Self-compacting concrete strengthening efficiency investigation by using recycled steel waste as fibres

Steel recycling saves energy and time, and is more environmentally friendly. It can help rid the environment of huge amounts of scrap vehicles and huge structures, as well as reducing the mining operations that destroy the natural environment. In this investigation, the steel scrap effect on the mechanical properties of concrete was investigated, in addition to investigating the variation in mechanical properties with increased concrete age. Three concrete mixes were studied: one without steel waste as a control, one with 1% steel waste by volume of concrete, and one with 1.5% steel waste by volume of concrete. The results show that adding waste steel to the concrete improved the compressive strength as well as the tensile strength, where a mixture which contains 1% of steel waste had an increase in strength of up to 12% and 23% by day 28 for compressive strength, and tensile strength sequentially in comparison to the reference mix. Furthermore, the results show that there was a significant increase in splitting tensile strength, at 29% on day 28 for a mix of 1.5% steel waste as compared to the reference concrete mix. The best improvement in compressive strength over time was obtained when using 1% steel waste. The best improvement in tensile strength over time was obtained when using 1.5% of steel waste. In both cases, the amount of the improvement was better than the models without steel waste, which gives us confidence in giving recommendations for conducting more in-depth studies to achieve the maximum advantage.