沥青混合料永久变形黏弹性力学模型通用性研究

Research on Viscoelastic Mechanical Universal Model of Permanent Deformation of Asphalt Mixture

为了拓展沥青混合料永久变形黏弹性力学模型的适用宽度,满足不同温度区间和应力水平的要求,实现在全温域条件下沥青混合料永久变形预估,对6种典型沥青混合料进行了三轴重复荷载蠕变试验,研究不同温度和不同应力水平下的永久变形规律;构建了考虑行车荷载存在间隙期的重复荷载作用下沥青混合料黏弹性力学模型;建立了温度、偏应力与重复荷载作用下沥青混合料黏弹性力学模型参数关系方程并进行了修正。研究结果表明:沥青混合料在低温、中温、高温不同阶段表现出不同的永久变形特性,从全温域角度考虑沥青混合料永久变形发展规律更加符合实际状况;温度、轴载大小和荷载作用次数对沥青混合料的永久变形均有着较大的影响,且三者存在着等效关系;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及参数与温度、偏应力的关系方程拟合的效果良好,均大于90%以上,提高了沥青混合料永久变形黏弹性力学模型的通用性。同时,确定了不同温度的平均修正系数,使永久应变计算结果更加准确。

In order to expand suitable width of the viscoelastic mechanical model of permanent deformation of asphalt mixture,to meet different temperature intervals and horizontal forces,to achieve permanent deformation prediction of asphalt mixture under the condition of the whole temperature field,triaxial repeated load creep tests are employed to study at different temperatures and different stress levels of permanent deformation law of six kinds of typical asphalt mixture in this paper;Viscoelastic mechanical model of asphalt mixture is constructed considering the effect of repeated load gap period under traffic load;The equation was established among the temperature,partial stress and the parameters of viscoelastic material mechanics model of asphalt mixture under repeated loading and corrected.The results show that asphalt mixture material shows different permanent deformation characteristics in different stages of low temperature,medium temperature,high temperature,and it is more in line with the actual situation from the point of view of the whole temperature field considering asphalt mixture permanent deformation development;Temperature,load size and the number of cyclic loading on permanent deformation of asphalt mixture have great influence,and equivalent relation exist among the three;viscoelastic mechanical model parameter fitting of asphalt mixture under repeated load,the parameter and temperature and equation of partial stress relation are all excellent in fitting,with the temperature and the partial stress being greater than 90%,Universality of viscoelastic mechanical model of permanent deformation of asphalt mixture is improved.At the same time,the average correction coefficient of different temperatures is determined,which makes the calculation results more accurate.