Cracking performance analysis of asphalt mixtures using response surface methodology: experimental investigations and statistical optimization

The study utilized response surface methodology and optimized fracture toughness characteristics that affect the cracking performance of different asphalt mixtures in respect of four parametric variables. The experimental investigation included determination of fracture toughness KIC of nine conventional dense graded asphalt mixes with four replicates per mix type totalling 96 specimens using the static semicircular bending (SCB) test. The statistical response modelling on experimental results showed a good agreement with the predicted data, which certified the appropriateness of the optimization process. Further, the statistical optimization indicated that the measure of fracture resistance of an asphalt mix could be optimized (maximized) at lower test temperatures for thicker specimens prepared with high asphalt content and low air voids. A significant contribution of this study was to devise and use a methodology to optimize the cracking resistance (here, KIC) of asphalt mixes based on a rational test method such as SCB, which could potentially become an algorithm for characterizing any other response parameter in future.