1、Standard Practice for Evaluation of Asphalt Additives and Modifiers AASHTO Designation: R 15-18Technical Section: 2b, Liquid Asphalt Release: Group 3 (August) American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 20001 TS-2b R 15
2、-1 AASHTO Standard Practice for Evaluation of Asphalt Additives and Modifiers AASHTO Designation: R 15-18 Technical Section: 2b, Liquid Asphalt Release: Group 3 (August) 1. SCOPE 1.1. This standard practice covers the laboratory testing required to evaluate asphalt additives and modifiers in both as
3、phalt binders and mixtures. The terms “additive” and “modifier” are used interchangeably and are broadly interpreted to include any materials added to asphalt binder in minor amounts, other than mineral fillers, sand, and aggregates, whose purported effect is to change the effective performance grad
4、e of the asphalt binder, or to otherwise improve the performance and service life of pavements or maintenance materials by improving the properties of the asphalt binder or asphalt mixture, or both. This standard does not include modifications due to the use of recycled materials. 1.2. Following is
5、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-StrippingMoisture susce
6、ptibility of the asphaltaggregate bond. 1.2.4. Warm Mix Asphalt (WMA) Technologies/Compaction Aids. 1.2.5. Extenders/Softeners. 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 Asph
7、alt Binder M 332 Performance-Graded Asphalt Binder Using Multiple Stress Creep Recovery (MSCR) Test R 28, 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 2018 by the
8、 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 44, Solubility of Bituminous Materials T 48, Flash and Fire Points by Cleveland Open Cup T 228, Specific Gravity of Semi-Solid Asphalt Material
9、s T 240, Effect of Heat and Air on a Moving Film of Asphalt Binder (Rolling Thin-Film Oven Test) T 313, 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, Determi
10、ning the Rheological Properties of Asphalt Binder Using a Dynamic Shear Rheometer (DSR) T 350, Multiple Stress Creep Recovery (MSCR) Test of Asphalt Binder Using a Dynamic Shear Rheometer (DSR) PP 78, Design Considerations When Using Reclaimed Asphalt Shingles (RAS) in Asphalt Mixtures TP 92, Determ
11、ining the Cracking Temperature of Asphalt Binder Using the Asphalt Binder Cracking Device (ABCD) TP 101, Estimating Fatigue Resistance of Asphalt Binders Using the Linear Amplitude Sweep TP 113, Determination of Asphalt Binder Resistance to Ductile Fracture Using Double-Edge Notch Tension (DENT) Tes
12、t TP 122, Determination of Performance Grade of Physically Aged Asphalt Binder Using Extended Bending Beam Rheometer (BBR) Method. 2.1.2. Aggregates: T 37, Sieve Analysis of Mineral Filler for Hot Mix Asphalt (HMA) T 84, Specific Gravity and Absorption of Fine Aggregate T 85, Specific Gravity and Ab
13、sorption of Coarse Aggregate T 133, Density of Hydraulic Cement 2.1.3. Mixtures: M 323, Superpave Volumetric Mix Design R 30, Mixture Conditioning of Hot Mix Asphalt (HMA) R 35, Superpave Volumetric Design for Asphalt Mixtures R 83, Preparation of Cylindrical Performance Test Specimens Using the Sup
14、erpave Gyratory Compactor R 84, Developing Dynamic Modulus Master Curves for Asphalt Mixtures Using the Asphalt Mixture Performance Tester (AMPT) T 166, Bulk Specific Gravity (Gmb) of Compacted Asphalt Mixtures Using Saturated Surface-Dry Specimens T 209, Theoretical Maximum Specific Gravity (Gmm) a
15、nd 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 Asphalt Mixtures Using Paraffin-Coated Specimens T 283, Resistance of Compacted Asphalt Mixtures to Moisture-Induced Damage T 312, Preparing and D
16、etermining the Density of Asphalt Mixture Specimens by Means of the Superpave Gyratory Compactor T 321, Determining the Fatigue Life of Compacted Asphalt Mixtures Subjected to Repeated Flexural Bending T 324, Hamburg Wheel-Track Testing of Compacted Asphalt Mixtures 2018 by the American Association
17、of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-2b R 15-3 AASHTO T 331, Bulk Specific Gravity (Gmb) and Density of Compacted Asphalt Mixtures Using the Automatic Vacuum Sealing Method. T 340, Determining Rutting Susceptibility of Ho
18、t Mix Asphalt (HMA) Using the Asphalt Pavement Analyzer (APA) T 342, Determining Dynamic Modulus of Hot Mix Asphalt (HMA) T 378, Determining the Dynamic Modulus and Flow Number for Asphalt Mixtures Using the Asphalt Mix Performance Tester (AMPT) TP 105, Determining the Fracture Energy of Asphalt Mix
