Back to basics: Nanomodulating calcium silicate hydrate gels to mitigate CO2 footprint of concrete industry
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2024-01Rights
© 2023 Elsevier Ltd. All rights reserved. Reproduced in accordance with the publisher's self-archiving policy. This manuscript version is made available under the CC-BY-NC-ND 4.0 license.Peer-Reviewed
YesOpen Access status
embargoedAccessAccepted for publication
2023-11-24
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To realize the sustainable development of concrete, it is vital to mitigate its consumption and environmental footprint (especially CO2 footprint) from prolonging the service life through upgrading mechanical and durable performances of concrete. Incorporating nanofillers can effectively tailor the microstructures and performances of bulk cement paste and cement paste at interfacial transition zone in concrete. The hydrated calcium silicate (C–S–H) gels account for half of the volume of hardened Portland cement pastes, and they are the fundamental source of overall properties of concrete. However, the underlying mechanisms of nanofillers on C–S–H gels remains unclear. Herein, this paper underpinned the role of 5 types of representative nanofillers in tailoring the nanostructure of C–S–H gels in cement composites. The research results demonstrated that through the nano-core effect, nanofillers induce the formation of two new C–S–H gels in outer hydration products, namely nano-core-shell element doped low-density C–S–H (NEDLD C–S–H) and nano-core-shell element doped high-density C–S–H (NEDHD C–S–H). The indentation modulus/hardness of NEDLD and NEDHD C–S–H reaches 25.4/0.80 GPa and 46.7/2.72 GPa, respectively. Such superior performances of NEDLD and NEDHD C–S–H derive from the existence of nano-core-shell elements in C–S–H gels rather than the increase in C–S–H packing density. In a short-range, nanofillers form nano-core-shell elements by adsorbing silica tetrahedrons during the hydration process, improving the mechanical properties of C–S–H basic building blocks. In the long-range, the nano-core-shell elements modify the nano-scale performances of C–S–H gels in outer hydration products due to the increase of C–S–H gels’ integrality.Version
Accepted manuscriptCitation
Wang X, Ding S, Ashour A et al (2023) Back to basics: Nanomodulating calcium silicate hydrate gels to mitigate CO2 footprint of concrete industry. Journal of Cleaner Production. 434: 139921.Link to Version of Record
https://doi.org/10.1016/j.jclepro.2023.139921Type
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The full-text of this article will be released for public view at the end of the publisher embargo on 01 Dec 2024.ae974a485f413a2113503eed53cd6c53
https://doi.org/10.1016/j.jclepro.2023.139921