Accurate determination of the 'time-zero' of autogenous shrinkage in alkali-activated fly ash/slag system
Article
Article Title | Accurate determination of the 'time-zero' of autogenous shrinkage in alkali-activated fly ash/slag system |
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ERA Journal ID | 4883 |
Article Category | Article |
Authors | Ma, Y. (Author), Yang, X. (Author), Hu, J. (Author), Zhang, Z. (Author) and Wang, H. (Author) |
Journal Title | Composites Part B: Engineering |
Journal Citation | 177, pp. 1-8 |
Article Number | 107367 |
Number of Pages | 8 |
Year | 2019 |
Publisher | Elsevier |
Place of Publication | United Kingdom |
ISSN | 1359-8368 |
Digital Object Identifier (DOI) | https://doi.org/10.1016/j.compositesb.2019.107367 |
Web Address (URL) | https://www.sciencedirect.com/science/article/abs/pii/S1359836819320633 |
Abstract | Autogenous shrinkage based on different 'time-zero' may result in underestimation/overestimation on the cracking potential of alkali-activated fly ash/slag (AAFS). This study reports an experimental investigation on the 'time-zero' of AAFS pastes characterized by different techniques. It is found that the internal capillary pressure in AAFS pastes significantly increased after 5–7.5 h, which is far beyond the final setting time that is normally regarded as 'time-zero' for Portland cement. The transition time derived from capillary pressure method directly captures the alteration of capillary stress in AAFS, which matches well with the change of the shrinkage slope. Due to the moisture equilibrium between the specimens and humidity sensor, it is hard to use the measured internal relative humidity to determine the real 'time-zero' of AAFS. This research finds that the onset of capillary pressure in AAFS paste provides a more scientific and accurate determination of 'time-zero'. |
Keywords | autogenous shrinkage, time-zero, capillary pressure, internal RH, alkali-activated fly ash/slag |
ANZSRC Field of Research 2020 | 400505. Construction materials |
Byline Affiliations | Centre for Future Materials |
Guangzhou University, China | |
South China University of Technology, China | |
Institution of Origin | University of Southern Queensland |
Funding source | Australian Research Council (ARC) Grant ID 1006016 |
https://research.usq.edu.au/item/q592z/accurate-determination-of-the-time-zero-of-autogenous-shrinkage-in-alkali-activated-fly-ash-slag-system
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