Using CFRP for Enhancing of Circular Cutout in High Strength RC Deep Beam

Abstract

This paper presents the results of an experimental investigation of the using of carbon fiber reinforced polymer (CFRP) to enhance the high strength reinforced concrete (RC) deep beam in case of creating a circular cutout throughout its web. A set of 5 specimens were grouped and investigated to evaluate the structural behavior in terms of shear strength capacity and deflection. The specimens were 1200mm long with rectangular cross-section of 100x500mm. Two symmetric circular cutouts of 150mm diameter were made at midpoint of each shear span. CFRP strips were installed around the cutouts in three different configurations in order to enhance the cutout zone. The results of this experimental work showed that the diagonal configuration of CFRP strips around the cutout was the best one, as the ultimate shear strength ratio with respect to control solid beam was 0.97, while it was 0.86 for control beam with cutouts. A significant positive effect was observed on the deflection for the beams that enhanced with CFRP strips. Also, CFRP sheet oriented diagonally around cutout was the most appropriate for reducing the deflection.