AC-13沥青混合料损伤比强度理论及车辙现象预测OA北大核心

The high-grade pavement structure predominantly adopts asphalt pavement,which experiences a complex triaxial stress state under the influence of traffic loads and environmental temperature.This often leads to the occurrence of rutting.So far,there is no strength theory available to explain the phenomenon of rutting.To tackle this challenge,the damage ratio strength theory was applied within the strain decomposition assumption for the unit and the extreme value computational model of relative energy consumption rate to predict the multiaxial strength and rutting phenomenon of AC-13 asphalt mixtures.Based on the strength characteristics of the failure envelopes for asphalt mixtures under triaxial compressive conditions,and with reference to the value of damage ratio parameter for lightweight aggregate concrete under tension,five coefficients in the damage ratio variable were proposed based on multiaxial test data of asphalt mixtures,forming the damage ratio strength theory for asphalt mixtures.Results are drawn.The dimensionless triaxial strength of AC-13 asphalt mixtures remains consistent across different temperatures.The predicted results of the strength theory align well with the multiaxial strength test results of AC-13 asphalt mixtures at different temperatures.Subsequently,based on the damage ratio strength theory for asphalt mixtures,simplified forms of the confining triaxial criterion and biaxial criterion are proposed,along with recommended values for empirical coefficients.The proposed simplified criteria can reasonably predict the confining triaxial and biaxial strength values of AC-13 asphalt mixture at different temperatures.The results show that the confinement coefficient of the asphalt mixture is 2.6,which falls between lightweight aggregate concrete and plain concrete,and the ratio of biaxial isobaric strength to uniaxial compressive strength is 1.38.The damage ratio strength theory reveals that under heavy vehicle loads,asphalt pavement undergoes a triaxial isostatic stress state,resulting in zero octahedral shear stress values and exhibiting plastic flow,thereby leading to the occurrence of rutting on the pavement.