Effect of utilising ferrosilicon and recycled steel fibres on ultra-high-strength concrete containing recycled granite

This study investigates the utilisation of a combination of a few materials with various ratios, such as ferrosilicon (FS), recycled steel fibres (RSFs) resulting from waste tires and recycled granite (RG), to enhance the mechanical behaviour of ultra-high-strength concrete (UHSC). FS is a novel material that may be utilised as a partial replacement for the cement generated from the industrial waste product of FS alloy. The replacement ratios of FS used in this study are 10%, 20% and 30%. In addition to RSFs resulting from waste tires with ratios by volume of 0.5%, 1%, 1.5% and 2%, RG with replacement ratios of 25%, 50%, 75% and 100% from natural dolomite are used. The outcomes are represented in slump values, compressive strength, splitting tensile strength, flexural strength and modulus of elasticity. Microstructure analysis is also conducted to demonstrate the details of FS. Results reveal that the relatively better ratios to obtain high mechanical properties are 50% replacement of RG from natural dolomite and 20% replacement of FS from cement. The compressive strength of this mixture increases by about 11.11% over that of its reference mixture. The inclusion of RSFs obviates the brittle failure pattern of the tested cylinders, and a ductile failure occurs.