Analysis of Nonlinear Behavior of Asphalt Concrete During Marshall Test

The Marshall method is one of the most common techniques used in the design of asphalt concrete mixes. However, the structural behavior of the asphalt concrete specimen during the Marshall test is not clearly understood. In this study the stress distribution and displacements that occur in the specimens at different loading stages in a Marshall test are evaluated, based on results of unconfined compression test and a nonlinear plane-stress finite element analysis. Analytical predictions show that large stress concentration occurs near the points of separation between the Marshall specimen and the loading heads, and that values of the displacements are close to those observed experimentally. Extension of this study may lead to the development of relations between Marshall stability and flow values and the asphalt mixture strength parameters based on principles of mechanics that are necessary in the structural modeling of the pavement.