19、tures Using the Semicircular Bend Geometry (SCB) TP 107, Determining the Damage Characteristic Curve of Asphalt Mixtures from Direct Tension Cyclic Fatigue Tests TP 108, Abrasion Loss of Asphalt Mixture Specimens TP 124, Determining the Fracture Potential of Asphalt Mixtures Using the Semicircular B
20、end Geometry (SCB) at Intermediate Temperature 2.2. ASTM Standard: D95, Standard Test Method for Water in Petroleum Products and Bituminous Materials by Distillation 3. SUMMARY OF METHOD 3.1. The testing is divided into two phases. Phase I tests the modified binder (with tests of appropriate unmodif
21、ied controls), while Phase II tests the modified asphalt mixture. The purpose of dividing the testing into two phases is 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.
22、This would not apply if the additive/modifier interacts specifically with the aggregate, e.g., in the case of 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
23、 is compared, as is appropriate, either with the same asphalt binder unmodified or with asphalt binder from the 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 proc
24、edures are those desirable for an unmodified asphalt binder. Both modified asphalt binder and asphalt mixture 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
25、 control asphalt binders are used and tested specifically for those properties to be enhanced by the modifier. 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
26、performance properties of the modified asphalt binder are either unsatisfactory or significantly degraded, and 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, smal
27、l-scale field trials and economic cost-benefit analysis may be warranted. If the additive/modifier is being promoted 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 provi
28、ded in Appendix X1. 2018 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 5. CHOICE OF CONTROL SAMPLES 5.1. Control samples may be chosen for three purposes. Type A control samples are use
29、d for the most general evaluation of additive/modifiers. Type B is used when the supplier believes that the additive/modifier is useful under 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 aspha
30、lt mixtures and their corresponding unmodified asphalt binders, which are commonly used as paving materials, must be chosen. 5.1.1. Type AAsphalt mixtures and their corresponding unmodified asphalt binders spanning the range of those typically used throughout the United States may be chosen. It is r
31、ecommended that the additive manufacturer obtain representative asphalt mixture designs and constituent materials currently being produced for and approved by three state highway administrations. Depending on the purpose of the additive, the manufacturer should obtain the asphalt mixture and materia
32、ls from states having experienced that type of asphalt pavement problem. 5.1.2. Type BAsphalt mixtures and the corresponding unmodified asphalt binders recommended by the additive/modifier supplier as particularly appropriate to demonstrate the additives enhancement properties may be chosen, or 5.1.
33、3. Type CSpecific asphalt mixtures and their corresponding unmodified asphalt binders considered for use in a particular modified asphalt 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 accredited for the
34、appropriate tests by the AASHTO Accreditation Program and enrolled in the AASHTO re:source Proficiency Sample Program. 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 gen
35、eral, has to meet the applicable specifications for unmodified asphalt binders. These tests are found in either M 320 or M 332. 6.2. 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” tes
36、ts) should be performed first. For example, if the proposed additive is purported to alleviate stripping as its only benefit, it is most 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
37、 no reason to run any further tests. If the unmodified asphalt binder/asphalt binderaggregate mixture responds favorably to this initial test (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 th
38、e material. It should also be noted that not all the tests listed are necessary, and the agency should determine which test it needs to perform. 6.3. Phase I TestingAsphalt Binders: 6.3.1. SamplingR 66; 6.3.2. Rolling Thin Film OvenT 240; 6.3.3. Pressurized Aging Vessel (PAV)R 28; 2018 by the Americ
39、an Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-2b R 15-5 AASHTO 6.3.4. 6.3.5. 6.3.6. 6.3.7. 6.3.8. 6.3.9. 6.3.10. 6.3.11. 6.3.12. 6.3.13. 6.3.14. 6.3.15. 6.3.16. 6.3.17. 6.4. 6.4.1. 6.4.2. 6.4.3. 6.4.4. 6.4.4.1. 6.4.
