Investigation on bonding behavior of basalt fiber reinforced polymer (BFRP) sheet reinforced concrete beam

Although basalt fiber reinforced polymer (BFRP) sheet offers promising benefits including environmental friendliness and excellent mechanical performance in concrete reinforcement, its full potential is still hindered by the lack of understanding about their bonding mechanism. Therefore, the comprehensive investigation of the bonding behavior of BFRP sheet reinforced concrete is necessary. This work aims to address the research gap between the analytical design and industrial application of BFRP sheet reinforced concrete due to the complicated bonding behavior. Analytical method, experimental measurement, and numerical simulation are employed to comprehensively investigate the bonding behavior of BFRP sheet reinforced concrete. According to the mechanical model and assumptions of the reinforcement, analytical solutions for interfacial stress and strain are derived. In addition, four-point bending test are conducted on specimens, and multi-view digital image correlation (DIC) technique is used to analyze the deformation on concrete part and BFRP sheet simultaneously. Based on analytical and experimental results, finite element model (FEM) is applied to simulate mechanical behavior of BFRP sheet reinforced concrete beam, and parametric analysis is further conducted. Results reveals that the maximum interfacial stress appears at the end of bonding region so that BFRP debonding at the end is the main failure mode. The strain distribution of BFRP sheet obtained by multi-view DIC indicates that there is an effective bonding region. Besides, strain can be used as a variable to validate numerical model by analytical and experimental results. The validated numerical simulation could be conducted for the internal response study and application design of BFRP sheet reinforcement.