Post-repair flexural performance of corrosion-damaged beams rehabilitated with fabric-reinforced cementitious matrix (FRCM)

Abstract

This paper presents the results of a research program examining the post-repair flexural response of corrosion-damaged reinforced concrete (RC) beams repaired with different FRCM systems. A total of nine RC beams were tested, including two beams that were neither corroded nor repaired, one beam that was corroded and not repaired, and six corroded-repaired beams that were prepared in two phases. Beams of phase I were subjected to an accelerated corrosion process for 210 days before being repaired whereas beams of phase II were initially subjected to accelerated corrosion for 70 days, then repaired and exposed to further corrosion for 140 days. Flexural test results showed that exposing the FRCM-repaired beams to corrosion after repair resulted in 23% reduction in steel mass loss. The use of U-shaped FRCM layers was more efficient in reducing the corrosion rate and increasing the ultimate strength of the repaired beams than the end-anchored FRCM layers. The PBO FRCM-repaired beams showed lower post-yielding stiffness and more ductility at failure than those of their carbon FRCM-repaired counterparts. Beams that experienced post-repair corrosive environment showed load-carrying capacities that ranged between 14 and 65% above those of the virgin beam. ACI 549.4R-13 provisions conservatively predict the ultimate capacities of the FRCM-repaired beams exposed to post-repair corrosive environment.