PHYSICAL PROPERTIES OF ASPHALT CEMENT AND THE DEVELOPMENT OF PERFORMANCE-RELATED SPECIFICATIONS

One of the primary objectives of the Strategic Highway Research Program (SHRP) is to develop performance-related specifications for asphalt cement. This paper describes the program of research that is being pursued by the authors to develop new or improved test methods and specification criteria that are suitable for the development of a performance-related specification for asphalt cement. This paper consists of six sections, each of which is relevant to the problem of developing more effective specifications for paving grade asphalts: (1) a review of asphalt rheology; (2) a brief discussion of the chemistry and microstructure of asphalt cement; (3) a review of the traditional methods of characterization; (4) a discussion of the shortcomings of current specifications; (5) a description of proposed test methods and specification framework; and (6) a final section in which the information presented in this paper is summarized, and a few important conclusions are made concerning the development of performance-related specifications for asphalt cement.