Evaluating Crack Resistance of Asphalt Mixture Based on Essential Fracture Energy and Fracture Toughness

Two kinds of asphalt binders and four kinds of aggregate gradations were selected. Cylinder specimens of six types of asphalt mixtures were molded by the superpave gyratory compactor (SGC) rotary compaction method, and semicircular bending (SCB) tests were conducted with different temperatures and notch depths. The effects of notch depth, gradation, asphalt properties, and temperature on the crack resistance of the asphalt mixture were analyzed based on essential fracture energy and fracture toughness. The analysis results show that the greater the notch depth leads to lower fracture energy and weaker crack resistance. The effect of gradation is slight when the nominal maximum particle size is relatively large, and smaller nominal maximum particle size leads to greater effect of gradation on crack resistance of the asphalt mixture. Asphalt properties have a positive influence, which means higher quality bitumen would give higher crack resistance. The effects of gradation and asphalt properties on crack resistance are limited by temperature.