Study On Evaluation And Countermeasures Of Durability For Existing Railway Concrete Bridges

The too fast deterioration has been a critical problem faced by concrete structures, and the durability of concrete has been more and more written into design and construction codes. This thesis generalizes the determinants influencing the durability of concrete simply-supported girder bridge and combines with the analytical hierarchy process and fuzzy integral evaluation to carry out the evaluation of durability of concrete simply-supported girder bridge. The main contents include:1. The author analyzes the problems faced by concrete structures, discusses the research contents of durability of concrete bridge structures and the current research states of the world and describes the definitions, contents, and methods of bridge durability evaluation.2. The author discusses the determinants influencing the durability of concrete bridge, including alkali-aggregate reaction, steel bar corrosion, chloride ion corrosion, concrete carbonization, freeze-thaw cycle, etc. The author concludes the preventive measures aiming at various disease and main ways integrally increasing durability of concrete bridge.3. The author analyzes and describes the analytical hierarchy process, fuzzy integral evaluation, and their applications in durability evaluation of concrete simply-supported girder bridge, establishes an evaluating model of concrete simply-supported girder bridge.4. The author exploits the durability evaluation system of concrete simply-supported girder bridge, and applies the system to evaluateexisting bridges.5. The author discusses various methods of maintenance and repair ofconcrete structure.