Research On Structural Performance Of Highway Graded Gravel Base Asphalt Pavement

Most highway in our country are asphalt pavement structure of semi-rigid base, which kindof pavement structure easily lead to various diseases. The application of graded gravel baseasphalt pavement could effectively improve the structural performance, with good prospects fordevelopment and application.Firstly the paper conducts mechanical analysis for graded gravel base asphalt pavement.Make sensitivity analysis of pavement structure parameters using orthogonal methods, deeplyanalyzing the main influence factors and discussing the change rule of each index, to providereference for the graded gravel base asphalt pavement structure design. It creates thethree-dimensional finite element model of graded gravel base asphalt pavement with cracks byANSYS software, to research the law of open fracture stress intensity factor along with eachstructural layer parameters under symmetrical loads. It draws conclusions that graded gravel basecan effectively inhibit the reflective crack of semi-rigid base. Then study on the design methodsof graded gravel base asphalt pavement, to determine the four design indexes which control thedamage of graded gravel base asphalt pavement, that are the bottom flexural tensile strain ofsurface layer, the top vertical compressive strain of soil base, the bottom flexural tensile stress ofsemi-rigid base and the top vertical shear stress of graded gravel base. Based on the traffic levels,it recommends typical asphalt pavement structure of graded gravel base for reference in practicalapplication.Further the paper conduct theoretical research applied to Zhangshi highway test road, todetect pavement performance through embedding pressure box and strain foil, verify thereliability of theoretical analysis and the practicality and feasibility of mentioned typicalstructure to achieve mutual unity of theory and practice, and provide the theoretical support andtechnical reference for the nationwide promotion of graded gravel base asphalt pavement. Finallyit makes use of total life cycle cost method for economic benefit analysis, although the initialcost of graded gravel base asphalt pavement is high, the total life cycle cost of graded gravelbase asphalt pavement is less than semi-rigid base asphalt pavement. The longer economicanalysis period is, the more obvious economy advantages of the graded gravel base has. In viewof this, the highway asphalt pavement of graded gravel base has good economic and socialbenefits.