Study On Structure Of Asphalt Pavement With Function Layer

Presently in the expressway pavement structure in our country, semi-rigid asphalt pavement is widely spread and applied for its high integral strength, good Physical properties of board and low cost. However, with the rapid development of the expressway construction and the increasing traffic volume, the traditional semi-rigid asphalt pavement gradually exposure a series of early damage, such as reflection crack, water damage, rutting, which seriously affect the service performance and life of the asphalt pavement.Aiming at the early damage of the semi-rigid asphalt pavement, our country's road workers researched and found that they were structure damage. So optimization of semi-rigid asphalt pavement structure is the key to solve the early damage of the semi-rigid asphalt pavement.Firstly, based on the long-li-long expressway in Zhejiang province, this paper put forward a new structure form that asphalt treated permeable base or binding course is set between surface course and semi-rigid base, to improve the drainage function of the asphalt pavement and reduce the craking degree and rutting depth through investigation and analysis of the semi-rigid asphalt pavement damage in Zhejiang province, reference of the foreign successful experience, and discussion of the feasibility of various strctures.Secondly, this paper determines the setting condition and method of asphalt treated permeable base and binding course, and validates its rationality though calculating and analysing the mechanical response of the pavement structure.At the same time, based on the theory of elastic fracture mechanics, this paper also estimate the fatigue life of the semi-rigid asphalt pavement and the pavement with function layer, which shows that the latter has a better fatigue life and can restrain the crake in semi-rigid base spreading to the surface course. Based on these, this paper studies the anti-fatigue of the asphalt pavement with function layer, and then determines the parameter range of each structure layers, which is proved by laboratory test., which is testified by laboratory related test.Lastly, this paper makes the structure design of the rutting resistance of the pavement with function layer, and then contrasts and analyses with the semi-rigid pavement structure, with the conclusion that the pavement structure with function layer has the better rutting resistance.