Effect of pre-loading on chloride diffusion in concrete

Abstract

This study concerns experimental works to examine the effect of pre-compressive stress on chloride diffusivity in concrete. Three types of concrete (C1, C2, C3) with different compressive strengths were examined in two environmental conditions (spray zone and atmospheric zone). Four different stress levels (0%, 30%, 50%, and 80 % of the stress at ultimate load) were applied to 100 mm diameter concrete specimens. After loading and subsequent, specimens were treated and put into chloride diffusivity cell of rapid chloride permeability test based on the ASTM C1202 test. Chloride diffusion coefficient of concretes was calculated from those results considering the effect of pre-compressive stress. The experimental results show that the chloride permeability increased with the increase in pre-compressive stress. A correlation between the relative diffusion coefficient of pre-compressive to non-load (Dσ/D0) and the pre-compressive stress levels for each of the concrete type was obtained in this experiment. Finally, these values were used for predicting the corrosion initiation of rebar in reinforced concrete structures.