Development of a New Performance Indicator to Evaluate Resistance of Asphalt Mixes to Cracking

Abstract

Several monotonic performance indicators that use one or more elements of the load–displacement curve (e.g., area under the curve, curve peak) are used to assess the resistance of asphalt mix to cracking. While these indicators have their own merits, they lack the full description of the load–displacement curve. This study developed a new performance indicator called the Weibull cracking resistance index (WeibullCRI), which describes the entire load–displacement curve. The study performed an extensive laboratory evaluation of 16 different asphalt mixes tested in two different testing protocols [i.e., indirect tension (IDT) test and semicircular bending (SCB) test] to evaluate the proposed indicator. The findings of this study demonstrated that WeibullCRI results are sensitive to the variation in binder content and binder performance grade (PG) and were in good agreement with expected cracking resistance based on the composition of the studied mixes. In addition, WeibullCRI had low variability and provided a good statistical grouping of mix resistance to cracking. The study recommended IDT to determine WeibullCRI in order to assess asphalt mix resistance to cracking.