Experimental and Analytical Study of Flexural Capacity and Deflections of Concrete Beams Reinforced with BFRP Bars

Abstract

The good and proven advantages yet of basalt fiber reinforced polymer (BFRP) bars,  in terms of mechanical properties and economic benefits due to the abundance of raw material (basalt rocks) required for the production of basalt fibers, which is the main component of these bars, make them a promising alternative to other reinforcing bars of FRP compounds. However, due the recent emergence of these bars and the incompleteness of studies related to the study of the concrete structural elements reinforced with these bars, they are still not included in the international codes governing the use of FRP bars in concrete structures.This study aims to determine the suitability of using the computational formulas for the values of flexural capacity and deflection provided by some international codes such as CEB-FIP (2007), ACI 440.1R (2015) and the Syrian Arab Code Appendix No. 18 (2018) in concrete beams reinforced with BFRP bars, This is done by comparing the analytical and experimental values of the beams tested in this study, which also aims to determine the effect of the reinforcement ratio and the characteristic strength of concrete on the pressure on the flexural capacity and the deflection of these beams. The experimental work includes testing six simple supported reinforced beams subjected to two concentrated forces, four of these beams are reinforced with BFRP bars and two beams are reinforced with steel bars as reference beams. The results showed a good agreement between the analytical and experimental values of the cracking moment and the flexural capacity of the concrete beams reinforced with BFRP bars with differences that did not exceed 12%, while a significant difference appeared between the analytical and experimental values of the deflection at low loading levels, while the agreement was good at high loading levels with a reasonable conservative value of 17% in favor of safety according to the Syrian Arab Code Appendix No. 18 (2018(, Furthermore, the results showed the substantial influence of the reinforcement ratio compared to the impact of the characteristic strength of concrete on the pressure on the value of the deflection, and the role of the relatively low modulus of elasticity of BFRP bars in increasing the value of the deflection in the post-cracking stage.