Studies On The Durability Of Reinforced Concrete Structure Exposed To Soil And Groundwater Environment

There are two parts in this dissertation. One is about the interaction and mechanism of carbon dioxide, sulfate and chloride in process of deteriorating reinforced concrete. Another is about the experimental study on the durability of pre-tensioned prestressed concrete pipe pile.Carbon dioxide, sulfate and chloride are three significant factors causing the deterioration of reinforced concrete structures and they are interactional. This dissertation summarizes some related literatures and information, enumerates many phenomenas of the interactions of those three factors and analyses the potential chemical mechanism. Combining the study on the performance of RC pile foundation in a certain electricity generating station in Zhenhai, the dissertation gives some conclusions about the interaction and mechanism of carbon dioxide, sulfate and chloride in the course of deteriorating reinforced concrete, and explains the phenomenas above metioned. Those result may be valuable for the reference to the RC structural durability.The pre-tensioned prestressed concrete pipe piles have been widely used , yet without experimental investigation conducted to evaluate their durability by far. Especially for the PTC piles with thin-walled concrete cover, it is a issue worthy of research and discussion that whether the thickness of the concrete cover is proper and meet the demand of the structural durability and long-term service performance. The Institute of Structural Engineering, Zhejiang University, has made a mixed liquid to simulate the attacking media of the underground environment and enlarge the concentration of the environmental solution for the purpose of accelerating the degradation of the specimens. From the result of the experimentation the chloride diffusion coefficient of concrete of the pre-tensioned prestressed concrete piles is calculated which may embody the penetrability of concrete. Combining different environments the pipe pile's service life is estimated and thus the scope of the application of the pipe pile is suggested.The studies of above two subjects make us get known with the interaction and mechanism of carbon dioxide, sulfate and chloride in process of deteriorating reinforced concrete more distinctly, and discover the complex action between ambient medium and concrete as well as the cement and concrete chemistry. It provides us with some beneficial enlightenments which may be useful in improving the durability of the concrete structural durability. While the study the on the durability of pre-tensioned prestressed concrete pipe pile is the first at home yet, and it has significant reference value for the application and popularization of the pipe pile which is just in the ascendant.