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Efficiency of Different Superplasticizers and Retarders on Properties of ‘One-Part’ Fly Ash-Slag Blended Geopolymers with Different Activators
Currently, there are a very limited number of studies on the effect of admixtures on properties of ‘one-part’ geopolymers. This paper reports the effects of different superplasticizers and retarders on fresh and hardened properties of one-part fly ash-slag blended geopolymers made by different solid...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2019
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6829244/ https://www.ncbi.nlm.nih.gov/pubmed/31635266 http://dx.doi.org/10.3390/ma12203410 |
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author | Bong, Shin Hau Nematollahi, Behzad Nazari, Ali Xia, Ming Sanjayan, Jay |
author_facet | Bong, Shin Hau Nematollahi, Behzad Nazari, Ali Xia, Ming Sanjayan, Jay |
author_sort | Bong, Shin Hau |
collection | PubMed |
description | Currently, there are a very limited number of studies on the effect of admixtures on properties of ‘one-part’ geopolymers. This paper reports the effects of different superplasticizers and retarders on fresh and hardened properties of one-part fly ash-slag blended geopolymers made by different solid activators. Two different grades of sodium silicate, namely anhydrous sodium metasilicate powder (nSiO(2)/nNa(2)O = 0.9) and GD Grade sodium silicate powder (nSiO(2)/nNa(2)O = 2.0) were used as the solid activators. Five different commercially available superplasticizers, including three modified polycarboxylate-based superplasticizers (denoted as PC1, PC2, and PC3) and two naphthalene-based superplasticizers (denoted as N1 and N2), as well as three different retarders, including sucrose, anhydrous borax and a commercially available retarder, were investigated. Workability, setting time and compressive strength of the mixtures without and with addition of each ‘individual’ admixture were measured. The results showed the effect of admixtures on the properties of the one-part geopolymers significantly depended on the type of solid activator and the type of admixture used. When GD Grade sodium silicate powder was used as the solid activator, all investigated admixtures not only had no positive effect on the workability and setting time, but also significantly reduced the compressive strength of the mixture. However, when anhydrous sodium metasilicate powder was used as the solid activator, the PC1 and sucrose were the best performing superplasticizer and retarder, respectively, causing no reduction in the compressive strength, but significant increase in the workability (up to + 72%) and setting time (up to + 111%), respectively as compared to the mixture with no admixture. In addition, the results also showed that addition of ‘combined’ admixtures (i.e., PC1 in the presence of sucrose) significantly increased the workability (up to + 39%) and setting time (up to + 141%), but slightly reduced the compressive strength (−16%) of the mixture activated by anhydrous sodium metasilicate powder, as compared to the mixture with no admixture. |
format | Online Article Text |
id | pubmed-6829244 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-68292442019-11-18 Efficiency of Different Superplasticizers and Retarders on Properties of ‘One-Part’ Fly Ash-Slag Blended Geopolymers with Different Activators Bong, Shin Hau Nematollahi, Behzad Nazari, Ali Xia, Ming Sanjayan, Jay Materials (Basel) Article Currently, there are a very limited number of studies on the effect of admixtures on properties of ‘one-part’ geopolymers. This paper reports the effects of different superplasticizers and retarders on fresh and hardened properties of one-part fly ash-slag blended geopolymers made by different solid activators. Two different grades of sodium silicate, namely anhydrous sodium metasilicate powder (nSiO(2)/nNa(2)O = 0.9) and GD Grade sodium silicate powder (nSiO(2)/nNa(2)O = 2.0) were used as the solid activators. Five different commercially available superplasticizers, including three modified polycarboxylate-based superplasticizers (denoted as PC1, PC2, and PC3) and two naphthalene-based superplasticizers (denoted as N1 and N2), as well as three different retarders, including sucrose, anhydrous borax and a commercially available retarder, were investigated. Workability, setting time and compressive strength of the mixtures without and with addition of each ‘individual’ admixture were measured. The results showed the effect of admixtures on the properties of the one-part geopolymers significantly depended on the type of solid activator and the type of admixture used. When GD Grade sodium silicate powder was used as the solid activator, all investigated admixtures not only had no positive effect on the workability and setting time, but also significantly reduced the compressive strength of the mixture. However, when anhydrous sodium metasilicate powder was used as the solid activator, the PC1 and sucrose were the best performing superplasticizer and retarder, respectively, causing no reduction in the compressive strength, but significant increase in the workability (up to + 72%) and setting time (up to + 111%), respectively as compared to the mixture with no admixture. In addition, the results also showed that addition of ‘combined’ admixtures (i.e., PC1 in the presence of sucrose) significantly increased the workability (up to + 39%) and setting time (up to + 141%), but slightly reduced the compressive strength (−16%) of the mixture activated by anhydrous sodium metasilicate powder, as compared to the mixture with no admixture. MDPI 2019-10-18 /pmc/articles/PMC6829244/ /pubmed/31635266 http://dx.doi.org/10.3390/ma12203410 Text en © 2019 by the authors. 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 (http://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Bong, Shin Hau Nematollahi, Behzad Nazari, Ali Xia, Ming Sanjayan, Jay Efficiency of Different Superplasticizers and Retarders on Properties of ‘One-Part’ Fly Ash-Slag Blended Geopolymers with Different Activators |
title | Efficiency of Different Superplasticizers and Retarders on Properties of ‘One-Part’ Fly Ash-Slag Blended Geopolymers with Different Activators |
title_full | Efficiency of Different Superplasticizers and Retarders on Properties of ‘One-Part’ Fly Ash-Slag Blended Geopolymers with Different Activators |
title_fullStr | Efficiency of Different Superplasticizers and Retarders on Properties of ‘One-Part’ Fly Ash-Slag Blended Geopolymers with Different Activators |
title_full_unstemmed | Efficiency of Different Superplasticizers and Retarders on Properties of ‘One-Part’ Fly Ash-Slag Blended Geopolymers with Different Activators |
title_short | Efficiency of Different Superplasticizers and Retarders on Properties of ‘One-Part’ Fly Ash-Slag Blended Geopolymers with Different Activators |
title_sort | efficiency of different superplasticizers and retarders on properties of ‘one-part’ fly ash-slag blended geopolymers with different activators |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6829244/ https://www.ncbi.nlm.nih.gov/pubmed/31635266 http://dx.doi.org/10.3390/ma12203410 |
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