Asphalt Mixture Behavior in Repeated Flexure: Fid-Bau Portal

Asphalt Mixture Behavior in Repeated Flexure

C. L. Monismith

The first phase of the study was concerned with defining the influence of asphalts from different sources and hardness and aggregate type on the fatigue characteristics of asphalt concrete using controlled-strain tests. The second continuing phase explores the application of laboratory fatigue data to predict the performance of in-service pavements. Controlled-stress fatigue tests were made on specimens sawed from the pavement courses and on laboratory-prepared specimens of the same components. Triaxial compression repeated load tests were made on recompacted granular and subgrade materials. Test procedures for controlled-strain, controlled-stress fatigue tests and repeated load triaxial tests are given. The report gives a comprehensive discussion of fatigue testing and approximate guides to assist in the selection of mode of loading depending on the pavement section under study. Stiffness of the mixture was used to assist in the interpretations of the fatigue data. The application of fatigue characteristics to the design of asphalt concrete pavements is discussed. A suggested procedure is presented in terms of stress in the asphalt concrete. Simplifying assumptions were made for temperature (influence on stiffness), lateral displacement of wheel loading and aging affects of asphalt aging. (Author)