Advances in the Study of Carbon Nanotube Fibers for Enhancing the Crack Resistance of Geopolymers

Abstract

With increasing societal awareness of environmental protection, the production process of traditional cement has become an area in urgent need of innovation because of its significant carbon emission contributions and generation of industrial solid waste. As a new type of low-carbon cementitious material, geopolymers not only consume less energy and produce fewer carbon emissions but also effectively allow for the reutilization of industrial solid waste, demonstrating its immense potential for further development. However, the inherent brittleness and poor crack resistance of geopolymers limit their structural applications. The crack resistance of concrete can be significantly improved by utilizing self-stressing structures to generate internal stress or by taking prestressed concrete with its unique manufacturing methods. Furthermore, incorporating admixtures to enhance the material's inherent crack resistance presents another viable strategy. Owing to their excellent mechanical properties, carbon nanotube fibers offer new possibilities for addressing these limitations of geopolymers. In this review, the use of carbon nanotubes (CNTs) to enhance geopolymer performance is investigated. A comprehensive analysis of existing studies reveals that the incorporation of CNTs significantly improves the crack resistance and mitigates the brittleness of geopolymers. Optimal overall performance is frequently reported at CNT dosages between 0.12 wt.% and 0.14 wt.%. These findings provide a theoretical foundation for the practical engineering of CNT-reinforced geopolymers and contribute to the development of sustainable construction materials.

Keywords

carbon nanotube fibers / CNT / geopolymer / anti-cracking performance / crack control

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