The Mechanics Response Analysis On Asphalt Pavement Structure With Flexible Base

Along with the long-term research and application of our country's highways, some inherent defect of the semi-rigid base asphalt pavement gradually revealed, it mainly displays as follows:greatly shrinkage of semi-rigid base material, poorly water stability, poorly drainage performance, which lead pavement to early damage, such as tracking, crazing and potholes and so on. It seriously influence the service function of the road, as well as influence service life and service level of the semi-rigid base asphalt pavement directly. In order to solve the serious demolishment of the semi-rigid base asphalt pavement, more and more research commit themselves to find a new pavement structure form, asphalt pavement with flexible base gradually come into our sight.Asphalt pavement with flexible base is usually includes a combination of materials (basic) asphalt pavement, stabilized macadam asphalt pavement (lie aggregates layer or directly on the improvement of subgrade soil). Among them, asphalt stabilized macadam materials show great advantage in high shear strength, flexural strength and fatigue resistance. Compared with the semi-rigid base material, asphalt stabilized macadam materials performance better in shrinkage cracking and water damage. As the stress of asphalt stabilized macadam dissipate layer, which can effectively reduce the stress concentration of the asphalt pavement structure and greatly retard reflection crack of the surface. At the same time, the surface material and the basic material of asphalt macadam similar to each other, grass-roots bonding between the two kinds of material is more substance, also the modulus of stress and deformation of the pavement structure is more harmonious. In European countries, the pavement structure form is extensively applicated in highway and heavy traffic expressway, and achieved good results, but the research has just started in domestic.In this paper, combined with the characteristics of asphalt pavement with flexible base, the damage forms and mechanism of asphalt pavement structure is studied firstly, and the fem elastic theory is introduced after that. According to China's current asphalt pavement design method, by applying the software ANSYS, built the physical model of pavement structure, the elasticity of the bonding layer between the earth and the constitutive model for simulation analysis, the results show that the design theory ,which assumes that layer between the earth is completely continuous and the assumes material for line elastic, has great effect on stress response of the asphalt treatment base (ATB) flexible pavement, which lead the design tends to unsafe condition.In order to further understand the asphalt treatment base flexible pavement, this paper analyses the response characteristics of four different types of pavement structure mechanics and comparative analysis of asphalt pavement with flexible base, and draw the conclusion that comprehensive performance is better than the other three pavement structure. Then the papers researched the recommended pavement structure of the HePing-ZuoLing trial pavement section, and get the pavement structureâ…¡-1. Finally analysis the parameter sensitivity, scheme and parameter optimization for asphalt pavement with flexible base, provide reference to designers.