Study On The Performance Evaluation And Preventive Maintenance Decision-making Of Expressway Asphalt Pavement

Highway transportation is the basis for national economy development and a very important symbol of a country's level of modernization. Pavement performance is an important part which embodies the service level of highway, the evaluation of pavement performance is one key to understand the pavement condition and a sound basis to construct reasonable maintenance plan, in the mean time, it is also the key to establish and realize the pavement management system. As an active maintenance pattern, preventive maintenance can fulfill the requirement of current maintenance and management of asphalt pavement much better.This paper focuses on the evaluation methods of expressway asphalt pavement performance.Based on the COST(European COoperation in the field of Scientific and Technical Research)354 system, this paper puts forward the single and combined index of asphalt pavement performance,and improves some of the indexes and methods according with some characters of SiXiao expressway. Meanwhile, according to comparing the evaluation results of COST354 and Chinese standard, it analyses the differences between these two methods and the specific reasons caused by these differences.Based on the limitations of the existing division method, this paper introduces the fuzzy mathematics theory to clustering method in order to establish a segments division which named the fuzzy clustering analysis method.With SFC(Side Friction Coefficient), SSI(Structure Strength Index), IRI(International Roughness Index), RD(Rutting Depth) and PCI(Pavement Condition Index) as the statistical indicators, the method can avoid the limitation of "black-and-white" and improve the accuracy when it is used in the pavement segment division.This paper chooses crack length, friction coefficient and roughness index to establishs a model for pavement segment division and finally illustrates with an example of SiXiao expressway.Based on Chinese standard, the paper has determined the scope of the expressway asphalt pavement feasible to take preventive maintenance with some combined indicators which are chosen from COST354. Then it selects the maintenance project for representative section of SiXiao expressway with multi-level fuzzy decision method, and finally prioritizes maintenances for three highways in Yunnan province with two methods.Finally, this paper incarnates their advantages and disadvantages respectively with comparing and analysing performance of the roads which were taken actions of micro-surfacing, sealing coat, fog coat and reductant sealing coat before-after the republic.