Evaluation of low-temperature fracture and damage of asphalt concrete using SCB test combined with DIC

Abstract

This study presents a method for assessing low-temperature damage and cracking in asphalt concrete by monitoring the surface displacement of semicircular bending (SCB) specimens during loading using digital image correlation (DIC) technology. The inflection point on the load line displacement (LLD)-crack tip opening displacement (CTOD) curve is used to identify the damage initiation, while the macroscopic crack morphology is employed to determine the critical fracture point. Based on the crack opening displacement measured along the crack propagation zone, damage evolution is quantified combining the linear softening cohesive zone model (CZM). Local and global damage factors are introduced to characterize the damage process. The results indicate that damage of asphalt concrete initiates before the peak load, occurring at approximately 90 % of the peak load at −10 °C. The horizontal displacement along vertical characteristic lines above the notch effectively evaluates the crack propagation behavior, providing a reliable approach for damage quantification in asphalt concrete.