Viscoelastic Behavior of Asphalt Concrete in Diametral Compression

Abstract

A viscoelastic solution of the diametral compression of short cylinders has recently been presented by Zhang et al. The solution is based on Hondros's elastic solution and applies to any load history. In this paper, the viscoelastic solution is used for analyzing the haversine load history. Expressions are derived for the real and imaginary parts of the complex compliance, as functions of phase angles and amplitudes measured in tests, and algorithms are presented for their evaluation. The theoretical solution is illustrated with a series of tests on two asphalt concrete mixtures, subjected at room temperature to haversine loading over a wide range of frequencies. It is shown that power-law creep compliance satisfactorily describes the deviatoric viscoelastic behavior of the tested materials. The volumetric behavior, on the other hand, is nearly frequency-independent and can be approximated by a purely elastic law. The results of this paper demonstrate that incorporating viscoelasticity in the interpretation of the diametral compression test is viable and provides valuable information on asphalt concrete viscosity-related properties.