基于MMLS3的半刚性基层沥青路面材料冻融试验研究

Research on Freezing and Thawing Test of Semi-rigid Base Asphalt Pavement Based on MMLS3

基于MMLS3加速加载设备,综合考虑了湿度、温度、荷载耦合作用,提出了荷载-冻融试验系统,既克服足尺寸试验周期长、消耗大的不足,又避免传统室内试验方法的尺寸效应。主要介绍了小尺寸加速加载试验设计方案,并根据缩尺路面结构,制定了光纤光栅传感器测试方案,分别在结构面层顶、上基层中部、下基层中部埋设了传感器,用于测试加速加载过程中的应力应变场和温湿度场,研究路面在有无冻融条件下的损伤演化规律。试验结果表明,冻融作用下的路面结构试件在加速加载过程中损伤劣化速度明显快于无冻融的路面结构试件,小尺寸加速加载试验方法可以用作路面结构冻融损伤程度评价。

In this paper, based on the MMLS3 accelerated loading equipment, the coupling effect of humidity, temperature and load are considered, and the load-freezing and thawing test system is put forward, which not only overcomes the shortness of long cycle and great consumption of the full size test, but also avoids the size effect of the traditional indoor test method. In this paper, the design scheme of small-scale accelerated loading test is introduced, and the test plan of fiber grating sensor is established according to the road structure of reduced scale. The sensor is embedded in the upper layer of structural surface, in the middle part of upper base and the middle part of upper base, respectively, which are used to test the stress-strain field and the temperature-humidity field in the accelerated loading process, and to study the damage evolution of pavement with or without the condition of freeze-thaw. The experimental results show that the damage and deterioration speed of the pavement structure specimen in the accelerated loading process is significantly faster than the pavement structure specimen without the condition of freeze- thaw. The small-scale accelerated loading test method can be used to evaluate the damage degree of pavement structures.