Case Study On Condition Evaluation And Pavement Rehabilitation Technology For Expressway

With the rapid development of domestic expressway,the network dominated by Asphalt Pavement Structure has been basically built.However,due to high frequency of pavement disease such as asphalt pavement cracks,water damage and tracing rut,etc,the existed expressway has been getting into a comprehensive maintenance and repairing stage.How to achieve economic,scientific,efficient evaluation and repair of the pavement is an important subject for study and research.This paper summarizes the contents and basic theories of highway usage assessment and restoration decision-making: Highway condition assessment includes three parts: traffic survey and analysis,assessment and analysis of treatment quality for soft ground section,evaluation and analysis of asphalt pavement usage condition.Through data collection,on-site inspection and survey,it helps to obtain the sub-grade and pavement condition.By analyzing and assessing of the collected data,it make clear the causes of pavement disease and the formation mechanism of actual pavement situation.Pavement repair is feasible recovery programme based on the comprehensive factors such as usage condition,structure bearing capacity,functional features,drainage system,etc.,carrying out scientific guidance of road maintenance and alteration.Taking the second-phase project Chen Cun to Xiqiao of Guangming Expressway as evidence and study,through the analysis and forecast of the old road traffic volume,the quality evaluation of the soft foundation after construction,and the comprehensive evaluation by the four evaluation indexes as PCI,RQI,SFC or BPN,SSI,,it determines whether the sections meet the standard of subsequent use.Based on the evaluation of the use condition,carrying out calculation with the asphalt-pavement structure design and the old road condition under forecasting traffic flow,it puts forward several feasible schemes.Then it economically analyzes the influence on the soft foundation and the equivalent axis times to determine the preferred repair program and further discusses how to carry out evaluation of the expressway use condition and decision-making of the road surface restoration comprehensively,scientifically and objectively.Based on the theoretical summary and case study of road condition assessment and restoration decision,it points out that the scientific and comprehensive assessment and repair of the old road should based on the evaluation and analysis on the performance of the subgrade,pavement and bridge,combined with the calculation of the traffic intensity and program selection to determine the priority repair program.