Utilization Potential of Pulverized Construction Demolition Waste as Fine Aggregate in the
Production of Concrete
1Oluremi J. R. and 2* Olabode O. I.
1,2 Department of Civil Engineering, Ladoke Akintola University of Technology, Ogbomoso, Nigeria
DOI: 10.36108/laujoces/5202.51.0161
Abstract
Concrete is the most widely used construction material due to its high compressive strength, durability, low cost, and versatility; however, the depletion of the natural rock materials commonly used as aggregates is of concern. This study therefore explores the potential of using Construction and Demolition Waste (CDW) as a partial replacement for fine aggregates in concrete as a mean of addressing environmental concerns linked to CDW disposal. Sieve analysis, aggregate crushing and impact values and water absorption were carried out on the aggregates used. Concrete mixes of M15 (1:2:4) and M10 (1:3:6) were prepared with CDW replacing fine aggregates at 5, 10, 15, 20, 25 and 30% levels and were assessed using standard tests such as slump, compressive, and flexural strength tests. Natural fine aggregates and CDW had fineness moduli of 4.17 and 4.10%, respectively classifying both as coarse sand. The slump values increased with increasing CDW content for both mixes. The highest compressive strength of 29.99 N/mm² and 30.10 N/mm² were observed at 5% CDW replacement after 28 days for the M10 and M15 mix, respectively, compared to 29.08 N/mm² for the control which showed strength gains at early curing ages. The highest flexural strength was 6.83 N/mm² for the control mix and 6.77 N/mm² at 5% CDW replacement. However, increasing CDW content beyond 5% resulted in decreased compressive and flexural strengths. With 5% CDW replacement, the results of both compressive and flexural strengths are within permissible standard and it is therefore recommended for use in concrete production.
Keywords: Concrete, Construction and demolition waste (CDW), Compressive strength, Flexural strength, Fine aggregate, Partial replacement