Structural Performance of High-Strength Self-Compacting Lightweight Concrete Beams Considering the Shear Contribution of Steel Fibers

This study aims to evaluate the feasibility of replacing the minimum shear reinforcement in high-strength self-compacting lightweight concrete (HSLC) beams with hooked-end steel fibers at a volume fraction of 0.75 vol.% and to quantitatively assess the contribution of steel fibers to the shear capacity of the beams. Six HSLC beam specimens were tested to determine load-bearing behavior and failure modes under different reinforcement schemes, including beams without steel fibers or stirrups, beams reinforced with either steel fibers or stirrups, and beams incorporating both steel fibers and stirrups. The experimental results indicate that replacing the minimum shear reinforcement with 0.75 vol.% hooked-end steel fibers increased the flexural capacity, ultimate deflection, and energy absorption capacity by 2.5%, 7.8%, and 16.1%, respectively, thereby confirming the feasibility of using hooked-end steel fibers as a substitute for minimum shear reinforcement. The fiber shear capacity, calculated from experimental data, was compared with various prediction equations. Models containing the fiber factor demonstrated better agreement with test results, showing a minimum difference of 10.1%.