Title: Shear Strength Reduction of Large-Scale Reinforced Concrete Beams with High-Strength Stirrups
Author(s): DongIk Shin, Muhammad Haroon, Changhyuk Kim, Byung-Soo Lee, and Jung-Yoon Lee
Publication: Structural Journal
Appears on pages(s): 161-172
Keywords: diagonal crack width; high-strength stirrups; large-scale reinforced concrete beams; shear strength; shear strength reduction; size effect
In recent years, several research studies on high-strength shear reinforcement higher than Grade 80 have been conducted. Use of high-strength shear reinforcement in large-scale structures can not only reduce the amount of shear reinforcement, but also improve the workability by creating wider stirrup spacing. However, members with high-strength shear reinforcement are more likely to cause compressive failure of concrete and wider cracks. In particular, when high-strength shear reinforcement is used for large-scale reinforced concrete beams, the size effect and the characteristics of high-strength steel bars may affect the shear behavior of largescale reinforced concrete beams. In this study, the shear behavior of large-scale reinforced concrete beams with high-strength stirrups was evaluated. The primary parameters of tests were the size of cross-section, stirrup yield strength, and spacing. Experimental results show that the stirrups in all specimens yielded before concrete web crushing. However, with increasing beam depth and amount of shear reinforcement, the margin between experimental and predicted shear strength decreased. In particular, the shear strength of specimens with high stirrup ratio was lower than the shear strength calculated by the ACI 318-14 code shear evaluation equation.