Flexural Performance of Concrete Beams Reinforced with Basalt Fiber Reinforced Polymers (BFRP) Bars

Abstract

This research studies the flexural behavior of concrete beams that are reinforced longitudinally with the newly discovered Basalt Fiber Reinforced Polymers (BFRP) bars. The aim is to examine the suitability of using BFRP bars in flexure as compared to Carbon FRP bars and to validate its compatibility with the recommendations and guidelines of the current ACI440 Code. The effect of different design parameters such as BFRP reinforcement ratio, reinforcement axial stiffness and concrete compressive strength are studied. In addition, this research sheds the light on evaluating the bond-dependent coefficient (kb) value for this new type of FRP composites. Four-point loading tests were performed on a total of 14 beams (180 mm × 230 mm × 2200 mm) to achieve the objectives of this research. The loads vs mid-span deflections, cracks behavior and widths, ultimate capacities and failure modes of all 14 beams are recorded and discussed. Results confirmed that BFRP bars could be a valuable alternative to steel and CFRP bars and can be used in similar applications in the construction industry. The flexural behavior of BFRP-reinforced beams compared well with the ACI440.1R guidelines. The experimental moment capacities well-matched their theoretical counterparts using the code equations. For all the beams, the calculated bond dependent coefficients (kb) values were found to be lower than the values recommended by the ACI440.1R code which clearly indicates a strong bond between the FRP bars and concrete. The test results can be utilized as a control for a long-term durability study on the performance of BFRP bars under the harsh environment.