The effect of non-toxic industrial wastes on the performance of fired earth bricks used in the rehabilitation of old buildings in Skikda, Algeria

This study examines the recycling of industrial waste into fired bricks for use in building rehabilitation, inspired by research that reports benefits to masonry quality and the environment. To this end, bricks from the old town of Skikda (Algeria), were analysed from a mineralogical, physical and mechanical point of view and compared with new bricks realized with clay from Mila (Algeria) mixed with different industrial wastes. Namely the clay mixtures were prepared with 10% sand and optimal amounts of sawdust (WS), steel filings (SF), fine marble powder (FMP) and very fine marble powder (VFMP), with substitution rates of 5%, 20%, 20% and 20%, respectively. Except for bricks with WS, which showed reduced resistance (-46.95%), the FMP, SF and VFMP bricks showed satisfactory mechanical performance with compressive strengths of 9.7, 9.8 and 11.1 MPa respectively. Moreover, the leaching analysis indicates that they are environmentally friendly.