Recycle of ground granulated blast furnace slag and fly ash on eco-friendly brick production

Use of industrial by-products as waste-based materials in the building industry has recently received significant attention to develop eco-friendly building materials. This paper presents an experimental study on properties of bricks containing clay, ground granulated blast furnace slag (GGBS) and fly ash (FA) at 850, 950 and 1050 °C. Physical, mechanical, thermal tests and microstructural analyses were performed. Results show that an increase in firing temperature results in a decrease in porosity and an increase in the bulk density and compressive strength of bricks. Results also show that an increase in the FA content results in an increase in porosity and water absorption but a decrease in bulk density, compressive strength, and thermal conductivity of the bricks. GGBS content has much less significant influence on porosity, water absorption, bulk density and thermal conductivity of bricks, but an increase in GGBS content leads to a significant increase in compressive strength of bricks. Even the binary brick with 30% GGBS/10% FA exhibits nearly identical properties to the control brick. These highly promising findings suggest that replacement of clay with industrial by-products can provide eco-friendly bricks, the use of which would contribute toward reducing the environmental impact of abundant waste products and conserving non-renewable natural resources.