This investigation evaluates the influence of various curing conditions and slag inclusion on the fresh, mechanical, and durability properties of self-compacting geopolymer concrete (SCGC) based on fly ash (FA). Curing temperature and curing time have a vital role in the strength and microstructure of geopolymer concrete. Therefore, to begin the research, the impacts of different curing conditions (curing temperature and curing time) and slag content on the compressive strength of FA-based SCGC were examined to determine the optimum curing method. A series of four SCGC mixes with a fixed binder content (450 kg/m) and an alkaline/binder ratio of 0.5 was designated to conduct a parametric study. FA was replaced with slag at four different substitution percentages, including 0%, 30%, 50%, and 100% of the total weight of the binder. The fresh properties of the produced SCGC specimens were investigated in terms of slump flow diameter, T50 flow time, and L-box height ratio. Additionally, the following mechanical properties of SCGC specimens were investigated: modulus of elasticity and fracture parameters. The water permeability and freezing-thawing resistance were studied to determine the durability behavior of SCGC. In this study, the optimum curing temperature was 85 °C for the duration of 24 h, which provided the maximum compressive strength. The results confirmed that adding slag affected the workability of SCGC mixtures. However, the mechanical characteristics, fracture parameters, and durability performance of SCGC were improved for slag-rich mixtures. When using 50% slag instead of FA, the percentage increase in compressive, flexural, elastic module, and fracture energy test values were about 100%, 43%, 58%, and 55%, respectively, whilst the percentage decrease in water permeability was 65% and the resistance to freeze-thaw test in terms of surface scaling was enhanced by 79%.
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http://dx.doi.org/10.3390/polym14153209 | DOI Listing |
Sci Rep
January 2025
School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang, 471000, China.
Geopolymer concrete (GC) is green and environmentally friendly. In order to comprehensively study the mechanical properties and influence mechanism of geopolymer concrete-filled steel tubular (GCFST) columns under various working conditions, this study takes the strength grade of geopolymer concrete, length-diameter ratio and wall thickness of steel tube as design parameters. Eight GCFST columns are designed and the compressive performances are conducted under repeated axial compression.
View Article and Find Full Text PDFMaterials (Basel)
December 2024
School of Engineering, Computing and Mathematics, University of Plymouth, Plymouth PL4 8AA, UK.
Geopolymer concrete is a sustainable construction material and is considered as a promising alternative to traditional Portland cement concrete. However, there is still not much research on the effective properties and damage behavior of geopolymer concrete with consideration of its heterogeneous characteristics by means of mesoscale models combined with the regularized microplane damage model. Here, in this research, an easy and simpler approach for generating concrete mesoscale models and characterizing the angular characteristics of aggregate particles is presented.
View Article and Find Full Text PDFNat Commun
January 2025
Chair of Sustainable Construction, Institute of Construction and Infrastructure Management (IBI), ETH Zürich, Stefano-Franscini-Platz 5, 8093, Zurich, Switzerland.
Indoor humidity can significantly impact our comfort and well-being, often leading to the use of mechanical systems for its management. However, these systems can result in substantial carbon emissions and energy precarity. This study offers an alternative: using low-carbon materials that naturally buffer moisture to passively regulate the indoor humidity.
View Article and Find Full Text PDFMaterials (Basel)
December 2024
Faculty of Materials Engineering and Physics, Cracow University of Technology, Jana Pawła II 37, 31-864 Cracow, Poland.
Geopolymer materials are increasingly being considered as an alternative to environmentally damaging concrete based on Portland cement. The presented work analyzed waste from mines and waste incineration plants as potential precursors for producing geopolymer materials that could be used to make lightweight foamed geopolymers for insulation applications. The chemical and phase composition, radioactivity properties, and leachability of selected precursors were analyzed.
View Article and Find Full Text PDFEnviron Res
January 2025
School of Materials Science and Engineering, Fuzhou University, Fuzhou, Fujian, 350108, China; Zijin School of Geology and Mining, Fuzhou University, Fuzhou, Fujian, 350108, China; Fujian Key Laboratory of Green Extraction and High-value Utilization of Energy Metals, Fuzhou University, Fuzhou, Fujian 350108, China.
In this study, combination of wave absorption materials with different loss mechanisms are added into iron ore tailings-blast furnace slag (IOT-BFS) based geopolymers. The employed materials are hollow glass microsphere (HGM), carbon nanotubes (CNT) and carbonyl iron powder (CIP). Microstructures of the geopolymers are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and concrete porous structure analyzer.
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