Numerical Study on Flexural Behaviour of Steel-GFRP Hybrid-Reinforced Concrete Beams

To alleviate the corrosion issue, GFRP bars are usually preferred over steel reinforcing bars. However, its application causes larger deflection and brittle failure of concrete members. To solve this, steel bars can be used in combination with GFRP bars to reduce deflection and enhance ductility. Steel-GFRP hybrid reinforced concrete is a relatively recent concept, as a result, it is still in the development stage. This study numerically examines the flexure response of concrete beams reinforced with hybrid reinforcement i.e., GFRP bars combined with steel. A total of five numerical models were developed for this investigation. The analysis methodology is based on the models developed for investigation of GFRP reinforced concrete beams which was validated with experimental studies. It is found that with an increase in the replacement percentage of steel in GFRP RC beams, the ultimate load is increased. Also, it is observed that there is a significant reduction in deflection in post-cracking and pre-steel yielding region along with enhancement in the attributes of ductility which is beneficial for serviceability aspects. The steel-GFRP hybrid-reinforced concrete beams were found to have failed by yielding of steel and subsequent concrete crushing.