黏弹性对沥青路面疲劳开裂的影响

Effect of viscoelasticity on fatigue cracking of asphalt pavement

建立了黏弹性三维有限元模型,对典型沥青路面结构路表及沥青层底的水平应力进行了计算,分析了荷载模式及温度对黏弹性响应的影响。结果表明:在循环荷载作用下,路表和沥青层底都经受水平压应力和拉应力的重复作用,且在路表和沥青层底分别产生少量的残余拉应力和残余压应力,这有可能是造成沥青路面从上到下或从下到上疲劳开裂的原因之一。随着温度的升高,残余应力减少,且路表产生的压应力幅值和沥青层底产生的拉应力幅值都降低。

A viscoelastic 3-D finite element model was built to calculate the horizontal stresses in the surface and bottom layers of typical road asphalt pavement structure,and the effects of loading mode and temperature on their viscoelastic responses were analyzed.The results showed that the surface layer and the bottom layer of the road pavement experience the repeated horizontal tensile and compressive stresses under cyclic loading and small residual tensile and compressive stresses build up in the surface layer and bottom layer respectively.This is probably one of the factors causing top-down or bottom-up fatigue cracking in the asphalt pavement.The residual stresses,the compressive stress amplitude in the surface layer and the tensile stress complitude in the bottom layer of the asphalt pavement of the road all decline with rise of temperature.