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Published in Southern Africa Materials Science Symposium 2025. This article was peer reviewed before publication.
Karoo Institute of Advanced Materials
Cellulose nanofibre reinforcement of geopolymer cement from coal fly ash
Abstract
Geopolymer cements offer a lower-carbon alternative to Portland cement but can be brittle. We reinforced a fly-ash geopolymer with cellulose nanofibres extracted from agricultural residue and measured flexural strength, toughness, and drying shrinkage. A one percent nanofibre loading increased flexural toughness by 34 percent and reduced shrinkage cracking without compromising compressive strength. We discuss dispersion methods that avoid nanofibre agglomeration.
Keywords: Geopolymer, Fly ash, Cellulose nanofibres, Low-carbon cement
Cite as: Lindiwe Zulu & Sipho Khumalo (2025). Cellulose nanofibre reinforcement of geopolymer cement from coal fly ash. Southern Africa Materials Science Symposium 2025. https://quorumpress.org/papers/cellulose-nanofibre-reinforcement-geopolymer-42wb5
© 2025 Zulu and Khumalo. Open access under CC BY 4.0.
Introduction
Geopolymer binders can cut the embodied carbon of construction, but their brittleness limits structural use. Bio-based nanofibre reinforcement is a promising toughening route.
Methods
Cellulose nanofibres from agricultural residue were dispersed into a fly-ash geopolymer at loadings up to two percent. We tested flexural strength, toughness, and drying shrinkage.
Results
One percent loading raised flexural toughness by 34 percent and reduced shrinkage cracking while maintaining compressive strength; higher loadings suffered from agglomeration.
Cite this paper
Lindiwe Zulu, Sipho Khumalo. Cellulose nanofibre reinforcement of geopolymer cement from coal fly ash. Southern Africa Materials Science Symposium 2025, 2025. https://quorumpress.org/papers/cellulose-nanofibre-reinforcement-geopolymer-42wb5
Publication ID: 42wb5