Diagonal tension performance of concrete panels reinforced with hooked end steel fibers

The increase in strength of Steel Fiber Reinforced Concrete (SFRC) depends mainly on factors such as the dosage, aspect ratio and number of hooked ends of the fibers. Previous studies proposed models to estimate the flexural and shear strength of SFRC beams, but the shear behavior of SFRC panels has not been extensively studied. The study includes diagonal tension tests on concrete panels to assess the shear performance of SFRC. The experimental program comprises 19 square concrete panels having 600 mm side and 75 mm thickness, including three nominal dosages of steel fibers (20, 40 and 60 kg/m³) and three different number of hooked ends (1, 1.5 and 2). The study proposes models to predict the shear strength and deformation capacity, stiffness degradation and toughness of SFRC panels with different number of hooked ends when subjected to diagonal tension. The models include four characteristic limit states of diagonal cracking, maximum residual strength, code-based acceptable degradation, and maximum deformation.