Chloride Permeability of Alkali-Activated Slag Concretes after Exposure to High Temperatures

The number of fires in buildings and on bridges has increased worldwide in recent years. As a structural material, the strength of alkali-activated slag (AAS) concrete after exposure to high temperatures has been given much attention. However, research of its durability is still lacking, which limit...

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Main Authors: Baomeng Zhou, Qianmin Ma, Rongxin Guo, Ping Li
Format: Article
Language:English
Published: MDPI AG 2024-02-01
Series:Materials
Subjects:
Online Access:https://www.mdpi.com/1996-1944/17/5/1028
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author Baomeng Zhou
Qianmin Ma
Rongxin Guo
Ping Li
author_facet Baomeng Zhou
Qianmin Ma
Rongxin Guo
Ping Li
author_sort Baomeng Zhou
collection DOAJ
description The number of fires in buildings and on bridges has increased worldwide in recent years. As a structural material, the strength of alkali-activated slag (AAS) concrete after exposure to high temperatures has been given much attention. However, research of its durability is still lacking, which limits the application of this type of concrete on a larger scale. In this context, as one of the most important aspects of durability, the chloride permeability of AAS concretes after exposure to high temperatures was examined in this study. The influence of the alkali concentration (Na<sub>2</sub>O%) and the modulus (Ms) of the activator, as well as the influence of heating regimes, including the heating rate, duration of exposure to the target temperature, and cooling method, was also discussed. The results show that the chloride permeability of the AAS concretes increased with temperature elevation. Due to the interference of pore solution conductivity, the influence of the Na<sub>2</sub>O% and the Ms of the activator on the chloride permeability of the AAS concretes was not made clear by using the ASTM C 1202 charge passed method; however, after exposure to high temperatures, AAS with a lower Na<sub>2</sub>O% and lower Ms has lower porosity and may have lower chloride permeability, which needs further investigation. Faster heating for a longer duration at the target temperature and water cooling reduced the resistance of the AAS concretes to chloride permeability as a result of their increased porosity.
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spelling doaj.art-30e5d0fb76934c5593cc03a60b03bd572024-03-12T16:49:00ZengMDPI AGMaterials1996-19442024-02-01175102810.3390/ma17051028Chloride Permeability of Alkali-Activated Slag Concretes after Exposure to High TemperaturesBaomeng Zhou0Qianmin Ma1Rongxin Guo2Ping Li3Faculty of Civil Engineering and Mechanics, Kunming University of Science and Technology, Kunming 650500, ChinaFaculty of Civil Engineering and Mechanics, Kunming University of Science and Technology, Kunming 650500, ChinaFaculty of Civil Engineering and Mechanics, Kunming University of Science and Technology, Kunming 650500, ChinaFaculty of Civil Engineering and Mechanics, Kunming University of Science and Technology, Kunming 650500, ChinaThe number of fires in buildings and on bridges has increased worldwide in recent years. As a structural material, the strength of alkali-activated slag (AAS) concrete after exposure to high temperatures has been given much attention. However, research of its durability is still lacking, which limits the application of this type of concrete on a larger scale. In this context, as one of the most important aspects of durability, the chloride permeability of AAS concretes after exposure to high temperatures was examined in this study. The influence of the alkali concentration (Na<sub>2</sub>O%) and the modulus (Ms) of the activator, as well as the influence of heating regimes, including the heating rate, duration of exposure to the target temperature, and cooling method, was also discussed. The results show that the chloride permeability of the AAS concretes increased with temperature elevation. Due to the interference of pore solution conductivity, the influence of the Na<sub>2</sub>O% and the Ms of the activator on the chloride permeability of the AAS concretes was not made clear by using the ASTM C 1202 charge passed method; however, after exposure to high temperatures, AAS with a lower Na<sub>2</sub>O% and lower Ms has lower porosity and may have lower chloride permeability, which needs further investigation. Faster heating for a longer duration at the target temperature and water cooling reduced the resistance of the AAS concretes to chloride permeability as a result of their increased porosity.https://www.mdpi.com/1996-1944/17/5/1028alkali-activated slag concretehigh temperaturechloride permeabilitypore structure
spellingShingle Baomeng Zhou
Qianmin Ma
Rongxin Guo
Ping Li
Chloride Permeability of Alkali-Activated Slag Concretes after Exposure to High Temperatures
Materials
alkali-activated slag concrete
high temperature
chloride permeability
pore structure
title Chloride Permeability of Alkali-Activated Slag Concretes after Exposure to High Temperatures
title_full Chloride Permeability of Alkali-Activated Slag Concretes after Exposure to High Temperatures
title_fullStr Chloride Permeability of Alkali-Activated Slag Concretes after Exposure to High Temperatures
title_full_unstemmed Chloride Permeability of Alkali-Activated Slag Concretes after Exposure to High Temperatures
title_short Chloride Permeability of Alkali-Activated Slag Concretes after Exposure to High Temperatures
title_sort chloride permeability of alkali activated slag concretes after exposure to high temperatures
topic alkali-activated slag concrete
high temperature
chloride permeability
pore structure
url https://www.mdpi.com/1996-1944/17/5/1028
work_keys_str_mv AT baomengzhou chloridepermeabilityofalkaliactivatedslagconcretesafterexposuretohightemperatures
AT qianminma chloridepermeabilityofalkaliactivatedslagconcretesafterexposuretohightemperatures
AT rongxinguo chloridepermeabilityofalkaliactivatedslagconcretesafterexposuretohightemperatures
AT pingli chloridepermeabilityofalkaliactivatedslagconcretesafterexposuretohightemperatures