Ikechukwu Ezegbunem^1,, Adewale Olutaiwo¹, Bola Mudasiru², Moshood Seriki³, Adebayo Olayemi⁴

This experimental study focused on exploring the potential utilization of rubbercrete for construction purposes by improving its workability and mechanical properties using agriculturally based supplementary cementing materials- rice husk ash, snail shell powder, pulverized cow bone and cow bone ash. Fine aggregate (sand) was partially replaced by waste crumb rubber at 0%, 5%, 10%, 15% and 20%. These agriculturally based supplementary cementing materials were included in the concrete mix as admixtures at 0%, 1% and 2% of Portland cement. Tests such as slump test; 28^th, 90^th and 120^th day compressive strength; as well as the 7^th and 28^th day flexural strength tests were conducted on fresh and hardened concrete to investigate the workability and structural performance of the modified concrete. Mix proportion of 1: 0.9: 2.8 and water-cement ratio of 0.35 for a characteristic strength of 40N/mm² was adopted for this study. The test results obtained revealed that the addition of snail shell powder, pulverized cow bone and cow bone ash improved the unsatisfactory compressive strength of rubbercrete significantly at 28days and at 2% inclusion.

agricultural wastes, crumb rubber, mechanical properties, rubbercrete, supplementary cementing materials