Numerical Investigation Of The Interlayer Durability Between Long-Life Micro Overlay And Asphalt Pavement Surface

Pavement preventive maintenance technology has developed rapidly,meanwhile,the preventive maintenance technology of asphalt pavement all over the world has born rich fruits in prolonging the service life of the highway and reducing the overhaul input.However,there are still such deficiencies as no obvious effect in prolonging the service life of pavement with the application of numerous kinds of preventive maintenance technology,so the Long-live Micro Overlay with enough interlayer bonding durability to solve such problems encountered in the existing preventive maintenance technology.In this paper,an interlayer numerical analysis model is established to analyze the stress of the layer and interlayer and the interlayer damage law as well,after the implementation of Long-life Micro Overlay under different loading conditions.Compared with the traditional interlayer continuous model,it is rational to apply the recommended interlayer model;the recommended interlayer model is used to predict the interlayer shear fatigue life of Long-life Micro Overlay to the existing asphalt pavement and thin asphalt overlay.The main contents are as follows:(1)Comparative analysis of different interlayer model and methods to study the interlayer bonding durability is made to select the cohesion model which is suitable for asphalt concrete interface,and then the progressive damage theory of delamination failure model is introduced;the model described above is applied as the simulation of laboratory direct shear test,verifying the model according to the existing literature.(2)The finite element software ABAQUS is applied to establish the interlayer model(surface-based cohesive behavior)using the delamination failure theory,simulating the interlayer bonding condition after the implementation of the LLMO.The model described above is applied under standard axle loading,analyzing the stress of the layer and interlayer and the interlayer damage law as well.Meanwhile,compared with the traditional interlayer continuous model,it is rational to apply the recommended interlayer model.This model is used to analyze the stress of the layer and interlayer and the interlayer damage law as well under different loading conditions.(3)In order to analyze the interlayer shear fatigue behavior and the loss of interlayer stress,the interlayer model using the delamination failure theory is established under repeated load of medium traffic.The results show that there is no delamination failure during the loading period,which is consistent with the actual life of the LLMO.In addition,the thin asphalt overlay-the existing pavement interlayer model is established,predicting the interlayer shear fatigue life of 3.6 years,which is much lower than the service life of the LLMO.(4)With reference to the relevant allowable shear strength calculation formula given by the specification of urban road,the expression of the interlayer shear fatigue life of pavement-overlay.The interlayer shear fatigue life of LLMO and thin asphalt overlay is obtained under repeated loading conditions.