EARLY AGE MECHANICAL PROPERTIES OF RUBBERISED CONCRETE MODIFIED WITH STEEL TYRE WIRE

The utilization of waste tyres in construction materials is one of the ways to solve the environmental problems caused by their disposal. This paper aims to investigate the strength behaviour of tyre wire rubberized concrete (TWRC) and develop models to predict its strengths characteristic with the aid of response surface methodology (RSM). In the manufacturing of TWRC mixtures, two variables were considered, which are the amount of crumb rubber replacement to fine aggregate by volume from 0 percent to 30 percent and tyre wire fibres from 0 to 2 percent by the weight of the cement used. The mix design was obtained from the design expert software using face centred central composite design, and three responses were considered. The strength properties investigated are compressive strength, flexural strength, and splitting tensile strength. Experimental results revealed that the addition of steel tyre wire fibres enhances the strength properties of the rubberised concrete due to high strain characteristics that enhance the bonding of the concrete, and thus producing a stronger model. The highest tensile value recorded was 3.10MPa with 0% crumb rubber and 2% steel tyre wire. Model equations were successfully established to predict the compressive strength, flexural strength, and splitting tensile strength of tyre wire rubberized concrete. The significance of the models developed was examined using Analysis of variance (ANOVA), and it was revealed that RSM models were in good agreement with experimental results.