Durability assessment of MgO-based fiber cement reinforced with lignocellulosic fibers and cured in a CO2-rich atmosphere

Autor(es)

Azevedo, A. G. S. ; Baltazar, L. ; Faria, P. ; Savastano, H.

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF BUILDING ENGINEERING; v. 104, p. 20-pg., 2025-06-15.

Resumo

This study investigates the durability and performance of fiber cement composites produced from magnesium oxysulfate (MOS) matrices reinforced with lignocellulosic fibers, subjected to accelerated carbonation. The composites underwent mechanical, physical, and chemical characterization through flexural strength tests, X-ray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) after various aging cycles. Durability was assessed via freeze-thaw, soak-and-dry, and UV exposure tests. Carbonation led to a reduction in mechanical strength, which is attributed to the reaction of CO2 with phase 5-1-7, a key component responsible for strength development. The formation of new carbonation products, confirmed by TGA and SEM, modified the physical properties of the composites. The changes in physical properties clearly demonstrate that accelerated carbonation promoted the formation of Hydrated Magnesium Carbonates (HMCs), which precipitated in voids, thereby increasing the density of the fiber cements. XRD analysis showed a reduction in the phase 5-1-7 peak intensity following CO2 exposure, corroborating the carbonation process. These results contribute to optimizing curing processes and durability treatments, enhancing the applicability of MOS-based composites in construction, particularly for prefabricated panels and non-structural walling systems exposed to different weather conditions. (AU)

• Processo FAPESP: 21/04780-7 - Estudo da durabilidade em compósitos cimentícios reforçados com fibras lignocelulósicas com matrizes com MgO e MgSO4
• Beneficiário: Adriano Galvão de Souza Azevedo
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 14/50948-3 - INCT 2014: tecnologias ecoeficientes avançadas em produtos cimentícios
• Beneficiário: Vanderley Moacyr John
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 24/02445-4 - Uso de Sementes de Nucleação no Aumento da Captura e Mineralização do CO2 Proveniente da Indústria Sucroalcooleira em Fibrocimentos Low-Carb
• Beneficiário: Adriano Galvão de Souza Azevedo
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 22/07179-5 - Avaliação da durabilidade de fibrocimentos de matriz MOS reforçados com fibras lignocelulósicas e submetidos à processos de carbonatação acelerada
• Beneficiário: Adriano Galvão de Souza Azevedo
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado