Structural Analysis And Research On Fissure Mechanism And Maintenance Technology Of Portland Cement Concrete Pavements

The Cement concrete pavement, as one of the high-grade pavement structures, has been widely used because of such advantages as high strength, good stability, great durability, high temperature stability, abrasive hardness and for cost of maintenance. In line with the theories of the present pavement designs, the cement concrete pavement, with normal performance in the structure of every layer, deal Inter-layer contact as well as good designs and construction, will usually not break until a long time of use or the time designed. But actually, quite a number of such pavements show defects or crackles of varying degrees within 2-5 years or shorter. In recent years, the effect of sharp traffic volume, heavy axis load and overload truck speeds up the damages of the concrete pavement. These damages lead to the destructive of pavement structure and reduce of load carring capacity or lower surface function so that these seriously influence the driving comfort and safety .For this reason. Meanwhile, owing to its features such as high cost far maintenance, severe traffic interference during maintenance, and difficulty in maintenance of what is damaged.So it is a problem for serving immediate solution in present-day projects, to improve the ability of analyzing PCC, to understand fully the influence of heavy load on PCC, to know the fissure mechanism and breaking process of the cement concrete and improve its anti-fissure, and to enhance the maintenance technology. The paper has done some research work about these problems. The main contents of the paper are as follows:1. The analysis was done on PCC using FEM. It defined the thickness of slab, the elastic modulus of base, the elastic modulus of soil and the load of vehicle as the variants. The effect on the stress and displacement concluded, this provided a reference to design PCC.2. It has also analyzed the influence of overloading to pavement structure by mechanical means and put forward a lot of countermeasures.3. The stress status of fissure ends was analyzed with the theory of Fracture Mechanics, and the process of breaking open was analyzed by the mechanics of pavement. In addition, the effects of vehicles, temperature and water on its fatigue life are analyzed.4. The systemic researches were done about the maintenance, fissure servicing, and the renovating and constructing technologies of old PCC were introduced with the practical projects.