Service Life Prediction Model of Concrete Square Piles in Marine Environment

Abstract:

A diffusion equation of chloride ion in concrete was put forward based on Fick's second law. In the equation, the influences of timedependence of chloride diffusivity, the effect of load on diffusion coefficient and chloride ion binding capacity of concrete were taken into consideration. A prediction model of service life of reinforced concrete (RC) square piles was established. The effects of cover thickness, cracking width, surface chloride ion concentration and the chloride threshold level on service life of RC square piles were analyzed. The analysis results indicate that the diffusion equation of chloride ion of this paper agrees well with the experimental data. It suggests that the cover thickness should be greater than 45 mm and the cracking width should not be greater than 0.1 mm if the design service life of RC square piles is 50 years.