Compressibility and Collapsibility Characteristics of Sedimented Fly Ash Beds
Publication: Journal of Materials in Civil Engineering
Volume 20, Issue 6
Abstract
The fly ash produced from thermal power plants (TPP) is disposed of in the form of slurry into ash ponds, lagoons, or dykes. Fly ash slurry, after undergoing sedimentation and consolidation processes under its own self-weight, exhibits a different engineering behavior than those compacted after dewatering. Literature review indicated no studies are available on the engineering behavior of sedimented fly ash beds/deposits, which is impeding the recycling efforts of the sedimented fly ash beds/deposits. This paper presents test results from laboratory studies conducted on sedimented fly ash deposits prepared by simulating both natural sedimentation and consolidation processes in a prototype environment. A series of compressibility, consolidation and collapse tests were then conducted on specimens collected from the sediment deposits. Test results revealed that the sedimented fly ash material exhibits a pseudoover consolidation effect including a moderate collapsible behavior and an increased compressibility at applied stresses. Collapse potential of the materials ranged between 0.5 and 1%, indicating a metastable fabric of these materials formed in the sedimentation process. Potential engineering behavioral issues related to recycling efforts of fly ash beds are mentioned.
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Acknowledgments
This study was supported by the Central Building Research Institute (CBRI), Roorkee, India. The writers, would like to acknowledge this support. Also, they would like to acknowledge Panki Power Plant for providing material support.
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Information & Authors
Information
Published In
Journal of Materials in Civil Engineering
Volume 20 • Issue 6 • June 2008
Pages: 401 - 409
Copyright
© 2008 ASCE.
History
Received: May 18, 2006
Accepted: Nov 28, 2007
Published online: Jun 1, 2008
Published in print: Jun 2008
Notes
Note. Associate Editor: Jason Weiss
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