Research On Carbonation Of Concrete Materials In Qinghai's Salt Lake

The concrete carbonization is one of the main factors which cause corrosion of reinforcement in concrete. Reinforced concrete usually occurs corrosion seriously in a few years in salt lake of China's western region, thus seriously affect safety and durability of the structures, and it also cause a great economic losses and the waste of resources. Because of the demands of western development strategy, some bridges and roads must be built through the salt lake area, therefore,how to protect concrete in salt lake from being corrupted and improve its durability become a heated and difficult problem in the research of theory and pratical projects.The paper researches on carbonation of concrete materials in Qinghai's salt lake. Mixing or smearing waterproof materials can inhibit the corrosion of harmful icons to concrete. The paper observes and analyses the improvement of concrete carbonation, and then speculate the improvement of durability of concrete after being taken anti-corrosion measure.The paper chooses an material called XYPEX as the ideal one,then through the simulation of environment of Qinghai's salt lake, this paper uses natural freeze-thaw circulation and indoor fast carbonization test to compared carbonation depth of concrete without any treatment with the concrete which is after XYPEX handling (including the mixing and the smearing). According to the test results, the paper uses least-square method to fit out carbonation depth of various types of concrete, then builds the mathematical model of concrete carbonation. The paper apply the concepts of incomplete carbonation zone and carbonation remains to predict the carbonation life of different type of concrete. The paper also uses BP network of Matlab6.5 to predict the carbonation depth of concrete. Test results and analysis show that the usage of XYPEX as anticorrosion material in Qinghai's salt lake area can significantly improve the performance of concrete carbonation. Between them, the method of smearing XYPEX is more effective. Therefore, in order to improve the durability of concrete, it should use XYPEX in concrete of Qinghai's salt lake reasonably. Otherwise, carbonation depth of concrete can be predicted well by using BP network reasonably. Through the experiment, this paper also find that the chloride diffusion have much influence on the corrosion of reinforcement in concrete. Therefore, the paper assumes that it has important meaning to focus on chloride diffusion in the research of corrosion of reinforcement in salt lake much more.