Innovative Clinker-Free and Low-Alkalinity MgO-Aluminosilicate Binders for Durable Natural Fiber Composites: Advancing the Brazilian Bioeconomy

• Grant number: 25/01507-9
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: September 01, 2025
• End date: August 31, 2028
• Field of knowledge: Engineering - Civil Engineering - Construction Industry
• Principal Investigator: Holmer Savastano Junior
• Grantee: Maria Júlia Bassan de Moraes
• Host Institution: Faculdade de Zootecnia e Engenharia de Alimentos (FZEA). Universidade de São Paulo (USP). Pirassununga , SP, Brazil
• Associated research grant: 23/02750-9 - Alkaline waste-based materials and low-carbon agroindustrial processes as modernization tools in constructive applications, AP.JP

Abstract

The construction industry of the future will not be limited to innovations in methods and materials but will be grounded in fundamental pillars of sustainability, eco-efficiency, and circular economy to minimize environmental impact. Portland cement, widely used today, is associated with high CO¿ emissions, significant energy demand, and incompatibility with vegetable fibers due to its alkalinity. In this context, MgO-based cements emerge as a promising alternative, standing out for their low alkalinity and reduced environmental footprint. The objective of this research is to explore the potential of MgO-Aluminosilicate cements in matrices reinforced with cellulose pulps, aiming for applications in the fiber-cement industry. Additionally, it seeks to develop an optimized composite that combines low alkalinity, reduced energy demand, low CO¿ emissions, high mechanical performance, and durability. The project also aims to valorize national resources, aligning with bioeconomy principles and promoting sustainable economic development in Brazil. As a strategic outcome, the project strengthens the expertise of the NAP BioSMat/USP group in developing MgO-based cements, inaugurating a dedicated research line focused on MgO-SiO¿-Al¿O¿ systems (M-(A)-S-H Cements). The project will be structured into three interdependent phases: (i) investigation of the impact of the proportions between magnesium and aluminosilicate sources on the matrix properties and the performance of fiber cement reinforced with cellulosic pulps, (ii) analysis of the effects of curing conditions and various treatments applied to fibers in MgO-SiO¿-Al¿O¿ matrices, and (iii) comparative evaluation of the mechanical and durability performance of composites reinforced with Portland cement-based matrices and MgO-SiO¿-Al¿O¿ and MgO-SiO¿ systems. Each phase will employ advanced techniques for microstructural characterization, physical property analysis, mechanical performance testing, monitoring of dimensional stability, and pH evolution. Furthermore, the project will foster the development of specialized human resources. In the final phase, durability studies will be conducted under natural and accelerated degradation processes, alongside a life cycle assessment to evaluate the environmental performance of the developed composites.