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Long-Term Physical and Mechanical Properties and Microstructures of Fly-Ash-Based Geopolymer Composite Incorporating Carbide Slag

The long-term property development of fly ash (FA)-based geopolymer (FA–GEO) incorporating industrial solid waste carbide slag (CS) for up to 360 d is still unclear. The objective of this study was to investigate the fresh, physical, and mechanical properties and microstructures of FA–GEO composites...

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Autores principales: Zhao, Xianhui, Wang, Haoyu, Jiang, Linlin, Meng, Lingchao, Zhou, Boyu, Zhang, Jiashuo
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8587911/
https://www.ncbi.nlm.nih.gov/pubmed/34772218
http://dx.doi.org/10.3390/ma14216692
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author Zhao, Xianhui
Wang, Haoyu
Jiang, Linlin
Meng, Lingchao
Zhou, Boyu
Zhang, Jiashuo
author_facet Zhao, Xianhui
Wang, Haoyu
Jiang, Linlin
Meng, Lingchao
Zhou, Boyu
Zhang, Jiashuo
author_sort Zhao, Xianhui
collection PubMed
description The long-term property development of fly ash (FA)-based geopolymer (FA–GEO) incorporating industrial solid waste carbide slag (CS) for up to 360 d is still unclear. The objective of this study was to investigate the fresh, physical, and mechanical properties and microstructures of FA–GEO composites with CS and to evaluate the effects of CS when the composites were cured for 360 d. FA–GEO composites with CS were manufactured using FA (as an aluminosilicate precursor), CS (as a calcium additive), NaOH solution (as an alkali activator), and standard sand (as a fine aggregate). The fresh property and long-term physical properties were measured, including fluidity, bulk density, porosity, and drying shrinkage. The flexural and compressive strengths at 60 d and 360 d were tested. Furthermore, the microstructures and gel products were characterized by scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS). The results show that the additional 20.0% CS reduces the fluidity and increases the conductivity of FA–GEO composites. Bulk densities were decreased, porosities were increased, and drying shrinkages were decreased as the CS content was increased from 0.0% to 20.0% at 360 d. Room temperature is a better curing condition to obtain a higher long-term mechanical strength. The addition of 20.0% CS is more beneficial to the improvement of long-term flexural strength and toughness at room temperature. The gel products in CS–FA–GEO with 20.0% CS are mainly determined as the mixtures of sodium aluminosilicate (N–A–S–H) gel and calcium silicate hydration (C–S–H) gel, besides the surficial pan-alkali. The research results provide an experimental basis for the reuse of CS in various scenarios.
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spelling pubmed-85879112021-11-13 Long-Term Physical and Mechanical Properties and Microstructures of Fly-Ash-Based Geopolymer Composite Incorporating Carbide Slag Zhao, Xianhui Wang, Haoyu Jiang, Linlin Meng, Lingchao Zhou, Boyu Zhang, Jiashuo Materials (Basel) Article The long-term property development of fly ash (FA)-based geopolymer (FA–GEO) incorporating industrial solid waste carbide slag (CS) for up to 360 d is still unclear. The objective of this study was to investigate the fresh, physical, and mechanical properties and microstructures of FA–GEO composites with CS and to evaluate the effects of CS when the composites were cured for 360 d. FA–GEO composites with CS were manufactured using FA (as an aluminosilicate precursor), CS (as a calcium additive), NaOH solution (as an alkali activator), and standard sand (as a fine aggregate). The fresh property and long-term physical properties were measured, including fluidity, bulk density, porosity, and drying shrinkage. The flexural and compressive strengths at 60 d and 360 d were tested. Furthermore, the microstructures and gel products were characterized by scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS). The results show that the additional 20.0% CS reduces the fluidity and increases the conductivity of FA–GEO composites. Bulk densities were decreased, porosities were increased, and drying shrinkages were decreased as the CS content was increased from 0.0% to 20.0% at 360 d. Room temperature is a better curing condition to obtain a higher long-term mechanical strength. The addition of 20.0% CS is more beneficial to the improvement of long-term flexural strength and toughness at room temperature. The gel products in CS–FA–GEO with 20.0% CS are mainly determined as the mixtures of sodium aluminosilicate (N–A–S–H) gel and calcium silicate hydration (C–S–H) gel, besides the surficial pan-alkali. The research results provide an experimental basis for the reuse of CS in various scenarios. MDPI 2021-11-06 /pmc/articles/PMC8587911/ /pubmed/34772218 http://dx.doi.org/10.3390/ma14216692 Text en © 2021 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
Zhao, Xianhui
Wang, Haoyu
Jiang, Linlin
Meng, Lingchao
Zhou, Boyu
Zhang, Jiashuo
Long-Term Physical and Mechanical Properties and Microstructures of Fly-Ash-Based Geopolymer Composite Incorporating Carbide Slag
title Long-Term Physical and Mechanical Properties and Microstructures of Fly-Ash-Based Geopolymer Composite Incorporating Carbide Slag
title_full Long-Term Physical and Mechanical Properties and Microstructures of Fly-Ash-Based Geopolymer Composite Incorporating Carbide Slag
title_fullStr Long-Term Physical and Mechanical Properties and Microstructures of Fly-Ash-Based Geopolymer Composite Incorporating Carbide Slag
title_full_unstemmed Long-Term Physical and Mechanical Properties and Microstructures of Fly-Ash-Based Geopolymer Composite Incorporating Carbide Slag
title_short Long-Term Physical and Mechanical Properties and Microstructures of Fly-Ash-Based Geopolymer Composite Incorporating Carbide Slag
title_sort long-term physical and mechanical properties and microstructures of fly-ash-based geopolymer composite incorporating carbide slag
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8587911/
https://www.ncbi.nlm.nih.gov/pubmed/34772218
http://dx.doi.org/10.3390/ma14216692
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