Behavior of Steel Fibre Reinforced Concrete According to the Shear-Friction Theory

Abstract

The amount of traditional reinforcement of steel bars in reinforced concrete can be reduced by adding fibres. This type of concrete, with steel fibres, is called steel fibre reinforced concrete (SFRC) and allows the total or partial elimination of the reinforcement against shear stress. Different regulations consider the structural capacity of steel fibres, for any type of stress, depending on values of residual flexural strengths. It does not seem appropriate to use these residual strengths to design the SFRC on shear stresses. So, the present research was developed and two SFRC were analysed, loaded under shear, comparing them with their theoretical study in relation to the shear-friction theory. The steel fibres bridges the crack the fissures preventing them from developing freely, increasing the friction between the faces of the crack. The experimental part developed direct cutting tests type "push-off" com-plemented with digital image correlation technique to obtain the variations of sliding and crack opening. It can be indicated that, in the post-cracking stages, the fibres are the ones that govern the behaviour of the material and that the results of the analytical model are very similar to those found in the experimental campaign for slips of up to just over 4 mm.