Tensile cracking constitutive model of Steel Fiber Reinforced Concrete (SFRC)

This paper deals with the tensile cracking constitutive relationship of Steel Fiber Reinforced Concrete (SFRC) considering the effects of steel fiber content and fiber length. To investigate the effect of fiber content and length, notched 3-point bending tests were executed, where the fiber content was varied from 0.87% to 2.61%. From the bending tests, it was found that the flexural tensile strength of SFRC linearly increases with increasing fiber content and the rule of mixture can be applied to SFRC. Additionally, an inverse analysis was performed to determine the tensile cracking constitutive model of SFRC and a tri-linear tensile softening model is also suggested. The suggested model successfully represents the increase of the stress-constant bridging zone and the decrease of the stress-resisting zone with increasing fiber content. The proposed constitutive models including both long and short fibers for various fiber contents are simple and can be effectively applied to the numerical analysis of SFRC, which can consider steel fiber effects.