沥青混合料低温抗裂性能及影响因素评价

摘要

In order to evaluate the low-temperature crack resistance performance of asphalt mixtures, 3 kinds of bitumen and 3 kinds of gradation were chosen to form nine kinds of asphalt mixture, and low-temperature linear contraction coefficient test and low-temperature bending test were conducted to evaluate contraction crack resistance performance and bending crack resistance performance of asphalt mixtures respectively. Two-factor analysis of variance were used to analyze the test results and the results show that bitumen and gradation have no significant effects on low-temperature linear contraction coefficient, and that low temperature contraction crack is mainly affected by in-situ temperature. The results also show that bitumen and gradation have significant effects on low temperature flexural tensile strain. The bending crack resistance performances of different asphalt mixtures sort from weak to strong: 70-A bitumen, 90-A bitumen, SBS modified bitumen, and SMA-13, AC-16, AC-13.%为了评价沥青混合料的低温抗裂性能,选择3种沥青和3种级配,两两组合形成9种沥青混合料,采用低温线收缩系数试验和低温弯曲试验分别评价其抗收缩开裂能力和抗弯拉开裂能力.对试验结果进行双因素方差分析,结果显示,沥青和级配对低温线收缩系数均没有显著影响,温缩裂缝主要受外界温度等因素影响;沥青和级配对低温弯拉应变有显著影响,不同沥青和级配组成混合料的抗弯拉开裂能力由弱至强分别依次为:70-A基质沥青、90-A基质沥青、SBS改性沥青和SMA-13、AC-16、AC-13.