The development of unfired clay building material using Brick Dust Waste and Mercia mudstone clay

This work reports the potential of using Brick Dust Waste (BDW) as a partial substitute for clay in the development of unfired clay building materials (brick, block and mortar). BDW is a waste material from the cutting of fired clay bricks. There are various reasons necessitating the cutting of bricks - corner bricks, construction of chimneys, and other uses needing bricks of various shapes and sizes. This results in the disposal of BDW as an environmental problem of concern. In order to investigate the clay replacement potential of BDW, four types of mixes were designed at varying BDW replacement levels - 5%, 10%, 15% and 20%. Ground Granulated Blastfurnace Slag, an industrial by-product from steel manufacture was activated using quick lime and the mixture was used to stabilise Mercia mudstone clay for unfired clay production. The 56 day compressive results using cylinder test specimens showed a significant strength gain (up to 2.1 N/mm2). Overall, the results suggest that it is possible to develop unfired clay building material using up to 20% BDW as partial substitutes for primary clay.