| With the rapid development of China’s economy,the number of vehicles increased significantly,the carrying capacity of freight vehicles also increased,and with the increase of the service life of the highway,the cement concrete pavement constructed in the early period of our country can no longer meet the needs of the situation of modern traffic development.Therefore,quite a number of cement concrete pavement using asphalt overlay this composite pavement structure for upgrading.The maintenance problem of white plus black composite pavement has become an urgent engineering problem to be solved.Therefore,based on the tanlei expressway composite pavement project,the maintenance problem of the composite pavement is systematically studied after the reconstruction and reconstruction of the previous project.In this paper,first of all,the original cement concrete pavement of tanlei expressway is investigated and analyzed from the aspects of drainage of subgrade and pavement,pavement usage,including the status of pavement broken slab,slab bottom void,base integrity,equivalent modulus of resilience of base top surface,etc.Investigation found that the side ditch water cross-section larger,to meet the drainage needs of the roadbed,side ditch overall good condition,not many damaged sections,drainage system is more perfect.However,the drainage system in the middle belt is blocked seriously,which makes the water in the middle belt seeping into the roadbed on both sides,and becomes an important cause of pavement damage.For the use of the pavement,the original cement pavement is mainly broken disease,broken loose base and poor supporting uniformity.On the whole,the pavement condition is damaged seriously.Secondly,the paper summarizes and analyzes the cement concrete overlay asphalt pavement composite pavement reconstruction scheme.By comparing several different paving schemes,the main road paving scheme is as follows:4cm sma-13+5cm modified asphalt ac-20+1cm modified asphalt synchronous crushed stone seal layer+18cm continuous reinforced concrete+2.5cm ac-10 isolation layer+old concrete slab replacement grouting comprehensive treatment.The total thickness of overlay is 30.5 cm.Then,the composite pavement diseases after the reconstruction are investigated and analyzed,and the types,proportion and distribution of the diseases under the heavy load are summarized,and the causes of the diseases are analyzed;It was found that the main disease types were loose,accounting for 66.78%of the total diseases;Finally,comprehensive evaluation is made from three aspects:PCI,RDI and RQI.According to the evaluation results and traffic volume and rainfall of the highway,the optimal maintenance scheme is put forward to adapt to tanlei high speed composite pavement. |
