Flexural strength of concrete beam produced with scrap rubber tyres as partial replacement for coarse aggregates

Abstract

The quantities of waste generation in Nigeria have increased significantly; posing greater risk to public health owing to indecent manner of disposal. Some solid wastes had been recycled; however, studies on scrap rubber tyre have not been fully exhausted. This research therefore investigated the flexural behaviour of concrete produced using scrap rubber tyre as partial replacement of coarse aggregate. Scrap Rubber Tyres (SRT) were chopped into smaller sizes; with 19 mm maximum size and used to partially replace coarse aggregate within 0 to 12% at 3% interval. The constituents were batched by weight. 45 concrete beams of grade 20 were cast and cured for 7, 28 and 90 days. Flexural strength behaviour of the specimens was tested; and the 0% SRT concrete serves as control. Data were analysed using Analysis of Variance at 5% Significance level. The slump and compacting factor of the fresh concrete ranged from 29-100 mm and 89-99%, respectively. The flexural strength of the rubberized concrete at 28 days were 21.3, 14.0, 13.2, 12.2, and 13.3 N/mm2. Rubberized concrete at 3% partial replacement can be useful for light weight structural members. The scrap rubber tyres possess significant potentials which could advance its utilization under improve technology.