ADVANCED ANALYSIS OF CHLORIDE DIFFUSION AND CONVECTION IN CONCRETE STRUCTURES

摘要

On the basis of the transport mechanism of chloride ions, a prediction model of chloride penetration into concrete structures has been developed. The model includes the diffusion of chloride and its dependences on temperature, age, relative humidity, chloride binding and chloride convection by moisture transport. The experimental programme has been set up to verify the model developed in the present study. Several series of concrete specimens were immersed in 3.5% chloride solutions for 15 weeks, and the chloride profiles of the specimens were measured and compared to the predicted chloride profiles. In addition, field measurements were also conducted. From a 10-year-old bridge, the chloride profiles of the tidal zone were measured and compared to the predicted chloride profiles. The comparison of the laboratory and field test results with theory confirms that the model developed in the present study can be realistically used to predict the penetration of chloride ions into concrete structures under marine environments.