Flexural behavior of full-scale circular concrete members reinforced with basalt FRP bars and spirals: Tests and theoretical studies

This paper reports on the experimental results of flexural tests on full-scale circular reinforced concrete members with a total length of 6000 mm and diameter of 500 mm reinforced with Basalt Fiber-Reinforced-Polymer (BFRP) reinforcement, followed by an intensive analytical study and finite-element analysis. The main investigated parameters were the ratio and type of longitudinal reinforcement. A steel-reinforced concrete specimen was fabricated as a reference. Test results show that the deformability of the tested circular BFRP-RC members significantly exceeded the limitations in North American codes. Moreover, the nominal flexural strength of one BFRP-RC specimen was almost two times that of its steel-reinforced counterpart with the same reinforcement ratio. The analytical model presented herein using a layer-by-layer analysis was capable of predicting the flexural strength of the circular BFRP-RC members. In addition, a non-iterative analysis method including simple design equations are presented. This method accurately and simply predicted the flexural capacity and can be considered a simple and more straightforward method for practicing engineers. In addition, the finite-element model developed predicted the response of the tested specimens with a reasonable degree of accuracy and was used to extend the range of the investigated parameters.