Research On Durability Evaluation Index System Of Pavement Concrete In Cold Regions

Durability is extremely important for life of concrete. But in recent years, because of the load, construction, maintenance and other reasons, cement concrete pavement damage caused by lack of durability is very serious. Especially in cold regions, such damage phenomenon is common occurrence. The research on durability evaluation index system of pavement concrete in cold regions can provide a basis for durability comprehensive evaluation and life prediction and in turn to guide the durability design of pavement concrete in cold regions.That being the case, the key problem should be solved firstly is to establish index system that suitable for durability evaluation of cold regions pavement concrete. In this paper, relying on Qianfeng Farm-Nenjiang highway Longzhen-Nenjiang segment project, the regional background in Heilongjiang Province, conduct field surveys on durability damage status of cement concrete pavement in the regions, sampling conducte laboratory tests, analysis mainly reasons that lead to durability damage of pavement concrete in cold regions from materials level, and analysis durability damage mechanism combined with existing theories; On the foundation of determining durability damage reasons, targeted analysis durability evaluation indexes that relevant norms and previous studies mentioned, according to the principle of establishing index system, established draft evaluation index system, and optimized draft index system with the help of fuzzy prioritization method, combined with expert opinions, get the final durability evaluation index system of cold regions pavement concrete; Against freeze resistance and chloride-ion penetration resistance index of system, analysis index sensitivity using rapid freeze-thaw cycles method, straight line traverse method, electric flux method and RCM method, mainly through index relative value comparison each other to determine index sensitivity, find out sensitivity index for durability, divided it into two-stage evaluation index of laboratory stage and field construction stage according to the degree of difficulty or esae for project operation; Based on dynamic control principle, implementing dynamic monitoring to gas content and electric flux index of field construction stage for basic project.