Martina Draganovska, Alena Sicakova

Selected parameters of concretes containing sludge from wet aggregates grading

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Abstract

The worldwide development of consumer society leads to an enormous increase of the amounts of waste and problems with its deposition. Therefore, the question how to utilize various wastes is still in the focus of research activities. The article represents a contribution to utilization of the sludge – waste produced during the process of wet aggregates grading as a substitute filler in cement composite – concrete. For the assessment of the properties of concretes with application of this secondary material as filler, recipes with 30, 60 and 100% replacement of natural fine aggregate were prepared and tested. For an objective determination of the results the reference sample containing only natural aggregates was prepared, as well. The consistency as a parameter of fresh concrete was evaluated during mixing. The following tests were performed after 28 and 90 days of setting and hardening: apparent density, compressive strength, capillarity and frost resistance. A formula with 30% replacement of fine aggregate reached the best values resulting from performed tests while the samples with 60 and 100% reached sufficient technical parameters despite worse achievements. The work has been shown that the tested sludge has a potential to act as filler in concrete. This seems to be one of the options of effective utilization of waste, which is not used commonly in present production of building materials.

Keywords: sludge; concrete; fine aggregate.