Chloride Ion Transportation And Life Prediction Of Concrete Under Combined Action Of Load And Service Environment

It is not uncommon for concrete structures to deteriorate due to insufficient durability and then fail to reach the design service life.At present,there are relatively mature studies on the deterioration of concrete structures under the action of single factors such as chloride ion erosion at home and abroad,but most of the concrete structures in actual engineering are in service under the combined action of load and environment,which must be significantly different from the deterioration law of concrete under the action of single environmental factors,and the combined effect of load and environmental factors is not a simple superposition of various factors.Therefore,it is of great significance to study the transport and change law of chloride ions inside concrete under the combined effect of load and service environment for the life dynamic prediction of practical concrete structures.The main research contents of this paper are as follows:(1)Study of chloride ion transport in concrete under the combined effect of load and service environment.The Lagrange equation and the control equation of chloride ion transport under load and service environment are established.The diffusion of chloride ion in concrete is simulated and verified by COMSOL software.Simulation studies and analysis of chloride ion transport in concrete under the combined of load alone,load and temperature,load and freeze-thaw cycles,and load and electric field were also carried out respectively.(2)Study of chloride ion transport in self-healing concrete under the combined effect of load and service environment.Considering the time-varying chloride ion diffusion coefficient of self-healing concrete,a simulation study of chloride ion transport in self-healing concrete under the combined effect of load and service environment is conducted.(3)Whole-life prediction study of concrete structures under the combined effect of load and service environment.Based on the whole-life design theory of concrete structure,combined with the concrete life prediction model under the combined of load and service environment,the service life of concrete under the combined of simple load,load and temperature,load and freeze-thaw cycles,load and electric field is predicted and analyzed.Based on the principle of concrete durability monitoring and electrochemical monitoring technology,According to the whole life prediction route of concrete,the concrete life is dynamically evaluated and modified.