The Correction Model Of Diffusion Theory About Chloride Ion In Concrete And Its Numerical Simulation

Reinforced concrete structure is the most main structure form of construction engineering,its durability and life is affected by many factors,so the research of reinforced concrete structure durability and life has very strong practical significance and social needs.Reinforced concrete structure durability research is always an important hot topic in academia and engineering content,reinforced concrete engineering,high durability and long service life and with the state advocates energy conservation and emissions reduction and sustainable development is very fit.Caused by steel corrosion and concrete durability deterioration of engineering cases,the chloride ion erosion is caused inside the concrete reinforcement corrosion,the important factors in the coastal areas of national and saline area of bridge engineering,tunnel and other concrete structure damage is more serious.Based on comprehensive analysis of relevant theoretical results at home and abroad and the research and experiment on the theoretical analysis,formula deduction and numerical simulation,data analysis and other methods,the chloride ion permeability of concrete destruction process of reinforced detailed has carried on the deep discussion and study.The main research content is as follows:Paper first describes the damage of concrete structures at home and abroad,and summarizes the development of concrete chloride ion erosion model theory at home and abroad;Then based on the second Fick diffusion law,considering the concrete structure may be different,the chlorine salt erosion environment of chloride ion diffusion are influenced by a variety of internal and external factors,established considering time effect,chloride ion binding ability and the comprehensive factors such as temperature,stress state and fracture fixed chloride ion erosion model.Paper and combined with the related theory and mesoscopic fracture model of concrete structure,using the monte carlo method of randomness,the selection of aggregate gradation,such as theory,through the MATLAB software to establish the two-dimensional random aggregate model of concrete,for the fourth chapter of concrete chloride ion erosion COMSOL provide geometry model of numerical simulation.Considering effective chlorine ion diffusion coefficient changing with time,temperature and other external conditions of the complexity of the selection of model parameters,using COMSOL software on concrete chloride ion erosion process and numerical simulation and analysis,comparison,confirmed that the finite element software COMSOL the rationality and validity of the simulation process of the chloride ion permeability of concrete.Combined with numerical simulation data and concrete chloride ion migration mechanism,puts forward the prevention of chloride ions into the concrete and effective measures,provides a theoretical basis for the engineering construction,also provides a convenient for the engineering construction.