Analysis On Rehabilitation Of Old Portland Cement Concrete Pavement

The cement concrete pavement and the asphalt pavement are two main types of highway pavements in our country. By the end of 2005, there are 532,697-kilometer highways with paved surface, of which 57.56% or 306,622-kilometer roadways are Portland cement concrete pavements. It should be pointed out that a number of the country's Portland cement concrete pavements have been used for a long time and distressed by the overloaded transportation as a result of intensively competitive transportation markets. All those cement concrete pavements are in urgent condition waiting for maintenance and/or rehabilitation. As requested by the community to enhance environmental protection, the recycling of old concrete pavements has become one of the important contents. For deeply research on the pavement structrure and the recycling material, it would promote the advancement of maintaining theory of the concrete pavements. From the widespread application prospect, it will significantly benefit the economy of the society.Acorrding to the damage degree of old cement concrete pavement, at present, there are three rehabilitation measures commonly used. First, put up new cement concrete surface;Second, put up asphalt concrete overlay;Third, rebuild cement concrete pavement.The detailed presentation of a cement concrete road surface damage survey and assessment methods to determine the maintenance approach increases access to the shop floor design first-hand information;The present paper selects the three-dimensional calculational program ANSYS calculate the max stretch stress at the bottom of the slab, It's helpful to use the finite element method to design the cement concrete pavement;The present paper analysis the theory producing a reflection cracks of the old concrete surface layer of asphalt, the prevention and control measures;The present paper use the wasted cementconcrete in Chengdu to produce RCA(Recycled Concrete Aggregate), analysis the physical and mechanical feature of RCA, then make the RAC. By analyzing each component of the RAC through many experiments, the results of the test is satisfied. The RAC made by RCA reaches our predicted objective and has a series of high performance: easy mix, high early strength, high compressive strength, high bending strength, good ageing resistance etc. This shows that the old cement concrete pavement renewable materials have broad prospects for development.