Mechanical properties of concrete produced with a composite of water treatment sludge and sawdust

• Published in: Construction & building materials 2011-06, Vol.25 (6), p.2793-2798
• Main Authors: Sales, Almir, de Souza, Francis Rodrigues, Almeida, Fernando do Couto Rosa
• Format: Article
• Language: English
• Subjects: Analysis; Compressive strength; Concrete; Concretes; Construction materials; Mechanical properties; Methods; Production processes; Purification; Sawdust; Sludge; Softwood sawdust; Water; Water treatment; Water treatment sludge; Weight reduction
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2010.12.057

► This is a pioneer study of the combined use of sludge and sawdust to produce a composite. ► The concrete produced with this composite displayed an axial compressive strength of 11.1MPa. ► The concrete produced with this composite displayed a specific mass of 1847kg/m3. In developing countries such as Brazil, the wastes generated in the decanters and filters of water treatment plants are discharged directly into the same rivers and streams that supply water for treatment. Another environmental problem is the unregulated discard of wood wastes. The lumber and wood products industry generates large quantities of this waste, from logging to the manufacture of the end product. Brazil has few biomass plants and therefore only a minor part of these wastes are reused. This paper presents the results of the first study involving a novel scientific and technological approach to evaluate the possibility of combining these two types of wastes in the production of a light-weight composite for concrete. The concrete produced with cement:sand:composite:water mass ratios of 1:2.5:0.67:0.6 displayed an axial compressive strength of 11.1MPa, a compressive and diametral tensile strength of 1.2MPa, water absorption of 8.8%, and a specific mass of 1.847kg/m3. The mechanical properties obtained with this concrete render it suitable for application in non-structural elements.