Effect of partial replacement of crumb rubber in concrete made with Bida gravel

Abstract

ABSTRACT The availability of sand at cheap rates for use as fine aggregate in concrete production is ever becoming unfeasible and this, in addition to environmental sustainability, places a huge need to search for an alternative source of fine aggregate materials. Crumb rubber made from waste automobile tires, can be used to complement sand as fine aggregate in concrete production. This study seeks to investigate the effect of partially replacing fine aggregate with crumb rubber in concrete made with Bida natural stones. Crumb rubber gotten from waste automobile tires was used to replace fine aggregate in the concrete at 0%, 5%, 10%, 15%, 20% and 25%. The particle size distribution, workability and compressive strength of these concrete specimen were extensively studied. Curing was done for the period of 7, 14 and 21days. A mix ratio of 1: 1.65: 2.42 was used for cement content, fine aggregates and Bida natural stones, respectively, at a water to cement ratio of 0.45. Results from the workability test performed showed that a higher percentage replacement of crumb rubber gives a corresponding decrease in the workability of the concrete. In addition, the results obtained from each concrete mix for all cases of curing ages revealed that flexural and compressive strengths decrease with an increasing percentage replacement of crumb rubber in the concrete mix. The flexural strength of the concrete mix was observed to be 6.08N/mm2 at 5% crumb rubber replacement. While at 25% crumb rubber replacement, a flexural strength of 3.08N/mm2 was observed. Similarly, the compressive strength of the concrete mix at 5% crumb rubber replacement was noticed to be 20.88N/mm2 and was 11.89N/mm2 at 25% crumb rubber replacement. This implies that concrete made using crumb rubber as partial replacement for fine aggregate can be used for structural application such as in the construction of reinforced concrete slabs, beams, columns and foundations where high strength is not required.