Durability Evaluation And Life Analysis Of The Existing Reinforced Concrete Bridge

In the natural environment and the long-term usage conditions, reinforced concretebridge will deteriorate, damage and even have the serious damage because of the problems instructural design, construction and maintenance management, this will affect the safety andsuitability of the structures directly. Therefore, assessment and prediction of the durability ofthe existing reinforced concrete structures has become an urgent problem which need to besolved. Based on the existing durability research theory of reinforced concrete structures, themain research contents are as follows:(1) Based on a large number of research literature at home and abroad， the major factorof affecting the durability of reinforced concrete bridges have been analysed in this text, suchas carbonation of concrete, steel corrosion, alkali-aggregate reaction, concrete freeze-thawcycles, chemical erosion and concrete surface wear.(2) Based on the mechanism analysis of the durability, to study the durabilityassessment of concrete structures from two aspects of the mechanical performance of concretestructures and durability grade. Mainly analyzed the mechanical properties of steel corrosionon components, and through the finite element software to simulate the force of the corrodedreinforced, using the spring elements to simulate the bonding between the reinforcement andconcrete, and consider the yield strength reduction after the steel corrosion finally, accordingto the structure of the weight of components to assess durability grade with the fuzzycomprehensive.(3) Based on the durability disease characteristics of concrete structures, to predict theservice life of concrete structure, which mainly includes the normal service life assessmentand carrying capacity life assessment, using concrete carbonation life standards, rust bilgecracking life criteria and the carrying capacity life criteria. According to different criteria, toput forward the calculation model of the dynamic reliability, give the values of the randomparameters, and describe the specific steps and methods with a practical example.(4) On the basis of the previous chapters, based on the durability disease characteristicsof concrete structures, to make some improvements from the concrete structure design,construction and operations management, in order to improve the durability of concretestructures and provide a reference for the subsequent structural design, construction andmanagement.