Reuse of pulverized fired clay brick wastes as cement substitute in mortar for sustainable construction

Recently, there has been an increase on the use of waste materials for development of new materials for construction. This is due to the need for sustainable development which emphasizes on waste reduction, reduction of greenhouse gases (GHG), greener clean environment and conservation of raw resources. This study examines the appropriateness of clay brick waste in powder form as a suitable material for partial substitute of cement in mortar. The clay bricks were obtained as generated waste materials from a brick producing factory in Lagos metropolis and then subjected to grinding. Tests which include; specific gravity, particle size distribution, x-ray fluorescence and scanning electron microscopy were carried out on the pulverized clay brick material (CBP). Further, it is used to partially replace cement in mortar at replacement percentage of 0, 5, 10, 20, 25, 30, 40 and 50% using a mix ratio of 1: 2.75 at 0.45 water-cement ratio. Compressive strength and strength activity index tests were carried out on the cube specimens after days of curing. The obtained results clearly indicate that the pulverized clay brick is an amorphous material and contains similar chemical oxide compounds of a pozzolana. Furthermore, it was observed that the compressive strength of the mortar was further improve at an optimum value of 20% cement replacement with clay brick powder compared to the control mortar. Therefore it implies that generated clay brick wastes can be pulverized and used as pozzolanic admixture in mortar production instead of discriminate dumping in landfill. (paper)