Crack Propagation Characterization of Asphalt Mixtures: Weibull Distribution and Entropy Approach

Abstract

The semicircular bending (SCB) test is used to characterize crack propagation of asphalt mixtures at intermediate temperatures using the critical strain energy release rate or the flexibility index, known as the Louisiana method and the Illinois method, respectively. Both methods neglect the effect of dissipated energy during testing, which may cause variability in materials characterization. This study used the probability density function of Weibull distribution to develop a relationship between the load-line displacement and the corresponding load for the SCB test at various temperatures. Two mathematical models are presented to compute two parameters, the initial bending stiffness and the normalized Shannon entropy, which is a new approach to parameterize the specimen’s mechanical response during loading. These two parameters are used to characterize crack propagation resistance of asphalt mixtures; at the same initial bending stiffness value, higher normalized Shannon entropy values may indicate better resistance to crack propagation. On the other hand, at the same Shannon entropy value, higher initial bending stiffness values may indicate the ability to carry heavier loads.