Use of high strength Strain-Hardening Cementitious Composites for flexural repair of concrete structures with significant steel corrosion

Abstract

Steel corrosion is a major cause of deterioration for reinforced concrete structures, leading to significant area loss of rebars that affects structural safety. The most common repair approach is to splice additional reinforcements to the corroded rebars, which is time consuming and costly, as a large volume of sound concrete beyond the corroded part must be removed to provide sufficient lap lengths. The present study explores a new repair technique using high strength Strain-Hardening Cementitious Composites (SHCC) in the aforementioned situation. With SHCC compensating for the area loss of rebars, splicing additional reinforcements or removing a large amount of concrete is not necessary. In this paper, the design of high strength SHCC was first discussed. Then, rebars with reduced area were embedded inside SHCC blocks and tested under direct tension. Further, beams containing rebars with reduced area and patched with SHCC were tested under four-point bending. The test results at different scales verify the feasibility of the proposed repair technique which is more efficient and less costly. The findings of this study can support future repair applications using SHCC.