The production and storage of construction and demolition residues (CDR) consist in an important environmental issue because they represent more than 50 % of total solid waste that has been produced in large and medium-sized urban centers. However, as limestone is one of the major raw materials used in cement and hydrated lime products in the preparation of concrete and mortar, recycling this material can, in principle, provide a subproduct with potential to be applied to correct soil acidity. This study aimed to evaluate the use of recycled construction and demolition residues (RCD-R) as soil acidity corrective. The material was collected at a commercial recycling plant and consisted mainly of concrete and mortar (gray material), which was initially characterized by X-ray fluorescence and X-ray diffraction. The performance of gray RCD-R for soil pH correction was evaluated by the chemical properties of a medium-textured soil treated with this residue and the dry matter production of alfalfa (Medicago sativa cv. Crioula). Results suggest that the RCD-R used has promising characteristics to be applied as correction material of the soil pH, but at doses higher than 24 t ha-1.
recycling; limestone; cement; lime; agriculture
