Study On Performance Decay Of Expressway Asphalt Pavement In Southwest Hebei

On the one hand,the construction and operation of China’s expressways has promoted rapid economic growth.At the same time,it is also facing frequent diseases caused by heavy traffic and complex environments,and road performance has declined year by year.This study relies on the asphalt pavement detection project of the Xing lin Expressway in the southwest of Hebei.Based on the existing research results at home and abroad,the research is basedon the investigation of the physical geography,traffic characteristics,pavement structure and materials in the southwest of Hebei.The mechanical system is used to analyze the mechanical response of typicalpavement structure,and the multiscale interface theory is used to select the indicators that affect the performance of pavement structure under different interface sizes.Specific research work includes:1.Relying on the Xing lin Expressway Inspection Project,it summarizes its physical geographic profile,regional traffic characteristics,pavement structure and materials,and pavement disease characteristics,and analyzes and finds that typical pavement diseases in the area are cracks,ruts,and loose diseases.The most prominent network is crack disease,which is mainly related to road materials and traffic volume,while rut disease is mainly related to heavy traffic.2.Using BISAR 3.0 software to perform a mechanical analysis on the typical structure of the asphalt pavement of the expressway in the southwest of Hebei,it can be seen that the changes in the mechanical response values of the surface layer are more obvious than those of the base layer.The maximum shear stress occurs at the mid-surface layer and is bonded between layers In the incomplete state,the shear stress value is about three times that in the continuous state,and the vertical deformation of the upper layer surface increases sharply after exceeding 80% of the standard axial load.;3.Selecting asphalt pavement structural performance evaluation indexes at different scales for experiments and detection analysis,it is found that the effect of early temperature on each index is far greater than the influence of humidity,and the resistance to deformation of graded asphalt mixtures has a greater impact.The deformation ability is the smallest,and the medium-grain type and the coarse-grain type are almost the same;in the environment exceeding 60 ℃ and 0.9 MPa,the rutting deformation speed of the asphalt mixture increases sharply,and the total deformation amount is more than double.4.The grey correlation analysis was used to analyze the correlation of each index to obtain the correlation between each sub-index and the rut depth index: rut deformation> pavement structure strength> asphalt film thickness> aggregate angularity,and regression analysis obtained Jixi Southwest Expressway asphalt The road decay model is (?)...