Effect of corrosion damage on the flexural performance of RC beams strengthened with FRCM composites

This paper reports on the flexural behavior of corrosion-damaged reinforced concrete (RC) beams strengthened with different fabric-reinforced cementitious matrix (FRCM) composites. Three groups of beams were subjected to accelerated corrosion for 70, 140, and 210 days to obtain theoretical mass loss in their tensile steel bars of 10%, 20%, and 30%, respectively. The test parameters included the fabric type (PBO and carbon), the number of FRCM layers (two, three, and four), and the strengthening Scheme (end-anchored and continuously wrapped). Test results showed that FRCM composites governed the failure of the strengthened beams rather than the damage level to which the beam was subjected due to corrosion. The reported load-carrying capacities of the corrosion-damaged beams confirmed that the contribution of FRCM composites significantly offset the impact of corrosion damage on strength. FRCM-strengthened beams exhibited an increase in strength that ranged between 7 and 55% of that of the virgin beam based on the type, the axial stiffness, and the Scheme of the FRCM used. The strengthened beams showed energy absorption indices that ranged between 111 and 153% of that of the virgin beam. The theoretical formulations of ACI-549.4R-13 reasonably predicted the ultimate strengths of the end-anchored strengthened beams but underestimated those continuously anchored beams.