Long-Term Performance of Mortars with Combined Incorporation of Ladle Furnace Slag and Metakaolin

Ladle furnace slag (LFS) is used as a supplementary cementitious material (SCM) due to its high calcium oxide (CaO) content. Its binding properties are enhanced in the presence of siliceous materials, such as metakaolin (MK), forming a ternary mixture that can directly replace ordinary Portland ceme...

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Main Authors: Tayná Silva, Everton Souza, Eduardo Mariano, Gisleiva Ferreira, Wislei R. Osório
Format: Article
Language:English
Published: MDPI AG 2024-09-01
Series:Buildings
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Online Access:https://www.mdpi.com/2075-5309/14/9/2762
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author Tayná Silva
Everton Souza
Eduardo Mariano
Gisleiva Ferreira
Wislei R. Osório
author_facet Tayná Silva
Everton Souza
Eduardo Mariano
Gisleiva Ferreira
Wislei R. Osório
author_sort Tayná Silva
collection DOAJ
description Ladle furnace slag (LFS) is used as a supplementary cementitious material (SCM) due to its high calcium oxide (CaO) content. Its binding properties are enhanced in the presence of siliceous materials, such as metakaolin (MK), forming a ternary mixture that can directly replace ordinary Portland cement (OPC). However, despite this blend having already been evaluated in alkali-activated mixtures, knowledge about this mixture in situations of direct replacement of OPC by slag is still lacking. This study evaluates the synergistic effects of combining LFS and MK in cementitious mortars. Due to an insufficient hydration reaction observed in the short term, this study focuses on assessing the long-term performance of these mortars. Both the fresh and hardened states at 28 and 180 days are evaluated, and the resulting microstructural characteristics and constituent phases are also examined. After 180 days of curing, the mortar with MK exhibits superior binding activity compared to the results at 28 days. Although the nominal resistance does not show a clear advantage with the application of MK, a significant reduction in the porosity of the mortar is observed. Microstructural analysis indicates that the addition of MK increases the hydration compounds when mixed with LFS. Importantly, the sample containing MK and LFS showed a 42% reduction in cement consumption, highlighting the potential for resource efficiency. Thus, this study contributes to promoting a circular economy between the steelmaking and civil construction sectors.
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spelling doaj-art-d9204f488681437e8eb10b8abd846e272025-08-20T01:56:01ZengMDPI AGBuildings2075-53092024-09-01149276210.3390/buildings14092762Long-Term Performance of Mortars with Combined Incorporation of Ladle Furnace Slag and MetakaolinTayná Silva0Everton Souza1Eduardo Mariano2Gisleiva Ferreira3Wislei R. Osório4Research Group in Sustainable Materials and Technologies (MATS), School of Civil Engineering, Architecture and Urban Design, University of Campinas/UNICAMP, Campinas 13083-889, BrazilResearch Group in Sustainable Materials and Technologies (MATS), School of Civil Engineering, Architecture and Urban Design, University of Campinas/UNICAMP, Campinas 13083-889, BrazilResearch Group in Sustainable Materials and Technologies (MATS), School of Civil Engineering, Architecture and Urban Design, University of Campinas/UNICAMP, Campinas 13083-889, BrazilResearch Group in Sustainable Materials and Technologies (MATS), School of Civil Engineering, Architecture and Urban Design, University of Campinas/UNICAMP, Campinas 13083-889, BrazilResearch Group in Manufacturing Advanced Materials (CPMMA), School of Applied Sciences, University of Campinas/UNICAMP, Limeira 13484-350, BrazilLadle furnace slag (LFS) is used as a supplementary cementitious material (SCM) due to its high calcium oxide (CaO) content. Its binding properties are enhanced in the presence of siliceous materials, such as metakaolin (MK), forming a ternary mixture that can directly replace ordinary Portland cement (OPC). However, despite this blend having already been evaluated in alkali-activated mixtures, knowledge about this mixture in situations of direct replacement of OPC by slag is still lacking. This study evaluates the synergistic effects of combining LFS and MK in cementitious mortars. Due to an insufficient hydration reaction observed in the short term, this study focuses on assessing the long-term performance of these mortars. Both the fresh and hardened states at 28 and 180 days are evaluated, and the resulting microstructural characteristics and constituent phases are also examined. After 180 days of curing, the mortar with MK exhibits superior binding activity compared to the results at 28 days. Although the nominal resistance does not show a clear advantage with the application of MK, a significant reduction in the porosity of the mortar is observed. Microstructural analysis indicates that the addition of MK increases the hydration compounds when mixed with LFS. Importantly, the sample containing MK and LFS showed a 42% reduction in cement consumption, highlighting the potential for resource efficiency. Thus, this study contributes to promoting a circular economy between the steelmaking and civil construction sectors.https://www.mdpi.com/2075-5309/14/9/2762binderternary blend bindereco-friendly materialpozzolanic additioncementitious matrix
spellingShingle Tayná Silva
Everton Souza
Eduardo Mariano
Gisleiva Ferreira
Wislei R. Osório
Long-Term Performance of Mortars with Combined Incorporation of Ladle Furnace Slag and Metakaolin
Buildings
binder
ternary blend binder
eco-friendly material
pozzolanic addition
cementitious matrix
title Long-Term Performance of Mortars with Combined Incorporation of Ladle Furnace Slag and Metakaolin
title_full Long-Term Performance of Mortars with Combined Incorporation of Ladle Furnace Slag and Metakaolin
title_fullStr Long-Term Performance of Mortars with Combined Incorporation of Ladle Furnace Slag and Metakaolin
title_full_unstemmed Long-Term Performance of Mortars with Combined Incorporation of Ladle Furnace Slag and Metakaolin
title_short Long-Term Performance of Mortars with Combined Incorporation of Ladle Furnace Slag and Metakaolin
title_sort long term performance of mortars with combined incorporation of ladle furnace slag and metakaolin
topic binder
ternary blend binder
eco-friendly material
pozzolanic addition
cementitious matrix
url https://www.mdpi.com/2075-5309/14/9/2762
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