Evaluation of Anti-cracking Performance of Modified HMA in Stress Absorbing Layers Under Low Temperature

In order to evaluate the low temperature anti-cracking performance of mixture with compound modified asphalt at stress absorbing layers,test fixture and specimens were designed,test parameters were determined and disk-shaped tension experiment was carried out,and then the low temperature anti-cracking performance was evaluated by tensile stiffness,tensile failure strength and fracture energy.Furthermore,the influence of aggregate gradation,test temperature,asphalt binder and asphalt aggregate ratio on low temperature anti-cracking performance was analyzed.The results indicate that the fracture energy is the comprehensive index to evaluate low temperature anti-cracking performance,aggregate gradation sensitively affects anti-cracking performance,the mixture with gradation close to median limit is not the best and the rational test temperature to evaluate low temperature anti-cracking performance is 0 ℃;the low performance of common SBS modified asphalt can not meet the demand of stress absorbing layers under low temperature.