The Practical Study Of Asphalt Overlay And Stress Absorb Layers On Cement Concrete Pavement

In recent years, quite a few of existing cement concrete pavements of our country have already been close to or exceeded anticipated service life. Some pavements don't reach anticipated service life, but they have been damaged in various degree or their use quality has dropped because the volume of traffic increases severely, automobile axle weighing becomes heavy - duty day by day or other reasons, such as design and construction. The damage of some cement concrete pavements is very serious. That has great influenced the comfortableness of driving, made the speed difficult improved and the traffic capacity dropped.So it has very important theoretical and realistic significance for studying repaving and renewal of existing cement concrete pavements of expressway that the overall and careful evaluation and analysis to existing cement concrete pavements are carried on and the research of technology for repaving and renewal of existing pavements is made on such basis.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 1st circle road of Chengdu 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.While existing cement concrete pavements damaged seriously is repaired or reconstructed, involved questions as following. First, the state of existing cement concrete pavements is evaluated, including carrying capacity, voids, the state of joints and pavement surface of such function performance, structure performance and so on. Second, the renewal of existing pavements should satisfy the need of technology, as well as it should be economical.Third, they should make the repaving pavement satisfy the need of anti - skid, evenness and compactness, and it must have enough anticipated service life that the selection of the existing pavement repaving project and design are. Fourth, the study, of technological measure for interlayer management between the old pavement and the new pavement and preventing reflection crack.The material of stress absorb layers has the superiority in delaying or restraining the reflection cracks of the old concrete road surface, and this is different from general intermediate layer of prevent fracturing .So it becomes one kind of important technological schemes which is adopted in adding asphalt on the concrete road surface of old cement.