Investigating the effectiveness of CFRP strengthening in improving the impact performance of RC members

Abstract

Rising global rail infrastructure expansion has increased accidents involving train derailments. Reinforced concrete (RC) elements require impact-resistance enhancement to prevent structural damage or failure. While extensive research has analyzed CFRP-strengthened concrete columns under dynamic loading, further understanding of CFRP's impact on RC members is needed. Considering dynamic factors, this study investigates CFRP-RC components' performance under asymmetric impact. Components wrapped in one, four, or six CFRP layers underwent high-energy asymmetric lateral impact testing to obtain deflection-time curves. Results showed that multiple CFRP layers significantly improved impact resistance by increasing plateau force, reducing maximum deflection to 42%, and shortening duration. Longitudinal-circumferential bonding conferred better reinforcement than other arrangements. However, multiple CFRP layers increased fracture susceptibility due to severe concrete damage. An equation was derived from dynamic equilibrium principles. Finite element modeling validated experimentally was used to simulate lateral impact. Impact force, deflection, and bending moment over time were compared. Impact resistance, flexural capacity, plastic deformation, and energy absorption were also examined. Internal force distribution and development were analyzed. A simplified calculation estimated maximum deflection. CFRP reinforcement methods' effects were examined. Results indicate CFRP elevates plateau impact force and average bending moment while significantly decreasing deflection and duration, greatly enhancing impact resistance and flexural bearing capacity.