NCHRP 09-43 [Completed]
Mix Design Practices for Warm Mix Asphalt
| Project Data
||Advanced Asphalt Technologies, LLC|
||Dr. Ramon Bonaquist|
||The project final report is available as NCHRP Reports 691 and 714.|
The objective of this project was to develop a mix design method for warm mix asphalt (WMA) in the form of a draft AASHTO-recommended practice for use by engineers and technicians in the public and private sectors. This method was to (1) be based on Superpave mix design methodology, (2) include a suite of performance tests to assess whether a WMA mix design will provide satisfactory field service, and (3) be applicable to any WMA technology used to lower mixing and compaction temperatures..
The key product of this research project is a draft recommended appendix to AASHTO R 35, Standard Practice for Superpave Volumetric Design for Hot-Mix Asphalt (HMA), titled Special Mixture Design Considerations and Methods for Warm Mix Asphalt (WMA). This recommended appendix was developed and validated by the results of an extensive program of laboratory and field testing on a wide range of WMA technologies. In addition to this practice, the contractor produced (1) a chapter on WMA mix design for inclusion in the mix design manual produced in NCHRP Project 9-33, A Mix Design Manual for Hot Mix Asphalt, and (2) materials and media for a 1-day training course on WMA mix design.
The project final report is available as NCHRP Report 691, Mix Design Practices for Warm Mix Asphalt. The print and PDF versions of the report include three appendixes:
Appendix A: Draft Appendix to AASHTO R 35: Special Mixture Design Considerations and Methods for Warm Mix Asphalt (WMA);
Appendix B: Commentary to the Draft Appendix to AASHTO R 35; and
Appendix D: Proposed Standard Practice for Measuring Properties of Warm Mix Asphalt (WMA) for Performance Analysis Using the Mechanistic-Empirical Pavement Design Guide Software.
The remaining two appendixes are only available online:
Appendix C: Training Materials for the Draft Appendix to AASHTO R 35; and
Appendix E: NCHRP Project 09-43 Experimental Plans, Results, and Analyses.
A supplement to NCHRP Report 673, A Manual for Design of Hot Mix Asphalt with Commentary, based on Appendix A of NCHRP Report 691 is available as NCHRP Report 714, Special Mixture Design Considerations and Methods for Warm Mix Asphalt: A Supplement to NCHRP Report 673: A Manual for Design of Hot Mix Asphalt with Commentary.
Information on a core set of WMA specimen conditioning procedures and test methods proposed for common use, insofar as possible, in all present and future WMA studies are presented in NCHRP Research Results Digest 370, Guidelines For Project Selection And Materials Sampling, Conditioning, And Testing In Wma Research Studies.