This paper presents an investigation into the use of water works and wastewater (W & WW) sludge as an alternative raw material for cement production. The goal of this research was to provide a preliminary evaluation of the cementitious properties of W & WW sludge when used in the production of concrete after being sintered at different temperatures (800°C and 1100°C). Heat-treated sludge was incorporated into the manufacturing stage of concrete mortar as a replacement for a percentage of Portland cement. A series of 50 mm cube concrete prisms were cast containing different concentrations of W & WW sludge, ranging from 0 to 10%. The prisms were tested for compressive strength after curing periods of 7, 28 and 56-days. The highest heat treatment level of 1100°C showed some improvement in compressive strength up to 7.5%, however the trends were not consistent since results fluctuated between the 2.5% and 10% replacement levels. Results of wastewater sludge treated at 800°C also fluctuated between those levels. Water works sludge treated at 800°C proved to have the most beneficial effect, with compressive strengths for all replacement levels higher than the control specimens. Additional prisms were then cast using 800°C waterworks sludge and the tensile strength of the concrete was determined after seven days by means of a double-punching test. This study contributes to the increasing body of research regarding the use of W &WW in building materials, and suggests the potential benefits of its use in concrete for the purpose of sustainable infrastructure renewal.

Annual Conference of the Canadian Society for Civil Engineering 2010, CSCE 2010
Department of Civil and Environmental Engineering

Jardine, B., Basu, O, & Sherwood, E.G. (2010). Investigation into alternative raw material for cement production. Presented at the Annual Conference of the Canadian Society for Civil Engineering 2010, CSCE 2010.