Material Characteristics of Asphalt Rubber Mixtures

Material Characteristics of Asphalt Rubber Mixtures

Authors: Kamil E. Kaloush, Aleksander Zborowski, Andres Sotil, George B. Way



This study focused on conducting a laboratory experimental program for several Asphalt Rubber (AR) mixtures to obtain their typical engineering properties and understand their good field performance. Most of the laboratory program was based on test recommended by the National Cooperative Highway Research Program, NCHRP 9-19 Project, which dealt with recommending Simple Performance Tests (SPT) for the evaluation of asphalt mixes. These tests included: consistency binder tests, triaxial shear strength, repeated load permanent deformation, dynamic modulus, flexural beam fatigue, and indirect tensile tests. The results obtained for the AR mixtures were also compared, when possible, with results obtained for conventional mixtures.
The AR mixes were those typically used in the State of Arizona, USA, along with an experimental mixture that was constructed by Alberta Transportation, Canada. All laboratory test specimens were prepared using mixes that were collected during construction. The tests also included sensitivity studies of the mixtures to air voids, temperatures, and influence of confinement level.
It was concluded that many parameters obtained from the above tests were successful in describing the observed field performance of AR mixes.

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