Existing and Evolving Methods of Materials Evaluation for Waste-Modified Asphalt Mixtures Author(s): Terrel, Ronald L.; Lundy, James R. and Hicks, Gary R. Origin: Oregon Date: October, 1993 Categories: Performance Key Words: waste materials, asphalt concrete, SHRP, mixture characteristics, performance, rubber-modified asphalt mixtures Summary: A continued increase in the use of waste materials in highway construction appears inevitable. The incorporation of waste and/or by-products in asphalt concrete mixtures has resulted in many successes and some costly failures. Traditional asphalt mixture design and evaluation test procedures are generally ineffective in identifying which modified mixtures will perform well and which will fail. The shortcomings of traditional methodologies are due to the empirically based design methods and interpretation of results. However, for waste-modified mixture designs and performance predictions will necessarily often fail. Mixture evaluation and testing procedures and performance based criteria, developed as part of the Strategic Highway Research Program (SHRP), may be better suited to distinguish between good and bad performing mixtures. These tests attempt to identify the fundamental material properties of the mixture. Nevertheless, these new procedures have not been fully demonstrated on waste-modified asphalt mixtures. Furthermore, field performance of waste-modified mixtures characterized using SHRP methodology has not been studied. To facilitate the implementation of these evolving procedures, a SHRP-based test methodology that assists in selection of waste-modified mixtures is described.