Shear strengthening and rehabilitation of high-strength continuous RC beams with BFRP: A combined experimental and numerical study

This study explores the use of Basalt Fiber-Reinforced Polymer (BFRP) as a retrofit and strengthening solution to improve the shear performance and durability of high-strength reinforced concrete (RC) beams. In total, seven full-scale RC beams with two-span layouts, each measuring 2 m in length, were evaluated under different test setups. One beam was left unstrengthened to act as a control, while the remaining specimens were either retrofitted or upgraded using a variety of BFRP configurations, including sheets and ropes of varying densities. Before the BFRP application, three specimens were preloaded to 70 % of their ultimate strength to mimic pre-existing structural deterioration. Post-strengthening, the beams demonstrated significant improvements in shear capacity. Specifically, externally strengthened beams showed load capacity increases ranging between 17 % and 37.4 %, whereas those that underwent rehabilitation experienced gains between 5.7 % and 19.4 %. The findings confirm the effectiveness of BFRP for both structural repair and enhancement, highlighting its role in restoring or boosting the load-bearing ability of RC members. Furthermore, the outcomes were consistent with finite element analysis and closely followed the ACI 440.2R-08 guidelines, validating the experimental results. Overall, the research identifies BFRP materials as a sustainable and efficient method for structural strengthening and rehabilitation.