Refining the Calculation Method for Fatigue Failure Criterion of Asphalt Binder from Linear Amplitude Sweep Test

Abstract

The objective of this paper is to refine the calculation method for improving the regression accuracy of fatigue failure criterion of asphalt binder using the linear amplitude sweep (LAS) test, especially for the highly modified asphalt binders. The maximum stored pseudo strain energy (Max WsR)-based failure criterion was studied for interpreting the LAS test data under multiple-loading rates to predict the fatigue life of asphalt binders. However, the regression accuracy of the Max WRs-based failure criterion for neat asphalt binders is generally better than that of modified binders. In this paper, a parameter of total released pseudo strain energy (TRPSE), which measures the area under the pseudo strain energy (PSE) curve until fatigue failure occurs, was developed as a material characteristic parameter, which demonstrates that no matter what loading rates are conducted during the LAS tests, the TRPSE value is constant at a specific temperature for a given asphalt binder. The proposed TRPSE value was obtained from the averaged results of the six replicates under three LAS loading rates; then the failure criterion was recalculated, and the regression accuracy significantly improved for the studied neat and modified binders. Applying this improved TRPSE-based failure criterion for the prediction of fatigue life presented more reasonable results, especially for the modified binders studied at multiple temperatures and strain amplitudes.