Application Study On Rehabbing Old Cement Concrete Pavement With Asphalt Overlay

The construction of cement concrete pavements in our country begins at the middle of 60's. At present, a majority of cement concrete pavements constructed in early days have been close to or exceeded its age-limit, mostly appearing damage to some extent. It is necessary to maintain or reconstruct the old cement concrete road. The reconstruction of old cement concrete pavement with a asphalt overlay has the advantages of short work period, little influence on transportation, little investment and comfortable drive etc, which is a kind of simple and valid rehabilitation measure at home and abroad. The Shiyan section of No.316 national highway (K1549+850~ K1582+120) is the main road from Xiangfan to Shiyan in Hubei province, which also is the important passage from Shiyan to the central region. Its design grade is a second class highway of heavy area of mountain or hill. Through the running of the big traffic volume for many years, most cement concrete pavements already appear large-scale damage in the year of 2002, it is exigent to reconstruct the old cement concrete pavements greatly. Currently, there is not much mature experience concerning the repair techniques of old cement concrete pavement that can be provided as reference. The article regard the old cement concrete pavement in Dingjiaying town (K1571+600~ K1573+800) of the Shiyan section of No.316 national highway as experimentation, closely keep contact with the practice of reconstruction engineering, through investigation and evaluation of road situation, the project design, the theories analysis, the system analysis and study of construction craft, forms a complete set of techniques of adding the asphalt overlay on old cement concrete pavement. It is the successful key of adding the asphalt overlay on old cement concrete pavement to control the creation and development of reflecting crack. The article discussed all kinds of treatment measures relevant to damage of old cement concrete pavement on the base of investigation and evaluation detailed in order to improve the bearing capacity of old panel. The article discusses various design methods of asphalt overlay structure according to the characteristics of research pavement's situation, put forward various treatment measures and construction craft that can defer the creation and develop of reflecting crack, which include the application of new materials of geotextile and glass fiber geogrid etc. The article analyzes the stress state of asphalt overlay in load stress at the critical load position by a calculation of finite element procedure ANSYS, verifies the rationality of design project on research pavement's overlay, still analyzes the parameters of each structure layer on composite pavement at the same time, which all can provide some beneficial experience and references for project design of maintenance and reconstruction on the old cement concrete pavement later on.