Bituminous Mixtures and Binders
Recent years have seen the introduction of new materials in the production of bituminous mixtures and liquid asphalt binders. Such materials include lime, fly ash, warm mix asphalt additives, rejuvenating agents, recycled asphalt pavement and recycled shingles. A proposed new ASTM International practice for adding these materials to bituminous mixtures and binders is being developed by ASTM International Committee D04 on Road and Paving Materials.
The proposed new standard, ASTM WK38070, Practice for Sample Preparation and Conditioning with Additives, is under the jurisdiction of Subcommittee D04.20 on Mechanical Tests of Bituminous Mixtures.
Richard Steger, director, rehabilitation technologies, InVia Pavement Technologies LLC, and chairman, D04.20, says that many of the new materials are currently being used in the construction of bituminous pavements, but that there are various ways to incorporate the materials in the laboratory. The proposed practice would serve the following purposes:
- Mix designers would be able to use standard methods of incorporation into the design;
- Mixtures produced in the lab would match the performance of materials placed in the field; and
- Performance of the mixtures using these additives would be predictable during the mixture design and liquid asphalt binder formulation stage.
Potential users of the proposed standard, once it is approved, include designers of bituminous mixture and laboratory mixes, asphalt contractors, state highway agencies and companies that develop and supply materials to asphalt contractors who produce bituminous mixtures for state highway agencies.
All interested parties are welcome to join in the standards developing activities of D04.20.
Upcoming Meeting: Dec. 4-6, 2012, December Committee Week, Atlanta, Ga.