An alternative method for computing thermal stress in asphalt mixture: the Laplace transformation

Low-temperature cracking is one of the most severe distresses for asphalt pavement experiencing severely cold weather conditions. Many road authorities recognise thermal stress as a crucial parameter for evaluating the low-temperature performance of asphalt pavement. Thermal stress is conventionally computed with a two-step approach where the relaxation modulus is derived from the experimental creep compliance after which the convolution integral is numerically solved. In this paper, a one-step computation solution based on Laplace transformation is proposed. Thermal stress and corresponding critical cracking temperature of a set of six mixtures are easily computed and graphically and statistically compared to the values obtained with the traditional approach. It is observed that the use of the Laplace-based method provides reliable and reasonably close results to those obtained with the conventional solution.