Key Technology For Expressway Pavement Widening

At present,the highway construction in our country has gradually entered the stage of full prosperity.Because of the increasing number of private vehicles,the consistent growth of traffic volume and the traffic congestion caused by the increase of traffic flow,many highways built at the early stage have been difficult to adapt to the demand for modern use.Whether it is from the angle of improving the highway conditions,optimizing the quality of service,or improving the overall quality of the highway,the implementation of the expressway pavement widening project is imminent.Based on the current development of pavement widening at home and abroad,this thesis has studied in key technology for expressway pavement widening.Basing on the analysis of the existing asphalt pavement evaluation system in China,an evaluation system adapted to the old pavement widening is established.On this basis,the technical standards and technical schemes for the old pavement widening are discussed and analyzed.Aiming at the prevention measures of asphalt pavement cracks after pavement widening,the physical and mechanical properties of polyester cloth,impervious geotextile,glass fiber grille,polyester glass fiber cloth and anti-crack paste materials,such as material properties,shear strength,pull-out strength,shear strength after freeze-thaw cycle,pull-out strength and fatigue properties,were tested and evaluated.Taking Xibaipo Expressway as a project example and based on the comparative analysis method,three kinds of widening schemes of pavement widening projects are designed,and the finite element analysis models are established respectively by using ABAQUS software.Stress analysis of pavement structure are carried out,resulting in changes that reflected the mechanical response of different overlap widths of pavement.According to the characteristic data and the analysis results of pavement mechanics at different load positions,the best pavement widening scheme is obtained.Basing on the pavement widening scheme,splicing construction scheme and pavement crack prevention measures are put forward.