动态贯入下浇注式沥青混合料的永久变形研究

Research on permanent deformation of gussasphalt mixture under dynamic penetration

基于修正Burgers模型推导出动态贯入下浇注式沥青混合料永久变形的模型,用该模型对浇注式沥青混合料（GA-10）在动态贯入试验下的永久变形试验数据进行了回归分析,获得了不同温度、荷载应力峰值和间歇时间下的模型参数.试验结果表明：高温重载是使浇注式沥青混合料产生永久变形的重要因素,永久变形经历了快速增长和缓慢增长两个阶段;高温使黏弹性变形恢复的能力下降,黏弹性残余应变量增大,同时加速永久变形量的产生;由于混合料硬化松弛的影响,间歇时间越长,混合料产生的永久变形量越大,在不同间歇时间下,黏度和非线性增长速度值基本保持不变;较大的荷载应力峰值使混合料的内应力变大,黏弹性变形恢复能力变强,但重载会加速永久变形量的增长.

A mechanical model based on the modified Burgers model under dynamic penetration test was deduced.To obtain the model parameters on different temperature,peak value of the load stress,and intermittent time,the permanent deformation of gussasphalt mixture（GA-10） in dynamic penetration test were regressed by the model.Experiment results show that high temperature and overloading are the pivotal factors leading to great permanent deformation,and the permanent deformation of gussasphalt mixture experiences two stages：rapid growth and slow growth.The higher temperature weakens the recovery ability of viscoelastic deformation and speeds up the production of permanent deformation.Due to the influence of hardening-relaxation of mixture,the longer intermittent time,the greater amounts the permanent deformation of the mixture accumulates.Besides,the parameter viscosity and nonlinear growth rate are basically unchanged at different intermittent times;the higher loading causes the internal stress in the mixture become larger,and enhances its viscoelastic deformation recovery ability,despite the acceleration of the growth of the permanent deformation due to the overloading.