Shear accumulated equilibrium compliance as permanent deforamtion susceptibility parameter

Abstract

Described procedure summarizes the derivation of accumulated creep compliance in the sequence of the creep and recovery cycles that can be easily fitted to experimentally measured data. The local minima in each measured cycle after the recovery were selected and combined into a set that characterized the irreversible deformation of the specimen during the test. Further, the interval fitting procedure was utilized. The estimation of the discrete retardation spectrum from the used 4-modes standard Kelvin-Voigt model was discussed and the accumulated compliance calculated. It was proved that the accumulated compliance may be used as the pavement rutting criterion (expressing the performance of asphalt in terms of its susceptibility to permanent deformations). The proposed theory was demonstrated on experimentally measured asphalt properties in the two test devices. Repeated Shear tests were performed in the Superpave Shear Tester and the Uniaxial Shear Tester. It was found that the accumulated equilibrium compliance correlates with the asphalt mix rutting parameters. As it is presented and in the view of the general principles showing that long-time processes are revealed in more detail in the retardation spectrum, the use of the accumulated equilibrium compliance can be useful as a criterion for the long life rutting potential.