Experimental study on shear mechanical property of SFRCC with high steel fiber content

Shear behavior is a critical indicator of mechanical performance in concrete structural design. Although many research studies have focused on the shear performance of steel fiber-reinforced cementitious composite (SFRCC) within a relatively low fiber content (0-2 %) and developed corresponding shear strength prediction models, the effects of high steel fiber content have not been evaluated. Also, the coupling effect of matrix strength and steel fibers has not been considered. The applicability and predictive accuracy of such models for various steel fiber contents is, thus, questionable. In order to address these research gaps, the shear performance of SFRCC incorporating a high steel fiber content has been evaluated in this study. As the steel fiber content increases from 0 % to 10 %, the shear strength increases by a factor of 1.5-5.2, peak shear displacement multiplies by 2.9-8.3, and the peak pre-yield shear ductility enhances by a factor of 8.0-50.6. The quantitative assessment of existing shear strength prediction models was also conducted. It was found that factors influencing the shear strength of SFRCC extend beyond steel fiber content alone; matrix shear strength is also a critical influencing factor. Also, the effects of matrix shear strength and steel fiber content on SFRCC shear strength are interdependent. Thus, considering the coupled effect between matrix shear strength and steel fiber content, two shear strength prediction models with respective accuracies of 90.1 % and 71.2 % are proposed, which exhibit greater accuracy and reliability. The shear performance of SFRCC materials for different steel fiber contents and corresponding shear strength prediction models offer valuable reference and support for the application of SFRCC in structural engineering.