Micro/meso scales characterization of alkali-activated fly ash-slag concrete under sustained high-temperatures with X-CT, MIP, and SEM tests
File(s)
Accepted version
Author(s)
Type
Journal Article
Abstract
Based on X-CT, MIP, and SEM tests, the micro/meso scales evolutions of alkali-activated fly ash-slag (AAFS) concrete under sustained high temperatures are studied. The results show that the water loss of the C–S–H and C-A-S-H gel phases at 60 °C is continuous (about 60d). The variation law of meso-scale pore volume based on the X-CT test is consistent with that of micro-scale pore volume obtained by the MIP test. The 2D fractal dimension can be used to qualitatively evaluate the internal micro-cracks and microstructure complexity of AAFS concrete after sustained high-temperature action. The mass loss rate can reach stability within 3d-7d under the action of 100 °C, 150 °C, and 200 °C, and there is no cumulative effect of micro-cracks and pores caused by initial water loss. Under sustained high-temperatures, the internal pore structure, micro-cracks, and microstructure changes of AAFS concrete are persistent, and these persistent changes lead to a significant change in the mechanical properties of AAFS concrete.
Date Issued
2024-12
Date Acceptance
2024-10-27
Citation
Materials Today Sustainability, 2024, 28
ISSN
2589-2347
Publisher
Elsevier BV
Journal / Book Title
Materials Today Sustainability
Volume
28
Copyright Statement
Copyright © 2024 Elsevier Ltd. This is the author’s accepted manuscript made available under a CC-BY licence in accordance with Imperial’s Research Publications Open Access policy (www.imperial.ac.uk/oa-policy)
License URL
Identifier
https://doi.org/10.1016/j.mtsust.2024.101036
Publication Status
Published
Article Number
101036
Date Publish Online
2024-11-01