Effect of Modification on Fracture Failure and Thermal-Volumetric Properties of Asphalt Binders

During the last two decades, several research efforts have focused on the thermal cracking behavior of asphalt binders. Recently, important low-temperature cracking models have been introduced to include the failure properties and thermovolumetric properties at low temperatures. The main objective of this study is to evaluate selected modified asphalt binders in terms of low-temperature failure and related thermovolumetric properties. The effect of modification on fracture failure properties and related thermovolumetric properties of asphalt binder was determined by laboratory testing. The low-temperature cracking temperatures using the collected laboratory testing data were predicted. The focus of this study is on how commonly used asphalt modifiers affect the failure and thermovolumetric properties for a wide temperature range, in particular at low temperatures. Efforts were also made in this study to put more emphasis on the consideration of strain criterion, the effect of cooling rate, and nonlinearity of the coefficient of thermal contraction of asphalt binders into the prediction of low temperature cracking. The results indicate that modification of asphalt binders can have significant effects on their properties and predicted thermal cracking temperatures. The findings also suggest that in order to have a better understanding of binder behavior, the use of both failure and thermovolumetric properties is necessary.