Shear capacity of cast-in headed anchors in steel fiber-reinforced concrete

This paper investigates the concrete breakout shear capacity of a single cast-in headed anchor embedded in steel fiber-reinforced concrete (SFRC). Experiments were carried out for anchors with a diameter of 30 mm, embedment depth of 240 mm, and edge distance of 150 mm. Fiber volume fractions of 0.33, 0.67, and 1.00% were examined. In addition to shear tests, four-point bending tests were carried out to evaluate the relationship between the material properties of SFRC and the shear capacity of anchors. The experimental results show that the current design formulas are valid for anchors in conventional plain concrete but not appropriate for the shear capacity of anchors in SFRC. Using the equivalent flexural strength ratio, a revised design equation is proposed to incorporate the effect of the steel fiber content on the concrete breakout shear capacity and provide reasonably similar safety for anchors in both un-reinforced and SFRC.