Structural Property Assessment of GFRP Reinforced Concrete Beams

Abstract

Steel making process exhibits greater environmental impact, including emission of greenhouse gases, wastewater contaminants and solid wastes. Further, steel corrodes rapidly in aggressive environment. Corrosion has a major impact on the life of the structure and thus affects the overall economy in the reinforced concrete project. Glass fibre-reinforced polymer (GFRP) bars provide a satisfactory solution to some of the environmental problems associated with conventional steel. As compared to steel, GFRP rebar has higher strength and good corrosion resistance but exhibits brittle behavior; therefore direct replacement of steel is not always possible with GFRP rebars. The present study examines the flexural behaviour of steel and GFRP reinforced concrete (RC) beams wherein four different reinforcement configurations are considered. Norms in compliance with ACI440.1R-06 have been used in design of specimens carrying GFRP rebars as internal reinforcement. Steel RC beams of M30 and M35 grades are used as control specimens. A total of 32 beams were tested in flexure; the load-deflection response, ductility, energy absorption, cracking patterns and the failure modes were recorded. A comprehensive analytical analysis was conducted to predict the ultimate loads of test beams. The test results evinced that the performance of the proposed configurations was successful in maintaining the flexure strength. ACI440.1R-06 based formulas can fairly be used to predict ultimate deflection values of GFRP RC beams. GFRP RC beams showed much wider cracks before failure but lower ductility than steel RC beams.