Waste tyre fibres : investigating the potential use in concrete

Abstract

Steel tyre fibres are one of the products derived from the process of shredding waste tyres. Contrary to other tyre derived products, no specific niche has been yet found where this material can be utilized feasibly on an industrial scale. As a result, this material is still considered as a waste product. This investigation aims to utilise waste tyre fibres as fibre reinforcement in concrete. This is carried out by characterizing the quality of the fibres obtained from a local tyre recycling plant and quantifying the mechanical properties of concrete reinforced with these fibres. For this purpose thirteen mixes, one plain control mix and twelve fibre reinforced mixes were prepared. Three of the mixes were reinforced with shredded tyre fibres, the rest with other industrial fibres available on the market. These were purposely chosen with particular aspect ratios and geometric shapes. These were added to fresh concrete at three different volume fractions – 1, 1.5 and 2%. Compressive and flexural tensile strength tests were carried out on different samples from each mix, at 7 and 28 days to determine the performance of the concrete in the hardened state. The results obtained indicate that to a limited extent shredded tyre fibres can be used as concrete fibre reinforcement. Flexural tests on shredded tyre fibre reinforced concrete show improved performance over certain industrial fibres available on the market.