Professor of Civil Engineering and research engineer, The Institute of Transportation Studies, University of California, Berkeley, Berkeley, CA
Senior vice president, ARE, Inc., Scotts Valley, CA
Consulting civil engineer, B. A. Vallerga, Inc., Oakland, CA
Pages: 33 Published: Jan 1989
The design of an asphalt concrete mix consists, essentially, of the following steps: 1. select type and gradation of aggregate, 2. select type and grade of asphalt, with and without modifier, and 3. select proportionate amount of asphalt in asphalt/aggregate blend.
These steps have been incorporated into a general framework for design, which serves as the basis for the mix design procedure presented in this paper.
Essentially, the system consists of a series of subsystems in which the mix components and their relative proportions are selected in a step-by-step procedure to produce a mix that can then be tested and evaluated to ensure that it will perform adequately in the specific pavement section for which it has been formulated. The latter evaluation phase includes the influence of environmental factors, effects of traffic, and the consequence of the anticipated structural cross-section design at the designated site in the following distress modes: fatigue, rutting, thermal cracking, and raveling.
The paper includes a brief discussion of the important factors associated with the various steps of the design process and recommended test procedures to be followed. Information and data are presented to illustrate a procedure that might be followed to ensure that the laboratory method of specimen preparation and fabrication provides specimens with stress versus strain characteristics similar to those obtained by field compaction. The use of the creep test to assist in the design process is illustrated. Some techniques to reduce the amount of testing associated with the methodology described herein are also described.
asphalt concrete mix design, fatigue, rutting, thermal cracking, raveling, fracture characteristics, water sensitivity, kneading compaction, creep testing, mix design, asphalt concrete, asphalt specifications
Paper ID: STP20068S