CONICET | Buscador de Institutos y Recursos Humanos

The Marshall test and rutting test are the usual experimental techniques for the characterization and design of recycled asphalt mixture, as well as in the case of conventional mixtures. These tests evaluate the stability and the strain limit of the mixture, which are determinant properties in conventional mixtures design, but not in the recycled mixtures, where the stiffness grows due to the ageing of the old added material. However, this can influence in other mechanical properties of the recycled mix, which are not clearly described by these usual tests, like cracking strength or tenacity. These new specific properties demands new methods of testing to know the really conditioning mechanical variables taking part in the process, so that being able to characterize and design new recycled mixes in an optimum way. Due to this fact, a new test is presented ? Direct Tensile Test ? to characterize and evaluate the properties of recycled asphalt mixtures. This test is applied to the characterization of recycled asphalt mixes with different percentages of Reclaimed Asphalt Pavement (RAP). This new experimental method is supported, among several test comparison, by numerical simulation, able to reproduce the material?s behaviour with a fairly good approximation. A constitutive formulation has been developed based in the viscoplastic model including the strain rate variable in the constitutive parameters. This model is presented and applied to simulate the experimental results obtained. This numerical method is useful to support the analysis of the recycled asphalt properties depending on the RAP content, the temperature, to reach an accurate characterization of the material. The direct tensile test is a very simple method which provides more information about the tenacity and cracking strength, and so is a useful test for the characterization of recycled asphalt mixes.

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