Research On Cement Concrete Pavement Rebuilding Technology On City Road Intersection

Cement concrete pavement in China built-in the eighties and nineties close to or exceed the design life,China’s road construction into the large-scale transformation of the curing period. Asphalt overlay on its driving comfort, short construction period, and easy maintenance advantages to become the main form of cement concrete pavement, rutting and reflective cracking problem in the form of this transformation has also become the main research object of the current road workers, but study aimed specifically at the intersection of the special position of the overlay is still less.This paper investigated the S120intersections traffic and road conditions, evaluation of road damage, and takes the appropriate measures to deal with the original road surface disease. According to the climate characteristic of DongGuan and the stress characteristic of the intersection, after reading lots of literature at home and abroad on the basis of engineering examples, select AC20-C, AC13-C and SMA-13three kinds of gradation type,tentatively set the asphalt overlay on the program, and mechanical analysis. According to the analysis results, choose AH-70asphalt which modified by SBS, select RK300, the EP, styrene-butadiene as well as fiber and other asphalt concrete additives on asphalt mixture.experimental study on the performance of asphalt by conventional grading types, the modification effect of the additives as well as better content, and dynamic compressive strength values to evaluate high temperature deformation resistance of asphalt mixture,thus put forward to apply to the intermediate layer,upper layer asphalt mixture design of the cement concrete pavement reconstruction project of the DongGuan S120intersection. The course of the study reached the following main conclusions:(1)The maximum shear stress of the overlay structure is between the overlay and cement concrete pavement, and therefore should take measures to combat reflective cracking between the overlay and the original road, called for the strengthening of the shear resistance of the surface material.(2)Increase the thickness of the overlay material and improve the modulus can effectively reduce the tensile stress and shear stress in the overlay, but also improve the rut resistance of asphalt pavement.(3)The construction temperature of modified asphalt determined by the viscosity-temperature curve is high, temperature compaction method can be used to determine the temperature of the construction of modified asphalt. (4)Incorporation of anti-rutting agent can significantly improve the high temperature stability of the asphalt mixture, it is recommended that the dosage of anti-rutting agent control in less than0.3%, the content within this range does not affect the co-ordination of the mixture design. Mixed with styrene-butadiene materials can reduce the temperature sensitivity of the asphalt and improve its resistance to deformation at elevated temperatures and crack resistance at low temperatures.(5)Dynamic stability may not fully reflect the high temperature stability of the asphalt mixture, can use the dynamic compressive strength characterization of high temperature deformation resistance of asphalt mixture.Finally, the study identified in the middle layer, the upper layer asphalt mixture design composition paving test road in DongGuan city S120intersection, the construction quality of the test section was detected and analyzed, the results show two overlay programs can efficiently improve the intersection of rutting resistance.