40、4.2. 6.4.4.3. 6.4.4.4. 6.4.5. 6.4.6. Grading or Verifying the Performance Grade of an Asphalt BinderR 29; Bending Beam Rheometer (BBR) TestT 313; Direct Tension Test (DTT)T 314; Dynamic Shear Rheometer (DSR) TestT 315; Multiple Stress Creep RecoveryT 350; SolubilityT 44; Flash Point by Cleveland Ope
41、n CupT 48; Water in Petroleum Products and Bituminous MaterialsASTM D95; Specific Gravity of Semi-Solid Asphalt MaterialsT 228; Resistance to Ductile FailureTP 113; Extended Bending Beam RheometerTP 122; Critical Low Temperature (Tc); Determining the Cracking Temperature of Asphalt Binder Using the
42、Asphalt Binder Cracking Device (ABCD)TP 92; Estimating Fatigue Resistance of Asphalt Binders Using the Linear Amplitude SweepTP 101. Phase II Asphalt Mixture: Short- and Long-Term Aging of Hot Mix Asphalt (HMA)R 30; Superpave Volumetric Design for Hot Mix Asphalt (HMA)R 35 and M 323; Preparing and D
43、etermining Density of Asphalt Mixture (HMA) Specimens by Means of the Superpave Gyratory CompactorT 312. Volumetric Analysis (air voids and voids in the mineral aggregate (VMA): Theoretical Maximum Specific GravityT 209; Bulk Specific GravityT 166, T 275, or T 331; Percent Air Voids CalculationT 269
44、; Specific Gravity and Absorption of AggregateT 84, T 85, and T 133; Note 2The bulk specific gravity of the aggregate is needed to calculate VMA. Moisture SusceptibilityT 283 and T 324; Note 3When testing anti-stripping additives, it is recommended that the tensile strength ratio from T 283 for the
45、untreated mixture be less than 0.70 percent. RuttingT 324, T 340, and T 378, Procedure B. 2018 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-2b R 15-6 AASHTO Note 4It is recommended that the test temper
46、ature, failure rut depth, number of passes at maximum impression, and stripping inflection point criteria should be determined based on local or regional specifications. 6.4.7. Permanent Deformation: 6.4.7.1. Preparation of Cylindrical Performance Test Specimens Using the Superpave Gyratory Compacto
47、r (SGC)R 83; 6.4.7.2. Dynamic Modulus and Flow NumberT 378; 6.4.7.3. Dynamic Modulus Master Curves for Asphalt Mixtures Using the Asphalt Mixture Performance Tester (AMPT)R 84. 6.4.8. Fatigue Cracking Characteristics: 6.4.8.1. Determining the Fatigue Life of Compacted Asphalt Mixtures Subjected to R
48、epeated Flexural BendingT 321; 6.4.8.2. Fracture Potential Using Semicircular Bend GeometryTP 105 or TP 124; 6.4.8.3. Determining the Damage Characteristic Curve of Asphalt Mixtures from Direct Tension Cyclic Fatigue TestsTP 107; 6.4.9. Abrasion Loss of Asphalt Mixture SpecimensTP 108. 7. REPORT 7.1
49、. Description of asphalt binders; 7.2. Description of aggregates; 7.3. Mix design properties; and 7.4. Results of tests performed. 8. KEYWORDS 8.1. Asphalt additives; asphalt binder; asphalt mixture; asphalt modifiers. APPENDIX (Nonmandatory Information) X1. INFORMATION FROM ADDITIVE/MODIFIER SUPPLIER X1.1. What is the material (trade name, generic name, formulary designation, and specific chemical identity)? X1.2. Who is the manufacturer (company name
