Investigation of Short-Term Deflection in Reinforced Concrete Beams with FRP Bars

One of the most important factors affecting the serviceability of structures is the deflection of concrete members. In this paper, short-term deflection of reinforced concrete (RC) beams with FRP and steel bars were studied by modeling in ABAQUS software. For different types of steel and FRP bars, twelve RC beams have been analyzed and the effective moment of inertia and deflection of the results were compared with the ACI 440.1R-15 and proposed equations. After analysis, it was found that to prevent sudden failure of RC beams with FRP bars, it is better to design a concrete beam with over reinforced sections. According to load-deflection curves of RC with FRP bars, the use of carbon FRP (CFRP) bars are the suitable alternative for steel bars in the corrosive environment. It is concluded that the use of Bischoff- Scanlon, and Bischoff- Gross equations in RC beams with glass FRP (GFRP) and aramid FRP (AFRP) with the error of less than 2% and 10%, respectively, are appropriate for determining deflection in these beams. Results indicate that any of the proposed relations for all different types of FRP rebar does not provide satisfactory results and in terms of used reinforcement special equations should be used.