沥青混合料抗裂性能评价指标的试验研究

Research on Evaluating Index of Anti-cracking Performance of Asphalt Mixture

基于沥青路面裂纹扩展行为,设计预切口小梁试件的疲劳试验,以模拟其复合裂纹扩展模式;以疲劳寿命指标来评价沥青混合料的抗裂性能,同时进行沥青混合料的低温弯曲试验和J积分试验,试验混合料采用4种低温性能差异显著的沥青胶结料.判别各项评价指标对试验混合料抗裂性能的鉴别程度,并分析沥青低温临界温度指标、低温弯曲试验指标、J积分试验指标与预切口小梁疲劳寿命的相关性.结果表明:以混合料疲劳性能为基准的混合料抗裂性能排序与沥青胶结料临界温度的排序一致,也与沥青混合料低温弯曲试验和J积分试验中能量指标的排序一致.

Based on the crack growing behavior of asphalt pavement, the fatigue test of asphalt mixture notched beam was designed to simulate the mixed mode fracture, and the fatigue life was taken as an index for anti-cracking performance of asphalt mixture. 4 kinds of asphalt binder with significantly different low temperature performance were selected, conventional low temperature bending test and fracture mechanics J-integral test were performed. By determining the identified levels of these indexes on testing mixtures, correlations between the low temperature critical temperature of asphalt, the index of low temperature bending test, the index of J-integral test and the fatigue life of notched beam were examined. It is sugges- ted that the orders of anti-cracking performance based on fatigue property of asphalt mixture are consistent with the order of asphalt critical temperature, and it is also consistent with the energy indexes of low temperature bending test and J-integral test.