Toughness and Stiffness of Fibre Reinforced Concrete in Terms of Shear Capacity

•Presence of fibres regardless the type generally develops the strength of concrete mixes in shear.•Shear toughness, indicated by toughness Index I5, is generally increased at concrete mixes containing fibres, regardless the type of fibres.•Shear toughness related to cracks perpendicular to load has higher values to shear toughness related to cracks parallel to load.•High temperatures, i.e., 700 °C, decreases shear toughness of concrete mixes.•Mixes with cocktail fibres suffered less than other mixes, in terms of shear toughness.•Shear stiffness is significantly decreased by increasing temperatures.