Production of sustainable clay bricks using waste fly ash: Mechanical and durability properties

Abstract

Burnt clay brick is one of the ancient building material. The use of waste materials in bricks can lessen the consumption of clay material and reduce the environmental burden due to accumulation of waste materials. Furthermore, addition of recycled materials can decrease the high carbon footprint. In the current study, bricks were manufactured using fly ash (by-product of coal) and conventional earthen materials. Fly ash was acquired from the coal power plant. Manufacturing of brick specimens was done in a local brick industry. The main variable in this study was the percentage of fly ash (i.e. 0–25% of clay). Results indicate that the compressive strength of bricks incorporating fly ash was lower as compared to that of clay bricks without fly ash. However, compressive strength of bricks incorporating up to 20% of fly ash satisfied the minimum requirements of the Pakistan Building Code. Reduction in weight was also observed in the fly ash bricks which would lead to overall weight reduction of the structures. Furthermore, less efflorescence was observed in bricks incorporating fly ash. Therefore, it can be concluded that clay bricks incorporating fly ash can be helpful in producing more sustainable bricks leading to economical solution.