EFFECT OF CFRP STRIPS BONDING LOCATION ON FLEXURAL CAPACITY AND DUCTILITY OF REINFORCED CONCRETE BEAMS

Strengthening reinforced concrete beams using laminate of advanced composite materials has gained ground recently due to its lower cost and simplicity compared to traditional methods. These traditional methods are usually done by either increasing the reinforcement or the beam’s dimensions, which naturally requires formwork, and hinder the structural usage. One of the most impediments of using bonded laminate in strengthening beams is debonding. In flexural strengthening of beams, this debonding occurs via mid-span debonding or end-delamination of the laminate. Herein, ten RC beams were experimentally tested in flexure under three-point loading. The reinforced concrete beams have rectangular cross sections and were strengthened by bonded CFRP strips. Flexural strength and ductility were investigated in order to reveal the impact of changing the CFRP strips’ locations with respect to the beams’ cross section. The CFRP strips were attached to the reinforced concrete beams sides of bottoms. The first configuration is thought to reduce the effect of flexure cracks in the mid-span of the beams, which may delay the deboning of these laminates. In order to anchor the strips, close to the support and eliminate end delamination, CFRP sheets were wrapped at these locations. Based on the proposed configurations, the flexure strength of the beams increased by an average of 40%.