Shear strengthening of RC deep beams with sprayed fibre-reinforced polymer composites (SFRP) and anchoring systems: part 1. Experimental study

This paper presents an experimental study on externally bonded sprayed fibre reinforced polymers (shortly as SFRP) RC deep beams to investigate the efficiency of SFRP in shear strengthening. Based on the experimental results, reinforced concrete deep beams strengthened by SFRP composites may fail by debonding of SFRP from the beam surface. To avoid such failures, various forms of anchoring systems have been proposed and tested to evaluate their performances in preventing the delamination of SFRP from concrete surface. A series of three-point loading tests was conducted on SFRP strengthened deep beams. The research parameters included SFRP material (glass and carbon), thickness, configuration, i.e. SFRP applied onto two or three sides, compressive strength of concrete and types of anchoring systems. Proposed anchoring systems (Through Bolts, Mechanical Expansion Bolts and Epoxy Chemical Bolts) were found to be effective to prevent the delamination of SFRP. Test results indicated that SFRP was capable of enhancing the ultimate load and deflection of RC deep beams provided that adequate anchoring system is installed. The performance of SFRP strengthening depends on several key variables such as SFRP material, thickness, strengthening configuration, strength of concrete, type of anchoring system and length of the anchor bolt.