Cimentos álcali ativados: efeito da cura térmica no desenvolvimento da resistência mecânica

Abstract

Due to the extraction of non-renewable raw materials and the release of CO2 into the atmosphere by the production of Portland Cement, the production of alkali-activated cements has been gaining ground on the world stage. The production of CAT's does not involve calcination of materials and uses by-products of the steel industry. Thus, they are classified as a new products of low environmental impact and with binding properties for employment in construction. Its raw material is activated blast furnace slag, which may be from furnaces to charcoal and coke, which modifies its chemical composition. In this work, the objective is to improve the strength of the CAT's (Activated alkali cements) by thermal curing using two types of slag of different chemical compositions (slag A and B), with 5% of alkaline activator subjected to a thermal wet cure lasting 24 hours At temperatures of 400 C and 600 C. The mechanical strength of the mortars was evaluated at ages 24, 3, 7 and 28 days, where better results were obtained for the slag A, which was cured at 40 ° C. Thermal analysis was also performed for the slags of both slags, where formation was observed for both slag C-S-H and hydrotalcite for slag B, which may have influence on mechanical strength.