Evaluation of pozzolanic activity in mortars containing granite residues
João de Farias Filho, Gelmires A. Neves, Heber S. Ferreira, José Wallace B. do Nascimento, Romualdo R. Menezes and Luciana de Figueiredo L. Lucena

Although the ornamental granite mining and processing industry has been considered to be one of the most promising in the minerals sector, it can cause serious environmental problems. Such problems mostly occur because companies in this industry generate large amounts of waste, which are released into the environment without pretreatment. These wastes are made up of silica, particles of granite and crushed lime. This work has the main objective of evaluating the existing pozzolanic activity in alternative mortars, which were obtained by partially substituting the lime (Ca(OH2)) with industrial residues of granite. Some assays of physical and mineralogical characterization have been carried out, such as: particle-size-distribution analysis; chemical analysis; and X-ray diffraction. For the technological tests, test bodies in cylindrical form were moulded, with dimensions of 50 mm x 10 mm, with mix design 1:3, incorporated with 20%, 35% and 50% residues by weight, substituting part of the whitewash, with a water/cement factor of 0.48. The test bodies were cured for periods of seven, 28 and 60 days. Pozzolanic activity was analysed by simple compressive strength (RCS). Analysis of the results found that the alternative mortars that incorporated 30, 35 and 50% granite residues increase mechanical strength by between 13 and 64%. These results indicate that the addition of granite residues speeds up the hydration of calcium hydroxide, due to the pozzolanic activity.

Key words: granite residues, mortars, pozzolanic activity, recycling

Land Contamination & Reclamation, 18 (4), 389-391 (2011)

DOI 10.2462/09670513.1019

© EPP Publications Ltd 2011

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Article code 1019