Multicriteria sustainability assessment of biocomposites of magnesium-based fiber cement and agroindustrial ash

• Ano de defesa: 2024
• Autor(a) principal: Gavioli, Letícia Missiatto
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: Accelerated aging; ACV; Cellulosic fibers; Cimento magnesiano; Compósitos sustentáveis; Envelhecimento acelerado; Fibras celulósicas; LCA; Magnesium cement; Sustainable composites
• Link de acesso: https://www.teses.usp.br/teses/disponiveis/74/74133/tde-18092024-160227/

New low-alkalinity matrices, such as magnesium-based M-S-H cement, which combines magnesium oxide (MgO) and silica dioxide (SiO2), are currently under study due to their ability to preserve plant fibers and indications of lower CO2 emissions. Bamboo leaf ash (BLAsh) has also been researched as a pozzolan for addition to matrices with Portland cement. However, there have been no studies found regarding the use of BLAsh in MSH fiber cement, addressing not only its functional performance but also a sustainability analysis. Therefore, this study aims to develop formulations of M-S-H fiber cement, comparing them with Portland cement using the extrusion method and replacing limestone with BLAsh and unbleached pine cellulose pulp. Additionally, the study seeks to evaluate physical, mechanical, and durability properties through accelerated aging cycles. For the multi-criteria sustainability analysis, considerations were given not only to functional performance but also to environmental performance through a life cycle assessment (LCA) and economic performance through the calculation of Construction Cost (CC). In the environmental analysis of BLAsh production, scenarios considered included ash as waste, new by-product, and co-product. Results indicate that Portland cement composites showed better functional and economic performance, while MSH cement composites stood out for superior environmental performance. In both cases, the use of BLAsh improved performance. The panel that demonstrated the highest level of sustainability was the one using Portland cement fiberboard and BLAsh with the waste scenario.