Shear behavior of RC beams strengthened with different types of FRCM: Effect of stirrups' configuration

Abstract

Fabric-reinforced cementitious matrix, (FRCM) system has shown to be promising for the strengthening of reinforced concrete (RC) beams. However, the available experimental investigation on the shear strengthening efficacy of FRCM system is limited, particularly for deep beams. Moreover, to the authors' knowledge, no literature is available on the effect of the stirrups' configuration relative to the FRCM strips on the shear capacity of FRCM-strengthened beams. Studying this effect will aid in a better understanding of the FRCM/stirrups interaction. Thus, in this paper the experimental study on the shear behavior of RC deep beams strengthened in shear using FRCM system is presented. The test matrix involved two unstrengthened and six FRCM-strengthened deep beams tested under three-point bending. The primary test variable was the effect of stirrups' configuration relative to the FRCM strips. The other test variable includes the effect of different types of FRCM fabric (made of carbon, glass, and polyparaphenylene benzobisoxazole, PBO). Experimental results demonstrated an effective application of the FRCM in improving the load capacities of RC deep beams, up to 40.3% increase in the load capacity was achieved.