Bond constitutive relationship for steel fiber reinforced self-compacting concrete

Steel fiber reinforced self-compacting concrete (SFRSCC) is a relatively new composite material
which congregates the benefits of the SCC technology with the profits derived from the addition of fiber
to a brittle cementitious matrix. Steel fibers improve many of the mechanical properties of self-compacting
concrete (SCC) elements including tensile strength, ductility, toughness, energy absorption capacity, and fracture
toughness. This paper investigates the bond characteristics between steel fiber and SCC based on the
available experimental results. An analytical steel fiber pullout model proposed by Dubey (1999) is modified
by considering the different mechanical properties of SCC and different fiber types (smooth, hooked) and inclination.
In order to take into account the effect of the fiber inclination in the pullout model, apparent shear
strengths (τ(app)) and slip coefficient (β) are incorporated to express the variation of pullout peak load and the
augmentation of peak slip as the inclination angle increases. These variables are expressed as functions of the
inclination angle (ϕ).