冻融腐蚀对沥青混凝土疲劳性能的影响

Effect of Freeze-thaw and Corrosion on Fatigue Property of Asphalt Concrete

通过模拟北方地区季节温差规律，针对3种不同级配的沥青混凝土，在清水和氯化钠饱和溶液中，进行冻融条件下沥青混凝土疲劳性能研究；分析疲劳破坏的作用机理，确定影响沥青路面疲劳性能的主要因素；综合评价级配、盐分腐蚀对疲劳性能的影响，为提高沥青路面的使用年限和耐久性提供理论依据。试验结果表明，在-18～60℃冻融循环作用下，随着冻融次数的增加，沥青混凝土疲劳寿命总体逐渐下降；在相同冻融条件下，3种不同级配的沥青混凝土疲劳寿命大小顺序为：AC-13、AC-16、AC-20；2种不同溶液中的沥青混凝土疲劳寿命，清水中的大于氯化钠饱和溶液中的。

By simulating the seasonal temperature differences in northern China, the fatigue performance of asphalt concrete with 3 gradations under freeze-thaw condition in pure water and saturated sodium chloride solution are investigated. The principle of fatigue damage is analyzed, and the main factors which affect the fatigue performance of asphalt pavement are determined. The effect of gradation and salt corrosion on the fatigue performance is evaluated to provide a theoretical basis for the durability and service life of the asphalt pavement. The test result shows that （ 1 ） the fatigue life of the asphalt concrete gradually decreases as freeze- thaw times increasing under the effect of freeze-thaw cycles from - 18℃ to 60℃ ; （2） when the freeze-thaw condition is same, the fatigue lives of asphalt concrete with 3 gradations decrease in an order of AC - 13, AC- 16, AC-20; （3） the fatigue life of asphalt concrete in pure water is larger than that in saturated sodium chloride solution.