Experimental study on the flexural behaviour of corroded concrete beams reinforced with hybrid steel/GFRP bars

The high strength, corrosion resistant, and nonmagnetic characteristics of glass fibre reinforced polymer (GFRP) bars make these bars suitable for use as reinforcement in concrete structures exposed to aggressive environments. This article presents an experimental study on the flexural behaviour of hybrid (SGFRP) concrete beams reinforced with steel and GFRP bars. Six concrete beams measuring 150 x 200 x 2200 mm were fabricated, two of which were normal reinforced concrete (RC) beams and four of which were reinforced with either a hybrid combination of steel and GFRP bars or GFRP bars only. An accelerated corrosion test using the electro-chemical corrosion method was conducted on the RC and hybrid beams until cracks appeared on the beam surface due to steel bar corrosion. Subsequently, a four-point bending test was conducted on the corroded beams until point of failure to assess the flexural behaviour of the corroded SGFRP concrete beams. The experimental results demonstrate that corroded and non-corroded SGFRP beams exhibit similar flexural behaviour and highlight the role of GFRP bars in distributing flexural cracks and in increasing beam load-bearing capacity. In addition, a simple model was proposed based on the obtained experimental results to predict the load-carrying capacities and load-deflection curves of corroded SGFRP concrete beams.