ULTRA-DUCTILE FIBER–REINFORCED POLYMER–CONCRETE HYBRIDS FOR IMPACT-RESISTANT INFRASTRUCTURE

Abstract

Modern infrastructure increasingly faces the risk of high-velocity impacts from accidental collisions, debris strikes, and blast-induced projectiles, necessitating the development of structural systems with superior toughness and damage tolerance. This study presents an ultra-ductile hybrid composite integrating Fiber–Reinforced Polymer (FRP) laminates with engineered fiber-reinforced concrete to improve impact resistance and post-damage performance. The hybrid system utilizes multi-directional FRP sheets combined with micro- and macro-scale fibers within a high-performance cementitious matrix to enhance crack-bridging capacity, energy absorption, and residual strength. A comprehensive methodology incorporating material characterization, structural-scale specimen fabrication, dropweight impact testing, and numerical modeling was employed to evaluate hybrid behavior under varying impact intensities. Experimental results revealed substantial improvements in peak impact force capacity, reduced crack widths, greater ductility, and enhanced ability to sustain repeated impacts without catastrophic failure. Finite element simulations corroborated the experimental findings, demonstrating efficient stress redistribution, delayed spalling, and lower strain localization within FRP-integrated regions. The study highlights the synergistic interaction between FRP confinement and ductile concrete matrices, enabling superior impact mitigation compared to conventional concrete. These findings offer promising implications for designing protective infrastructure such as bridge piers, crash barriers, retaining walls, and industrial facilities exposed to impact hazards. The proposed hybrid FRP–concrete system provides a sustainable, lightweight, and highly resilient solution for next-generation impact-resistant infrastructure.