Development of the corrosion-filled paste and corrosion layer at the steel/concrete interface

This study investigated four types of concrete that had deteriorated by wet-dry cycles coupled with DC power. The thicknesses of the corrosion-filled paste, T-CP, and the corrosion layer, T-CL, were measured by SEM in backscattered electron mode. A sudden increase of T-CP near the inner crack is observed. As T-CL grows, T-CP develops gradually until T-CL reaches a certain value, afterwards T-CP remains nearly unchanged. Considering the inner cracks, which reflects the actual situation, k(T) and T-CP(max) in the T-CP-T-CL model grow with increase of recycled aggregates replacement; while the rule is contrary if excluding the inner cracks. (C) 2014 Elsevier Ltd. All rights reserved.