Fiber-reinforced concrete with low content of recycled steel fiber: Shear behaviour

•The shear properties of SFRC with fibers recycled from scrap tires were studied.•Fresh and hardened concrete properties are reported.•Experimental direct shear tests were carried out on specimens varying the type of fibre reinforcements.•An analytical analysis was done aims to evaluate the shear stress versus displacement curves.•The obtained results confirm promising applications of concrete reinforced with RSF. The sustainability of construction materials is a mandatory issue that started to be strongly felt in view of a global perspective of environmental protection. Wasted materials often may find a new lifecycle if well re-engineered, even in structural applications. In this field short steel fibers obtained from used tyres at the end of their life may find promising applications within a concrete matrix. In the present research the mechanical properties of recycled steel fiber-reinforced concrete in terms of workability, compressive and tensile strength, toughness and shear behaviour are analysed and compared with those of industrial steel fiber-reinforced concrete and ordinary Portland concrete. An experimental campaign is illustrated, and an extensive comparison in terms of shear strength has been studied considering different experimental works available in scientific literature. Moreover, a theoretical analysis aimed at evaluating and comparing the shear modulus of the analysed concrete type was carried out. The results obtained through this study show a satisfactory behaviour of the concrete reinforced with recycled steel fibers compared with industrial new steel fibers reinforced concrete, both in terms of toughness and shear behaviour.