Research On Function Division Theory And Method Of Asphalt Pavement

Early damage for high-grade asphalt pavement under heavy traffic in our country is serious; whereas, long-life asphalt pavement with more than 40 years'service life has appeared in some foreign countries. One highlight of long-life asphalt pavement is to conduct asphalt pavement function division, which determines the function and selects material in each layer according to mechanical response. In view of the above situation, this paper studied the theory and method of asphalt pavement function division, aiming to provide instructions to pavement design, pavement material selection so as to extend the service life of asphalt pavement in our country.In the perspective of mechanics, the failure pattern of asphalt pavement can mainly be divided into three categories:top-down cracks, fatigue cracks and rut. Based on these failure patterns, the paper discussed the mechanical response of the pavement in details:firstly, by means of a finite element software-ANSYS,3D finite element models of full-depth pavement, flexible pavement and combined pavement were established; then, along the depth of pavement, this paper calculated and analyzed the variation rules of horizontal strain along the carriageway, first principal strain and shear stress respectively, and concluded the influences of asphalt layer thickness H1 and elastic modulus E1 on the mechanical response of the pavement; finally, the paper put forward some measures to reduce pavement damage.Based on the research on mechanical response, and combined with the experience in the practical use of asphalt pavement, the asphalt pavement layer was divided into five functional areas:â… -pavement surface protective layer,â…¡-instability type rut sensitive area,â…¢top-down crack sensitive area,â…£-fatigue crack sensitive area,â…¤-function sensitive area, which is a valuable guidance to pavement design and material selection.