Hydration and structure formation of chloride-activated cement paste

The result of the research is the formulation of chloride-activated high-strength cement paste with accelerated hardening, increased strength, and without heat treatment. The cement paste was activated by introducing a chloride-containing additive into the cement-water system. The additive was synth...

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Main Authors: Tatiana Shepelenko, Nikolai Vatin, Olga Zubkova
Format: Article
Language:English
Published: Peter the Great St. Petersburg Polytechnic University 2020-12-01
Series:Magazine of Civil Engineering
Subjects:
Online Access:https://engstroy.spbstu.ru/en/article/2020.100.9/
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author Tatiana Shepelenko
Nikolai Vatin
Olga Zubkova
author_facet Tatiana Shepelenko
Nikolai Vatin
Olga Zubkova
author_sort Tatiana Shepelenko
collection DOAJ
description The result of the research is the formulation of chloride-activated high-strength cement paste with accelerated hardening, increased strength, and without heat treatment. The cement paste was activated by introducing a chloride-containing additive into the cement-water system. The additive was synthesized by keeping the cement in a 3 % hydrochloric acid solution, i.e. under conditions of acid corrosion of the binder. The additive is the solid part of the cement-HCl suspension, aged for 24 hours at a ratio of solid and liquid phases of 1:10. The optimized amount of additive is 5 % by weight of dry cement. The effect of the additive on the hardening kinetics, structure, and strength of the activated cement paste was studied. It was established that acid corrosion products of cement have structure-forming activity. A significant increase of the compressive strength of the activated cement paste relative to the control sample was found over the entire hardening interval (1–3–7–28 days). At the daily age of normal hardening, the strength of activated cement paste increased by 165 %. At 28 days of age, the strength increased by 42 %. The X-ray phase and infrared spectral analysis results suggest the following. The acceleration of setting and the increase in the strength of the cement composite is realized due to the intensification of hydration processes and the binding of portlandite, the early formation of structure-forming phases as ettringite and Kuzel salt Са4Al2(ОН)12Cl(SO4)0.5∙6H2O (analog of Friedel’s salt), as well as weakly crystallized calcium hydrosilicates with a tobermorite-like structure.
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spelling doaj.art-3958412e16e94eba8c6b5f499767b71d2022-12-21T21:30:45ZengPeter the Great St. Petersburg Polytechnic UniversityMagazine of Civil Engineering2712-81722712-81722020-12-011008100091000910.18720/MCE.100.9Hydration and structure formation of chloride-activated cement pasteTatiana Shepelenko0Nikolai Vatin1https://orcid.org/0000-0002-1196-8004Olga Zubkova2Tomsk State University of Architecture and BuildingPeter the Great St. Petersburg Polytechnic UniversityTomsk State University of Architecture and BuildingThe result of the research is the formulation of chloride-activated high-strength cement paste with accelerated hardening, increased strength, and without heat treatment. The cement paste was activated by introducing a chloride-containing additive into the cement-water system. The additive was synthesized by keeping the cement in a 3 % hydrochloric acid solution, i.e. under conditions of acid corrosion of the binder. The additive is the solid part of the cement-HCl suspension, aged for 24 hours at a ratio of solid and liquid phases of 1:10. The optimized amount of additive is 5 % by weight of dry cement. The effect of the additive on the hardening kinetics, structure, and strength of the activated cement paste was studied. It was established that acid corrosion products of cement have structure-forming activity. A significant increase of the compressive strength of the activated cement paste relative to the control sample was found over the entire hardening interval (1–3–7–28 days). At the daily age of normal hardening, the strength of activated cement paste increased by 165 %. At 28 days of age, the strength increased by 42 %. The X-ray phase and infrared spectral analysis results suggest the following. The acceleration of setting and the increase in the strength of the cement composite is realized due to the intensification of hydration processes and the binding of portlandite, the early formation of structure-forming phases as ettringite and Kuzel salt Са4Al2(ОН)12Cl(SO4)0.5∙6H2O (analog of Friedel’s salt), as well as weakly crystallized calcium hydrosilicates with a tobermorite-like structure.https://engstroy.spbstu.ru/en/article/2020.100.9/cements hydrationhydrated cement pastestructure formationhydrochloric acidbinder additivehydratessilicatessilicate mineralsstrengthacid corrosionaccelerating admixturesaccelerating effectkuzel's saltfriedel's salt
spellingShingle Tatiana Shepelenko
Nikolai Vatin
Olga Zubkova
Hydration and structure formation of chloride-activated cement paste
Magazine of Civil Engineering
cements hydration
hydrated cement paste
structure formation
hydrochloric acid
binder additive
hydrates
silicates
silicate minerals
strength
acid corrosion
accelerating admixtures
accelerating effect
kuzel's salt
friedel's salt
title Hydration and structure formation of chloride-activated cement paste
title_full Hydration and structure formation of chloride-activated cement paste
title_fullStr Hydration and structure formation of chloride-activated cement paste
title_full_unstemmed Hydration and structure formation of chloride-activated cement paste
title_short Hydration and structure formation of chloride-activated cement paste
title_sort hydration and structure formation of chloride activated cement paste
topic cements hydration
hydrated cement paste
structure formation
hydrochloric acid
binder additive
hydrates
silicates
silicate minerals
strength
acid corrosion
accelerating admixtures
accelerating effect
kuzel's salt
friedel's salt
url https://engstroy.spbstu.ru/en/article/2020.100.9/
work_keys_str_mv AT tatianashepelenko hydrationandstructureformationofchlorideactivatedcementpaste
AT nikolaivatin hydrationandstructureformationofchlorideactivatedcementpaste
AT olgazubkova hydrationandstructureformationofchlorideactivatedcementpaste