Study On Chloride Ion Permeability Of Concrete In Nuclear Containment

The durability of concrete structures require more stringent due to security requirements of the nuclear power plant. The chloride ion erosion under marine atmospheric environment is the critical influence factors of nuclear power containment concrete durability failure. There inevitably exist lots of piping hole due to the need of cooling and process of nuclear power containment. However, the existence of pipe holes damage the integrity of concrete structures, thus becoming the breach of the chloride ion erosion of concrete, which greatly influence the durability of the nuclear power plant concrete structure. Therefore, this thesis has great significance for the research on the rule of chloride ion erosion of the concrete within the pipeline under interaction in marine atmosphere and high temperature environment.In this thesis, the current research on chloride ion permeability of concrete is described, and the deterioration mechanism of concrete durability under chlorine ions is elaborated, then the chlorine ions accelerated experiment and theoretical analysis is adopted. The pipeline of containment is simulate, six different diameter hole of concrete pipe specimens are designed and perform the accelerated experiment of electric flux, chloride ion diffusion, chloride ion erosion under high temperature, which simulate chloride ion erosion of the nuclear power concrete specimen under interaction in marine atmosphere and high temperature environment. The measurement data including the electric flux of hole, the chloride ion diffusion coefficient of concrete and chloride ion penetration depth. Through test analysis and theoretical studies, it is concluded that the chloride ion erosion rule of the concrete within pipeline under heterogeneous environments.The main research conclusions in this thesis are as follows: Firstly, the pipeline hole has an adverse effect on concrete resistance to chloride ion penetration, the hole diameter is larger, the ability to resist chloride ion permeability of concrete is weaker; Secondly, the equation between the diameter of pipeline hole and concrete electric flux with the chloride ion diffusion coefficient is set up; Thirdly, the equation between hole concrete electric flux and the chloride ion diffusion coefficient is established; Fourthly, it is concluded that the chloride ion erosion rule of concrete under high temperature; Finally, the chloride ion erosion model of the concrete within the pipeline under interaction in marine atmosphere and high temperature environment is established.