix asphalt and materials from states having experienced that type of asphalt pavement problem. 5.1.2. Type BHot mix asphalt and the corresponding
31、 neat asphalt binders recommended by the additive/modifier supplier as particularly appropriate to demonstrate the additives enhancement properties may be chosen, or 5.1.3. Type CSpecific hot mix asphalt and their corresponding neat asphalt binders considered for use in a particular modified asphalt
32、 project or in particular states or regions may be chosen. 6. EVALUATION TESTING Note 1It is suggested that the testing be done by a laboratory inspected for the appropriate tests by the AASHTO Materials Reference Laboratory (AMRL) and enrolled in the appropriate reference sample program by the AMRL
33、. 6.1. Relationship of Modified Asphalt Testing to Tests in Standard AASHTO Asphalt Specification: 6.1.1. A modified asphalt binder, in the first instance, is compared to, and, in general, has to meet the applicable specifications for unmodified asphalt binders. These tests are found in M 320. 6.2.
34、Order of Performing Tests: 6.2.1. The testing order should be based on what the asphalt additive is designed to accomplish. The most crucial tests (“go” or “no-go” tests) should be performed first. For example, if the proposed additive is purported to alleviate stripping as its only benefit, it is m
35、ost appropriate to run Section 6.4.5, Moisture Damage Test, first. Should this test show that the additive provides no anti-stripping properties, there would likely be no reason to run any further tests. If the neat asphalt binder/asphalt binderaggregate mixture responds favorably to this initial te
36、st (or tests), the remaining tests should be performed in order to make sure that the modifier does not have an unfavorable impact on any of the properties of the material. 6.3. Phase I TestingAsphalt Binders: 6.3.1. Pressurized Aging Vessel (PAV)R 28; 6.3.2. Grading or Verifying the Performance Gra
37、de of an Asphalt BinderR 29; 6.3.3. Bending Beam Rheometer (BBR) TestT 313; 6.3.4. Direct Tension Test (DTT)T 314; 6.3.5. Dynamic Shear Rheometer (DSR) TestT 315; 6.3.6. Viscosity Using Rotational ViscometerT 316; 6.3.7. SamplingR 66; 2015 by the American Association of State Highway and Transportat
38、ion Officials.All rights reserved. Duplication is a violation of applicable law.TS-2b R 15-5 AASHTO 6.3.8. SolubilityT 44; 6.3.9. Flash Point by Cleveland Open CupT 48; 6.3.10. Water in Petroleum Products and Bituminous MaterialsASTM D95; 6.3.11. Specific Gravity of Semi-Solid Asphalt MaterialsT 228
39、; 6.3.12. Rolling Thin-Film Oven TestT 240; Note 2The following tests need at least verification and often basic development. Hence, the references given are often indicative rather than definitive. 6.3.13. Limiting Stiffness Method for Predicting Cracking TemperatureFHWA/RD-87/001; 6.3.14. Critical
40、 Stress Method for Predicting TemperatureFHWA/RD-87/001; 6.3.15. Force-DuctilityFHWA/TX85/347/1; 6.3.16. Dynamic Mechanical Analysis (DMA)Including Aging IndexFHWA/RD-87/001; 6.3.17. Time-Temperature Degradation Profile of Additive/ModifierFHWA/RD-87/001; 6.3.18. Aging as Measured by Infrared Spectr
41、oscopy (IR)FHWA/RD-87/001; and 6.3.19. Homogeneity Test (Compatibility Between Modifier and Asphalt)FHWA/RD-87/001. 6.4. Phase II Hot Mix Asphalt: 6.4.1. Short- and Long-Term Aging of Hot Mix Asphalt (HMA)R 30; 6.4.2. Superpave Volumetric Design for Hot Mix Asphalt (HMA)R 35 and M 323; 6.4.3. Hot Mi
42、x Asphalt (HMA) Specimens by Means of the SHRP Gyratory CompactorT 312; 6.4.4. Volumetric Analysis (air voids and voids in the mineral aggregate (VMA): 6.4.4.1. Theoretical Maximum Specific GravityT 209; 6.4.4.2. Bulk Specific GravityT 166 or T 275; 6.4.4.3. Percent Air Voids CalculationT 269; 6.4.4
43、.4. Specific Gravities and Absorption of AggregateT 84, T 85, and T 133; Note 3The bulk specific gravity of the aggregate is needed to calculate VMA. 6.4.5. Moisture Damage TestT 283 or NCHRP-274; Note 4When testing anti-stripping additives, it is recommended that the retained ratio from these tests
44、 for the untreated mixture be less than 70 percent. 6.4.6. Permanent Deformation and Fatigue Cracking Characteristics of Hot Mix Asphalt (HMA) Using the Simple Shear Test (SST) DeviceT 320; and 6.4.7. Resilient Modulus by Indirect Tension (IDT)TP 31.1 2015 by the American Association of State Highwa
45、y and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2b R 15-6 AASHTO 7. REPORT 7.1. Description of asphalt binders; 7.2. Description of aggregates; 7.3. Mix design properties; and 7.4. Results of tests performed. APPENDIX (Nonmandatory Information) X1.
46、 INFORMATION FROM ADDITIVE/MODIFIER SUPPLIER X1.1. What is the material (trade name, generic name, and specific chemical identity)? X1.2. Who is the manufacturer (company name, street address, mailing address, zip code, telephone number, fax number, contact person)? Who supplied it for testing (comp
47、any name, street address, mailing address, zip code, telephone number, fax number, contact person)? X1.3. Physical properties? X1.4. Material Safety Data Sheet (MSDS). Is the material a Resource Conservation and Recovery Act of 1976 (RCRA) hazardous waste? X1.5. What properties does the Additive/Mod
48、ifier improve? X1.5.1. In asphalt binder. X1.5.1.1. What tests demonstrate this? Give details or references. X1.5.2. In hot mix asphalt. X1.5.2.1. What tests demonstrate this? Give details or references. X1.6. Instructions for Use. X1.6.1. Percent. X1.6.2. Method of addition. X1.6.3. Restrictions on
49、 use. X1.7. Qualitative and Quantitative Analysis of Additive/Modifier. X1.7.1. Neat. X1.7.2. In asphalt binder. X1.7.3. In hot mix asphalt. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2b R 15-7 AASHTO X1.8. What asphalt binder, aggregate, and mix design should be used with the additive/modifier? Answer with reference to Section X1.5. X1.9. Marketing Data. X1
