The Research Of Pavement Structure Of The Old Cement Concrete Pavement With Asphalt Concrete Overlay On It

Paving asphalt pavement on the old concrete pavement can effectively improve the old cement concrete pavement performance. It has the advantages of convenient construction,short construction period,the impact on traffic of the environmental is small and asphalt surface is easy maintenance and upkeep. It has become a common measure to improve the performance of cement concrete pavement and extend the service life of pavement. However,during the use of overlay,it easily emerges the reflect cracking in asphalt concrete pavement Under the traffic load and temperature load . Because of the original crack in cement concrete,and this brings severe negative influences on the life of pavement.Today there has no mature design of overlay though having had research and test on this aspect in our country.It is necessary to study the performance of pavement structure on the asphalt overlaid on the old cement concrete pavement.This paper is relay on the renovation and pavement reconstruction on old cement concrete pavement of Gaojie freeway.Through on-site investigation to obtain the damaged condition of cement concrete panel,then evaluate the pavement structure.After analyzing the reasons for the destruction of road in detail,author decided to take corresponding countermeasures for most sections. Impact compaction and grout repair technology are mainly used in this project. Measuring pre-processing and post-processing pavement deflection and bearing capacity at different approach,so it can analysis and evaluation of the reasonableness of approach.The article analyzes the stress state of asphalt overlay in vehicle load by a calculation of finite dement procedure ANSYS. These parametric variation including the thickness of asphalt overlay,the modulus of asphalt layer and the modulus of concrete layer,which have effect on the stress of asphalt overlay layer are analyzed . At the same time it verifies the rationality of design project on research pavement's overlay. This will provide some beneficial experience and references for project design of maintenance and reconstruction on the old cement concrete pavement later on.In order to better apply to reconstruction project,asphalt mixture type and mix design methods are mainly focused on improving the shear strength. Considering structural strength, surface features and overall cost-effectiveness,Stone Matrix Asphalt was used as the material of asphalt pavement surface layer. Construction quality control is the key link of reconstruction project. The asphalt mixing,transportation,paving and compaction have to meet specifications,so it can guarantee the achievement of quality standards for pavement acceptance.