Investigation of using granite sludge waste and silica fume in clay bricks at different firing temperatures

Abstract

ABSTRACT A large amount of granite sludge waste (GSW) is produced during the granite quarry processing that has a negative impact on the environment. The main aim of this study to investigate the possibility of partial replacement of brick clay by GSW and silica fume (SF) due to the similarity of the mineralogical composition of GSW and clay. Five different series of clay to SF to GSW proportions were tried, which were (70:5:25), (70:10:20), (70:15:15), (70:20:10), (70:25:5) by weight. These bricks were mixed and molded in the dimensions of 50 x 50 x 50 mm3 and then fired at three different temperatures (700°C, 750°C and 800°C). The properties of green and fired bricks were studied as a function of waste percent. The vitrification parameters, such as compressive strength, water absorption, saturation coefficient, apparent porosity and bulk density, were determined and compared with ASTM standards. The results showed that the water absorption and compressive strength is very sensitive to the temperature changes than waste addition. It is possible to produce bricks with the highest compressive strength of 18.5 MPa at firing temperature 700°C using 70% clay, 25% SF and 5% granite sludge waste with water absorption of 18.2% and saturation coefficient 0.9 to meet the standard specification ASTM C216 grade for moderate weathering that are recommended for environmental and economic benefits.