Durability Design And Experimental Study Of Concrete Structure In Littoral Environment

The durability of concrete structure has great influence on the service performance and service life of bridge structure,therefore the research has been paid much attention.In order to explore the durability of the concrete bridge structure in the coastal environment,the paper studies the impact of the load level on the chloride ion infiltration,durability design based on chloride ion erosion model and carbonization model,mix design of long-life anti-corrosion concrete and study of anti-corrosion measures in coastal environment,which all based on practical durability design of Humen No.2 Bridge.The main research work and results is as follows:(1)This paper introduces the importance of concrete durability in coastal environment and the application of concrete anti-corrosion technology.The influence of corrosion medium and stress on the durability of concrete is introduced,which can provide reference for the durability design of background engineering.(2)The causes of the decrease of the durability of reinforced concrete are analyzed,and two kinds of erosion model and various durability design methods are introduced.(3)The relevant field investigation is carried out according to the environment of Humen Bridge,.According to the research data combined with the chloride ion erosion model and the carbonization model,the laboratory carbonation depth control index,protective layer thickness and chloride ion diffusion coefficient control index of 100 years service life concrete in the coastal environment are obtained.And also the impact of load to chloride ion permeability is studied by simulating the actual load environment.The results show that when the flexural load increases to a certain extent,the migration coefficient of chloride ions in the concrete increases,and compressive load has little effect on the chloride ion migration coefficient.(4)The concrete raw materials is chosen by hydration test and cracking sensitivity test of various cementitious materials system.and then the basic match ratio of concrete mix is obtained by workability test,mechanical test,chloride ion resistance test.Finally,according to the test results,the design,adjustment and re-inspection of the concrete of Humen No.2 Bridge is catch out.(5)This paper summarizes the commonly used anti-corrosion measures of the concrete structure of the bridge concrete in the coastal environment,the performance and economic benefits of the three kinds of release agents are analyzed and evaluated,and then the durability life of the key parts are calculated by selecting the carbonization depth and the chloride ion diffusion coefficient as the index.The results show that the comprehensive utilization of silicone resin in the coastal environment is the best in economic efficiency.In addition to the anti-collision barrier,the other concrete structures of Humen No.2 Bridge can meet the 100-year design requirement without any external anti-corrosion measures.