Compressive Strength and Density of Unfired Lightweight Coal Ash Brick

Coal-fired thermal power plant produces million tons of coal ash which constitute of fly ash and bottom ash annually throughout the world. They were by-product and significant to be developed as brick to substitute the existing widely used traditional material such as clay and sand brick which were produced from depleting and dwindling natural resources. In the present study, the coal ash from coal-fired thermal power plant was used as the main raw material for the fabrication of unfired lightweight brick. The blended binder comprising of Hydrated Lime (HL)-Ground Granulated Blastfurnace Slag (GGBS) and Portland Cement (PC)-GGBS were used to stabilize the coal ash in the fabrication process. Foam was used to reduce the weight of the brick. The compressive strength in accordance to BS EN 772-1 and ambient density in accordance to AS/NZS 4456.8 were evaluated on the brick samples. The results indicated that the coal ash brick incorporating PC-GGBS system achieved higher compressive strength compare to the HL-GGBS system. However, as the quantity of foam increase, the strength and density for both brick systems decreased.