ABSTRACT
To investigate the factors affecting the crack resistance of ultra-thin overlay, the crack characteristics of asphalt mixes were analyzed, and crack correlation parameters of asphalt mixtures were constructed. Three grades of EMC10, AC10, and CPA10 and SBS modified asphalt, as well as high-elasticity modified asphalt were selected to test the volume index of mixtures, and the crack resistance of mixtures was tested by bending test and crack extension test; finally, the influence of crack correlation parameters and crack resistance was analyzed. The research results show that: cracks develop along the edge of the aggregate in asphalt mixtures, and the cracks mainly occur in the asphalt mortar; the low-temperature bending strain of the dense gradation is greater than that of the open gradation mixture; OT test shows that the fracture energy of continuous gradation is greater than that of discontinuous gradation; the content of mortar and the ratio of powder to rubber has a significant correlation to the three crack performance indexes εB , Gc , and Gs . Increasing the content of asphalt mortar can improve the crack performance, and viscosity has a significant impact on the crack resistance of the mixtures.
