A Review on the Behaviour of Headed Reinforcement in Steel Fiber Reinforced Concrete Beam–Column Connection

Abstract

Beam–column connections are critical regions in reinforced concrete framed structures because they transfer axial forces, bending moments, and shear forces between structural members. Their performance becomes particularly important under seismic loading, where inadequate anchorage, reinforcement congestion, bond deterioration, and diagonal joint cracking may cause brittle failure. This review examines the development and structural performance of headed reinforcement used in combination with Steel Fiber Reinforced Concrete (SFRC) in beam–column connections. Headed reinforcement transfers bar forces through mechanical bearing at the enlarged head, thereby reducing development-length requirements, reinforcement congestion, and bar slippage. Steel fibers act as randomly distributed crack-bridging reinforcement that improves tensile resistance, toughness, ductility, crack control, and post-cracking load capacity. Previous experimental, analytical, and numerical studies indicate that headed bars can provide anchorage performance comparable or superior to conventional hooks, provided adequate embedment, concrete cover, head dimensions, and confinement are maintained. Research on SFRC joints shows improvements in joint shear strength, stiffness retention, ductility, crack distribution, and energy dissipation. The combined system provides complementary benefits by strengthening the concrete surrounding the mechanical anchorage while ensuring effective force transfer. However, further research is required on reversed cyclic loading, long-term durability, full-scale connections, higher fiber contents, and standardised design provisions.