Evaluation of the Structural Behaviour of Ordinary Portland Cement - Rice Husk Ash Concrete by

Student: Samuel John Edet (Project, 2025)
Department of Civil Engineering
Cross Rivers University of Technology, Calabar, Cross Rivers State


Abstract

Cement is a crucial material for making concrete, acting as a binder for solid components, but it is also a major contributor to carbon dioxide (CO2) emissions, accounting for up to 10% of global CO2 output. This makes the sustainability of concrete a significant concern. The production of concrete consumes large amounts of natural resources like sand, gravel, water, coal, and crushed rock, which can harm the environment through mining. However, energy and cost efficiency can be improved by reducing the amount of clinker used and substituting it with partial cement replacements or pozzolans that require less heat during production and emit lower levels of CO2. This study examines the use of Rice Husk Ash (RHA), an agro-waste byproduct, as a partial replacement for Portland cement (OPC). Experiments were conducted by partially replacing OPC in concrete mixes with RHA at varying levels (2.5%, 5%, 10%, 15%, and 20%) using a water-to-cement ratio of 0.50. These mixes were compared to a control sample without RHA. The results demonstrated strong early compressive strength, with the 2.5% and 5% RHA mixtures outperforming the control. The findings suggest that RHA could be a promising pozzolan, potentially improving both the sustainability and economic viability of concrete.

Keywords
evaluation structural behaviour ordinary portland cement concrete flexural strength split tensile strength compressive strength