Assessing the feasibility of making bio cement from rice husk ash and eggshell powder

Abstract

Despite its fundamental role in infrastructure development and economic growth, global cement production, accounting for approximately 7% of total anthropogenic CO2 emissions, remains a significant environmental concern. In studies aiming to develop ecofriendly cement, eggshell powder (ESP) has emerged as a promising alternative to limestone basing on similarity in their chemical composition. However, current research has insufficiently expounded the potential solutions to address the limited later strength development of ESP in mortar and concrete. This research focused on assessing rice husk’s capability due to its high silica content to enhance later strength in mortar other than use of slag. This research was mainly experimental. The process involved mixing ESP and RHA in varying proportions contributing up to 20% together with 80% ordinary Portland cement to form five different test samples and one control sample. The blended cement samples were characterized to determine their physical properties such as specific gravity, fineness and density. In addition, the cement samples were used to make mortar which was also tested for density and compression strength during 28 days of curing. Findings indicated that the blended cement samples had lower values for density and specific gravity compared to OPC. This research also revealed that equal proportioned ESP and RHA in the 20% replacement produced mortar with a compression strength higher than that produced by mortar made of OPC. However, the cost per square of blended cement mortar was higher than that of OPC mortar. This was mainly due to absence of predetermined methods of processing eggshell powder and rice husk ash thus leading to an increase in their cost of production.