Re-use of construction and demolition residues and industrial wastes for the elaboration or recycled eco-efficient concretes

Résumé

Production of residues from industries and construction and demolition sectors has increased during last years. The total amount of debris produced according to different estimations reaches values close to 42 million tonnes yr�1. Much of this waste has been thrown to landfill, without considering its potential for reuse, recycling or valuation. The aim of this research is to describe some of the physical and mechanical properties of different laboratory-mixed concretes, using various proportions of additional materials recovered from industrial waste and demolition rubble. The added materials are included either as admixtures (forestry residues, cork dust, steel fibre) or in partial substitution of natural aggregates (wire from electrical residues, tyre rubber, white ceramic, sanitary porcelain or shale). The laboratory tests have followed the standard EN protocols. Assay results were variable according to the nature of the material added to the mix: organic materials and shale, despite the steel fibre reinforcement, reduce the compression strength, but are suitable for the manufacture of lightweight concrete for agricultural pavements, with certain flexion resistance and a relatively good behaviour to impact. The substitution of natural aggregates with ceramic and porcelain wastes produces a significant increase in compression resistance, making them suitable for the manufacture of concrete with characteristic resistances above 40 MPa, which can be used both for structures or other agricultural elements: separators, feeders, slat floors. As a conclusion can be stated the possibility of reuse these wastes for the production of structural or non-structural concrete, with different applications in agricultural engineering.