Évaluation de brasques traitées comme ajout cimentaire dans le béton

Abstract

Cement is the most used material in the concrete manufacturing and construction industries. The use of supplementary cementitious materials is becoming more important as it contributes to the reduction of CO2 emissions by replacing the cement in certain percentages. Many of the additions used today are waste from other industries. However, these industrial wastes do not have an infinite production. It is therefore necessary to search for new materials that meet the requirements for use as a supplementary cementitious material and at the same time obtain benefits in the reduction in the carbon footprint and in production costs in the construction industry. For this research, the objective of the study is focused on treated spent pot lining (SPL) by Low-Caustic Leaching and Liming process (BT-LCLL) from the primary aluminum industry, as supplementary cementitious materials, which is a demonstration of the circular economy. This material, derived from a process created by the Canadian company Rio Tinto Alcan, has not yet been studied extensively. Indeed, several years of research were needed to reduce the fluoride and cyanide content and make the BT-LCLL acceptable for its use. Various scales of evaluation have been established for the analysis of this material. At the powder level, the material was analyzed by methods such as X-ray diffraction (XRD), scanning electron microscopy (SEM), particle size and surface area. At the mortar level, the pozzolanic activity test was measured by the strength activity index (SAI). The cement pastes were prepared with different water/binder ratios and thermogravimetric analysis (TGA), SEM and XRD tests were performed. Experimental results indicate that SPL is a potentially supplementary cementitious material with an optimal cement replacement rate of 10%. The lack of information and previous studies make it necessary to continue the in-depth studies on this replacement product. Research in this direction would provide a better understanding of the product, to formulate effective solutions to problems related to the growing production of concrete.

Date	1 Mar 2019
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Claudiane Ouellet-Plamondon (Supervisor)