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The Mechanical Properties and Water-Reducing and Retarding Mechanism of a Xylonic Cement Admixture
This study explores the mechanical properties, as well as the water-reducing and setting delay mechanism, of a novel xylonic acid-based water reducer applied to cementitious materials. Four xylonic acid water reducers were synthesized in this study: XACa (PX) from pure xylose, XACa (HS) from hemicel...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2023
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10672015/ https://www.ncbi.nlm.nih.gov/pubmed/38005026 http://dx.doi.org/10.3390/ma16227096 |
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author | Han, Feng Huang, Kaijian Wei, Yang Han, Jian Xu, Yong |
author_facet | Han, Feng Huang, Kaijian Wei, Yang Han, Jian Xu, Yong |
author_sort | Han, Feng |
collection | PubMed |
description | This study explores the mechanical properties, as well as the water-reducing and setting delay mechanism, of a novel xylonic acid-based water reducer applied to cementitious materials. Four xylonic acid water reducers were synthesized in this study: XACa (PX) from pure xylose, XACa (HS) from hemicellulose hydrolysate, XANa (PX) from pure xylose, and XANa (HS) from hemicellulose hydrolysate. These were generated through the whole-cell catalysis of Gluconobacter oxydans bacteria, using pure xylose and hemicellulose hydrolysate as substrates. The findings indicate that the xylonic acid-based water reducer can attain a water-reducing capability between 14% and 16% when the dosage (expressed as a mass fraction of cement) is roughly 0.2%. In initial and final setting tests, XACa (PX) demonstrated a pronounced retarding influence at admixture levels below 0.15%, reaching its apex at 0.10%. This delayed the initial setting time by 76% and the final setting time by 136% relative to the control group. However, a slight pro-setting effect was noted beyond a 0.2% dosage. In the compressive and flexural tests of concrete, under the same slump, the XA group improved its mechanical properties by 5% to 10% compared to the SodiuM lignosulfonate (SL) group. In the air content and chloride ion migration resistance tests, the XA group reduced the air content by 38% compared to the SL group, but also increased the data of rapid chloride migration (D(RCM)) by 16%. Characterization studies revealed that the carboxyl and hydroxyl groups in xylonic acid undergo chemisorption with the Si-O bonds on the surface of cement particles. These groups interact with the Si-O bonds on cement particles, contributing to water-reducing effects and delaying the setting process by impeding Ca(2+) ion aggregation in the calcium-silicate-hydrate gel. Its significant water-reducing effect, adjustable setting time, and excellent mechanical and durability properties suggest its viability as an alternative to lignosulfonate series water-reducing agents. |
format | Online Article Text |
id | pubmed-10672015 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2023 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-106720152023-11-09 The Mechanical Properties and Water-Reducing and Retarding Mechanism of a Xylonic Cement Admixture Han, Feng Huang, Kaijian Wei, Yang Han, Jian Xu, Yong Materials (Basel) Article This study explores the mechanical properties, as well as the water-reducing and setting delay mechanism, of a novel xylonic acid-based water reducer applied to cementitious materials. Four xylonic acid water reducers were synthesized in this study: XACa (PX) from pure xylose, XACa (HS) from hemicellulose hydrolysate, XANa (PX) from pure xylose, and XANa (HS) from hemicellulose hydrolysate. These were generated through the whole-cell catalysis of Gluconobacter oxydans bacteria, using pure xylose and hemicellulose hydrolysate as substrates. The findings indicate that the xylonic acid-based water reducer can attain a water-reducing capability between 14% and 16% when the dosage (expressed as a mass fraction of cement) is roughly 0.2%. In initial and final setting tests, XACa (PX) demonstrated a pronounced retarding influence at admixture levels below 0.15%, reaching its apex at 0.10%. This delayed the initial setting time by 76% and the final setting time by 136% relative to the control group. However, a slight pro-setting effect was noted beyond a 0.2% dosage. In the compressive and flexural tests of concrete, under the same slump, the XA group improved its mechanical properties by 5% to 10% compared to the SodiuM lignosulfonate (SL) group. In the air content and chloride ion migration resistance tests, the XA group reduced the air content by 38% compared to the SL group, but also increased the data of rapid chloride migration (D(RCM)) by 16%. Characterization studies revealed that the carboxyl and hydroxyl groups in xylonic acid undergo chemisorption with the Si-O bonds on the surface of cement particles. These groups interact with the Si-O bonds on cement particles, contributing to water-reducing effects and delaying the setting process by impeding Ca(2+) ion aggregation in the calcium-silicate-hydrate gel. Its significant water-reducing effect, adjustable setting time, and excellent mechanical and durability properties suggest its viability as an alternative to lignosulfonate series water-reducing agents. MDPI 2023-11-09 /pmc/articles/PMC10672015/ /pubmed/38005026 http://dx.doi.org/10.3390/ma16227096 Text en © 2023 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Han, Feng Huang, Kaijian Wei, Yang Han, Jian Xu, Yong The Mechanical Properties and Water-Reducing and Retarding Mechanism of a Xylonic Cement Admixture |
title | The Mechanical Properties and Water-Reducing and Retarding Mechanism of a Xylonic Cement Admixture |
title_full | The Mechanical Properties and Water-Reducing and Retarding Mechanism of a Xylonic Cement Admixture |
title_fullStr | The Mechanical Properties and Water-Reducing and Retarding Mechanism of a Xylonic Cement Admixture |
title_full_unstemmed | The Mechanical Properties and Water-Reducing and Retarding Mechanism of a Xylonic Cement Admixture |
title_short | The Mechanical Properties and Water-Reducing and Retarding Mechanism of a Xylonic Cement Admixture |
title_sort | mechanical properties and water-reducing and retarding mechanism of a xylonic cement admixture |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10672015/ https://www.ncbi.nlm.nih.gov/pubmed/38005026 http://dx.doi.org/10.3390/ma16227096 |
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