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A platform for research: civil engineering, architecture and urbanism
Structural deterioration of calcium aluminosilicate hydrate by sulfate attack: Atomic processes of Al-Si chain breaking
https://orcid.org/0000-0002-1252-2987
Highlights Employs semi-empirical quantum mechanics method to reproduce the atomic process of sulfate attack on C-A-S-H. Reveals the interacting mechanism of sulfate attack on C-A-S-H. Suggests that the low bond dissociation energy of Al-O are responsible for facile dealumination and explains its origin.
Abstract Calcium-aluminosilicate-hydrates (C-A-S-H) is the major hydration product of sustainable concrete that incorporates industrial waste as a partial substitute for cement. Although C-A-S-H is considered a durable material, it’s susceptible to sulfate attack. To better understand this phenomenon, the atomic process of sulfate attack on C-A-S-H was studied using semi-empirical quantum chemical methods. The results showed that sulfate attacks can be broken down into several subprocesses: adsorption, vibration, and breaking. The underlying causes of these processes were revealed through electronic structures, in which the weak AlO bond and strong electronegativity are the main factors leading to Al-Si breaking. The Atom in Molecular theory revealed that the weak electron localization of the [AlO4] tetrahedron leads to a lower water-assisted bond dissociated energy for breaking the AlO bond (18.3KJ/mol) than the SiO bond (109.4KJ/mol). This study provides valuable insights into the sulfate attack on C-A-S-H and its implications for improving the durability of sustainable concrete.
Structural deterioration of calcium aluminosilicate hydrate by sulfate attack: Atomic processes of Al-Si chain breaking
https://orcid.org/0000-0002-1252-2987
Highlights Employs semi-empirical quantum mechanics method to reproduce the atomic process of sulfate attack on C-A-S-H. Reveals the interacting mechanism of sulfate attack on C-A-S-H. Suggests that the low bond dissociation energy of Al-O are responsible for facile dealumination and explains its origin.
Abstract Calcium-aluminosilicate-hydrates (C-A-S-H) is the major hydration product of sustainable concrete that incorporates industrial waste as a partial substitute for cement. Although C-A-S-H is considered a durable material, it’s susceptible to sulfate attack. To better understand this phenomenon, the atomic process of sulfate attack on C-A-S-H was studied using semi-empirical quantum chemical methods. The results showed that sulfate attacks can be broken down into several subprocesses: adsorption, vibration, and breaking. The underlying causes of these processes were revealed through electronic structures, in which the weak AlO bond and strong electronegativity are the main factors leading to Al-Si breaking. The Atom in Molecular theory revealed that the weak electron localization of the [AlO4] tetrahedron leads to a lower water-assisted bond dissociated energy for breaking the AlO bond (18.3KJ/mol) than the SiO bond (109.4KJ/mol). This study provides valuable insights into the sulfate attack on C-A-S-H and its implications for improving the durability of sustainable concrete.
Structural deterioration of calcium aluminosilicate hydrate by sulfate attack: Atomic processes of Al-Si chain breaking
https://orcid.org/0000-0002-1252-2987
Highlights Employs semi-empirical quantum mechanics method to reproduce the atomic process of sulfate attack on C-A-S-H. Reveals the interacting mechanism of sulfate attack on C-A-S-H. Suggests that the low bond dissociation energy of Al-O are responsible for facile dealumination and explains its origin.
Abstract Calcium-aluminosilicate-hydrates (C-A-S-H) is the major hydration product of sustainable concrete that incorporates industrial waste as a partial substitute for cement. Although C-A-S-H is considered a durable material, it’s susceptible to sulfate attack. To better understand this phenomenon, the atomic process of sulfate attack on C-A-S-H was studied using semi-empirical quantum chemical methods. The results showed that sulfate attacks can be broken down into several subprocesses: adsorption, vibration, and breaking. The underlying causes of these processes were revealed through electronic structures, in which the weak AlO bond and strong electronegativity are the main factors leading to Al-Si breaking. The Atom in Molecular theory revealed that the weak electron localization of the [AlO4] tetrahedron leads to a lower water-assisted bond dissociated energy for breaking the AlO bond (18.3KJ/mol) than the SiO bond (109.4KJ/mol). This study provides valuable insights into the sulfate attack on C-A-S-H and its implications for improving the durability of sustainable concrete.
Structural deterioration of calcium aluminosilicate hydrate by sulfate attack: Atomic processes of Al-Si chain breaking
Hou, Dongshuai (author) / Wang, Meng (author) / Sun, Huiwen (author) / Wang, Pan (author) / Zhang, Jun (author) / Wang, Muhan (author)
2023-08-02
Article (Journal)
Electronic Resource
English
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