Physical and mechanical properties of concrete with added dry sludge from a sewage treatment plant

One of the main objectives of this study was to evaluate an alternative final destination for the growing production of sludge from sewage treatment plants. At present, a significant quantity of dry sludge is obtained in Catalonia. That is why this paper examines the possibility of adding this waste product to plain concrete with Portland cement. Taking into account the authors' previous work, this study focused on making specimens of concrete containing different percentages of sludge from a sewage treatment plant, studying both their physical properties (density, porosity, and absorption capacity) and their mechanical properties (compressive strength, flexural strength, and elastic modulus) over time. The results confirmed that up to 10% of treatment plant sludge can be added to concrete for use in certain very specific applications. (C) 2004 Elsevier Ltd. All rights reserved.