沥青混合料在重复荷载作用下的黏弹性变形

Viscoelasticity study of asphalt mixture deformation under repeated loading

为了研究沥青混合料在不同温度、不同应力下黏弹性变形响应,提出了基于三轴重复荷载试验评价沥青混合料抗车辙能力的方法,并对沥青路面车辙发展规律进行了分析。采用半正弦波荷载来模拟路面实际车辆荷载,基于黏弹性五单元八参数模型,推导了能够适用于三轴重复荷载试验的力学模型。结合三轴重复荷载试验的试验结果,利用Origin 8.5软件,对三轴重复荷载试验数据进行拟合,得到了相应的黏弹性参数。对比计算流动数和实测流动数,分析沥青混合料黏弹性变形特性。研究结果表明,温度越高、应力越大,混合料黏弹性变形越大,流变性越小;重复荷载作用下沥青混合料永久变形黏弹性力学模型参数拟合相关系数达到95%以上,表明该模型可以有效地反映沥青混合料黏弹性变形特性。

In order to study the viscoelastic deformation response of asphalt mixture under different temperatures and different stresses,a method based on triaxial repeated load test to evaluate the anti-rutting ability of asphalt mixture was proposed,and the development law of asphalt pavement rutting was predicted.The semi-sinusoidal load is used to simulate the actual vehicle load on the road.Based on the viscoelastic five-element eight-parameter model,the mechanical model which can be applied to the triaxial repeated load test is derived.Combined with the test results of the triaxial repeated load test,the original 8.5 software was used to fit the three-axis repeated load test data to obtain the corresponding physical parameters.The flow numbers under different temperature and stress conditions were calculated and compared with the measured flow values.The results show that the higher the temperature and the higher the stress,the larger the permanent deformation of the mixture and the smaller the rheology.Under the repeated load,the correlation coefficient of the parameters of the permanent deformation viscoelastic mechanics model of asphalt mixture is over 95%.The model can effective reflects the permanent deformation characteristics of the asphalt mixture.