How do steel fibers improve the shear capacity of reinforced concrete beams without stirrups?

I’ve recently published a review paper in the journal Composites Part B: Engineering titled “How do steel fibers improve the shear capacity of reinforced concrete beams without stirrups?”.

The paper addresses the different shear-carrying mechanisms, and the effect of adding steel fibers to a concrete mix on these shear-carrying mechanisms in specimens with steel tension reinforcement. This review paper is the result of my Poligrant 2017-2018, continued as a Poligrant 2018-2019. While originally I started the research to find a way to extend to Critical Shear Displacement Theory with an extra term that takes the contribution of the fibers into account, reading on the topic and understanding the mechanics further led me to the insight that the simple solution of adding an extra term is insufficient. This paper shows how all shear-carrying mechanisms are influenced by the presence of fibers.

The abstract is:
Even though the structural behavior steel fiber reinforced concrete (SFRC) has been extensively researched, structural applications are still limited. One barrier to its implementation is the lack of mechanical models that describe the behaviour of SFRC members failing in shear. This paper reviews the effect of steel fibers on the different mechanisms of shear transfer and combines the observations from the literature regarding the parameters that affect the shear capacity of SFRC. Additionally, a selection of currently available expressions for the shear capacity of SFRC is presented. This paper reviews the current state-of-the-art on the shear capacity of SFRC elements without shear reinforcement, shows the lacks in our current understanding on the shear behaviour of SFRC elements without shear reinforcement, and outlines the steps necessary to address these lacks. The presented work aims to be a framework for (experimental) efforts addressing the shear capacity of SFRC members without shear reinforcement.

You can access the article here.