Disease Analysis And Numerical Study Of Two Stage Highway Of Paving Cement Concrete Pavement

The old cement concrete pavement began to appear in a variety of structuraldisease due to traffic surge, overloading of vehicles and the highway service life. Theold cement concrete function is difficult to meet the increasing traffic demand, andalso will cause traffic safety problems. To restore the road function, we’re pavingasphalt overlay or cement concrete overlay in the old cement concrete pavemen. Theresearch and construction of the asphalt overlay on old cement concrete pavement ismore, and the study of cement concrete overlay is relatively less. Therefore designand construction of the cement concrete overlay on the old cement concrete pavementis slightly inadequate, resulting in pavement early diseases, affecting the normal useof the highway operation.When the rebuilding of Hunan G322highway pavement(Santang town, HengnanCounty-Baidishi town, Qidong County),we build on the concrete overlay on oldcement concrete pavement, and use two pieces of plate width (5.5m+5.5m) and threepieces of board width (4m+3m+4m) in pavement construction, in the highwayoperation overlay of two pieces of concrete slab have longitudinal cracks in the edgeof the road2.0-2.5m,in the three frame concrete overlay, length of5m concrete plateswas rare diseases, only local length of10m concrete plates have transverse cracking.Analysis results showed that, temperature stress of two pieces of overlay is large andthe subgrade uneven deformation adaptability is poor, might be the main cause oflongitudinal crack; only local length of10m concrete plates have transverse crackingin the three frame concrete overlay mainly is the concrete slab length is too long,produced by the comprehensive effect of temperature and vehicle load by theABAQUS. Therefore, the length of5m three plates overlay form is feasible.In this paper, according to three plates overlay form, we were set paving schemeB(4m+3m+4m), paving scheme C (3.5m+4m+3.5m), paving scheme D (3m+5m+3m),analysis shows that, the longitudinal seam should not be placed near the vehicle wheel trace; concrete slab width is about4m, the wide concrete plates should be placed inthe middle, narrow concrete plate is arranged into the pavement outside, can reducevehicle load and temperature stress, and improve the fatigue life of concrete pavementby the finite element. Performance of paving scheme C is better, therefore, pavingscheme C is recommended. Through the plate thickness analysis, if the base andsubgrade shoulder were reinforced, overlay thickness may wish to choose25cm underthe standard axle load, taking into account the overloading of vehicles, Overlaythickness should be set to28cm.