Recycling of civil engineering solid waste to produce modular bricks

Resumo

The recycling and reuse of many industrial residues is nowadays one of the most important subjects in environmental preservation. Usually civil engineering solid waste (construction demolition waste or CDW) is composed of inert materials, but it is hazardous to the environment and is produced on a very large scale, mainly in developing countries. In the large cities of Brazil, this kind of residue corresponds to approximately 50 % of all urban solid waste, and in most of them it is dumped in improper places. In this work, the reuse of solid wastes from the civil engineering industry to produce bricks was studied. The assorted material was crushed and sieved (£ 4.8 mm). Lime used to prepare mortar was used as a binding agent. Lime, crushed residue and water were mixed in different combinations and pressed using a uniaxial hydraulic press. The probes (~ 60mm x 30mm (f)) with up to 21days curing were submitted to mechanical compression tests and to three points flexural strength test (60mm x 20mm x ~7mm prismatic probes). Water absorption and apparent porosity and density were also determined. The results show that it is possible to produce low-cost bricks with excellent physical properties using CDW.