沥青路面反算模量与沥青混合料动态模量的关系

Relationship between back-calculated modulus of asphalt pavement and dynamic modulus of asphalt mixture

为获取沥青路面结构层沥青材料模量参数,合理评价沥青路面结构性能,开展沥青路面反算模量与同温度下室内沥青混合料动态模量的关系研究。采用落锤式弯沉仪(FWD)对4个不同结构的沥青路面试验路进行测试,并通过路面结构埋设的温度传感器同步采集温度,对试验结果进行沥青层模量反算;采用沥青混合料性能试验机(AMPT)对试验路沥青材料进行动态模量试验,根据时温等效原理获取FWD测试的同温度下的沥青混合料模量值,结合沥青路面结构层厚度计算沥青混合料动态模量的当量模量;对沥青层同一温度下的FWD反算模量与动态模量的当量模量进行分析比较,建立回归模型。结果表明,不同路面结构的FWD反算模量与室内动态模量的关系基本一致,其变化趋势不依赖于沥青层厚度的变化;沥青路面FWD的反算模量和室内AMPT的模量呈非线性关系,当模量较小时,FWD反算模量要低于室内模量,随着模量的增加,在10000MPa附近时,二者的模量值是接近的,模量值再继续增大时,FWD反算模量的增加较快,明显大于室内动态模量,室内动态模量的增长趋于平缓。

In order to obtain the modulus parameters of asphalt material in asphalt pavement structure and evaluate the structural performance of asphalt pavement reasonably,the study on the relationship between back-calculated modulus of asphalt pavement and the dynamic modulus of indoor asphalt mixture at the same temperature was conducted.Falling weight deflectometer(FWD)was used to test four asphalt pavement test roads with different structures,and the temperature sensors embedded in the pavement structure were used to collect the temperature synchronously.The modulus of asphalt layer was back calculated by test results.Asphalt mixture performance tester(AMPT)were applied to testing the dynamic modulus of asphalt material in test road,and the modulus values of asphalt mixture in FWD test at the same temperature were obtained according to the time-temperature equivalence principle.In consideration of the thickness of asphalt pavement structural layer,the equivalent modulus of dynamic modulus of asphalt mixture was calculated.FWD back-calculated modulus and the equivalent modulus of dynamic modulus of asphalt layer at the same temperature are analyzed and compared,and a regression model was established.The results show that the relationships between FWD back-calculated modulus of different pavement structures and indoor dynamic modulus are basically identical,the variation trend of the relationships is independent of the thickness of the asphalt layer.FWD back-calculated modulus of asphalt pavement has nonlinear relation with the modulus of asphalt mixture of indoor AMPT.When the modulus values are low,the back-calculated modulus of FWD is lower than that of indoor modulus.With the increase of modulus,the two modulus values are close around 10000MPa.With further increase of modulus,the back-calculated modulus of FWD increases faster than the indoor modulus,while the increase of indoor dynamic modulus tends to be mild.