Chloride penetration in reinforced slag-based concrete beams under combined effects of loads and drying-wetting cycles

Abstract

The use of slag-reinforced concrete is necessary due to environmental concerns around the world, but the decrease in concrete durability caused by chloride-ion rich environments requires more advanced concrete-mix designs, especially in coastal areas. This study aims to assess the influence of slag addition on chloride-ion transport performance in reinforced concrete beams under sustained bending moment, considering two conditions of environmental chlorine exposure: drying-wetting cycles and soaking. Results show that the chloride diffusion coefficient increases in tension zones and decreases in compression zones when the sustained bending load in concrete beams increases. However, the addition of slag can significantly reduce the chloride diffusion depth and diffusion coefficient values for both environmental conditions, with a more significant effect on the drying-wetting cycle. The chloride concentration on the surface of slag concrete (SC) in compression zones is greater than that in SC tension zones and that in ordinary concrete (OC) in both tension and compression zones. The study established a prediction model describing the chloride-penetration characteristics of concrete beams subjected to sustained bending moment. The proposed model is a reasonable approach for predicting chloride distribution in reinforced concrete beams with slag addition subjected to bending moments.