Mechanical model for the shear strength of steel fibers reinforced concrete beams (SFRC) without stirrups

Despite the numerous studies made showing that the addition of steel fibres to concrete enhances the shear strength of RC beams, current design formulations are still empirical and present large scatter in front of the test results. In this paper, the previously developed Multi-Action Shear Model is extended to SFRC beams without stirrups, adopting an analytical formulation to evaluate the residual tensile stress of SFRC and incorporating the effects of the crack bridging capacity of SFRC in the shear resisted trough the different shear-transfer mechanisms. The proposed model predicts the tests results included in a recently published database with 448 shear tests with less scatter than any of the existing models.
The financial support provided by the University of Messina (Italy), through the scholarship granted for a two-months research and teaching stage of the first author, is acknowledged. This work is part of the Research Projects BIA2015-64672-C4-1-R, funded by the Spanish Ministry of Economy and competitiveness, and RTI2018-097314-B-C21, funded by the Spanish Ministry of Science and Innovation.
Postprint (published version)