The Research For Calculation And Experiment Of Internal Force About Asphalt Pavemen And Steel Bridge Deck

At present, the focal point of our country road construction put on to newly build and reconstruct highway, seriously deficiency on the existence road maintenance and the cognition and devotion of technological transformation. According to prediction, the peak maintained and reconstruction in cement concrete pavement has not come yet, in several years, this question will be shown especially out gradually.The repair of the cement concrete pavement is very difficult, there are two kinds of measures mainly both at home and abroad: the first one is adding asphalt concrete layer, the second one is adding cement concrete layer. As the asphalt overlay can effectively improve old cement concrete pavement, enhance the comfortableness when the vehicle goes, and construction is convenient, influence to traffic and environment is small, so it mostly used in the reconstruction project of old cement concrete road at home and abroad, but the fatal weakness is at the joint or crack of cement concrete pavement ,the asphalt overlay produces cause reflective crack. It ? cause the service life shortened .It is still a great technological problem in the road engineering circle, how to control the production and development of the reflective crack.This thesis start with the destructive mechanism of asphalt overlay, form angle of fracture mechanics analyze reflective crack expand mode of asphalt overlay: the shearing type of reflective crack and opening type of reflective crack. Then analyze the cause of formation and expansion mechanism of reflective crack. From the viewpoint of fracture mechanics, think the reflective crack of asphalt overlay inside reason is primitive defect in old crack or seam of concrete pavement, which cause the asphalt overlay stress centralization and inside damage. The reflective crack go through three stages: the stage of crack arises, expand stage, break stage.In allusion to how to prevent and slow down reflective crack of asphalt overlay, This thesis use grade macadam method, use common software ANSYS of finite element, analyze asphalt overlay in vehicle loads, temperature, loads, and the vehicle loads and temperature loads and acts on the coupling stress together. Through different operating modes, such as the loading capacity of the axle, the elastic mould of asphalt overlay, the thickness of asphalt overlay, the mould of the ground , the thickness and the mould of grade macadam, and extent of lower the temperature ,etc, obtaining a large number of calculation data, it open out stress centralization in asphalt overlay form the angle of mechanics and it testified that grade macadam can alleviate crack.Develop the binding material which resist high shearing strength, low and high temperature is the key to solve the disease of asphalt overlay. As to sticking layer of the new materials, while guaranteeing intensity, mere should be good resisting fatigue life .Through testing it in order to grasp its fatigue life under different stresses level. Understand it destroys state and performance.