Eco-friendly fired clay bricks incorporated with porcelain ceramic sludge

Abstract

Due to the limited natural clay resources, a shift to alternative resources for brick clay is a challenge in the construction industry. A possibility of brick clay replacement with ceramic sludge in manufacturing of eco-friendly bricks is investigated by evaluating strength, durability and thermal performances of bricks. For this purpose, clay bricks were manufactured by blending ceramic sludge in five mix proportions: 0%, 20%, 40%, 50% and 60% by weight. Raw materials were characterised by bulk density, specific gravity, sieve analysis, X-Ray Fluoresce (XRF) and X-Ray Diffraction (XRD) while the mixtures were characterised by Atterberg’s limits. The bricks were characterised by dry weight, micro-structure, strength property (compressive strength), durability properties (i.e. water absorption, initial rate of sorption, acid and alkaline resistance, efflorescence), thermal performance and XRD patterns. Reduced dry weight was found with increasing ceramic sludge contents, promising a light weight clay brick. With 40% ceramic sludge, the optimum compressive strength was found to be 2.9 N/mm2, indicating 32% strength improvement, comparing to the conventional brick. At 40% ceramic sludge, water absorption was 20.6%, satisfying the requirement for moderate weathering resistance. The acid and alkaline resistances of bricks increase with increasing ceramic sludge content, indicating that ceramic sludge contributes to increase durability performance of the brick. In addition, the bricks with 40% clay replacement yielded better thermal performances. At 12:30, when the day time temperature is expected to be the highest, 10.1 °C temperature difference was observed for the 40% ceramic sludge blended brick, whereas 4.2 °C difference was observed for the conventional brick. An eco-friendly brick with improved strength, durability and thermal properties can be achieved by 40% replacement of brick clay with ceramic sludge.