Durability Status Research For Existing Concrete Structure In Chongqing

Reinforced concrete structure is the most widely applied structure in almost different parts of the world; but concrete structure is not as durable as people expect. The research of durability of concrete structure had become a focus in the field of structural engineering home and abroad. So it is very practically significant and economically valuable to evaluate the durability of concrete structures in service.Durability engineering of concrete structures in Chongqing is the research object in this dissertation. The durability status of concrete structures in Chongqing is discussed based on the analysis of the influence of climate condition and structure design and construction on concrete structure; through the durability examination of one project some formulas of <> are validated. Based on the combination quality analysis and quantity calculation, durability assessment method of concrete structure is studied.The main studies of this dissertation are as follows:1) The influence of temperature and humidity and acid rain on concrete structures in Chongqing are analyzed . Based on the engineering examples the influence of structure design and construction on concrete structures are analyzed. The durability status of concrete structures in Chongqing is discussed based on the analysis of the depth of concrete carbonization and the thickness of concrete cover and reinforcement corrosion.2) The concrete basic member (including beams and columns) durability examination and experiments have been carried out to study the durability law in the natural environment, and the factors affecting the durability of concrete members are discussed. On the basis of the result of durability examination, the durability of concrete structure is evaluated by fuzzy sets and the analytic hierarchy process. It indicates that the assessment result matches the actuality through contrasting assessment result with examination result.The conclusions have obtained in this dissertation are as follows: The durability of concrete structure is characterized by complexity and variety. It is necessary to guide design and construction and reinforce through the analysis of local climate conditions and durability status of concrete structures. It turns out that the durability status of concrete structures in Chongqing is not satisfying. The climate condition in Chongqingis negative, and reinforcement corrosion appears too early. It is hidden trouble in structure which environment factor is not fully considered in design, thus the durability damnification of structure appears too early because of inferior construction. The measures and methods of inspection are out of date, and the result of inspection is incomprehensive and inexact. In this dissertation, the calculation formula for depth of concrete of carbonization of <> is proven valid. The durability of concrete structure is evaluated based on the combination of fuzzy sets with the analytic hierarchy process. The assessment result matches the actuality, which indicates this method is valid to evaluate the durability of civil engineering.