Capillary Shape: Influence on Water Transport within Unsaturated Alkali Activated Slag Concrete
Publication: Journal of Materials in Civil Engineering
Volume 22, Issue 3
Abstract
Cementitious binders consisting of ground granulated iron slag and an alkaline activator (alkali activated slag) have considerable environmental benefits when used as an alternative to conventional 100% ordinary portland cement binders. The objective of this paper is to demonstrate the effect of pore cross section shape on unsaturated flow and to contrast the laboratory and numerical predictions of alkali activated slag binders and 100% portland cement binders. Convection-based uptake of water within capillary pores is modeled using pore size distribution data; however, most existing predictive models are based on the assumption of a circular cross section. This model allows for changeable capillary cross-sectional shape by employing ellipses ranging in shape from circular to slit. By applying a shape factor that accounts for departure from circularity of the pore cross section, the prediction model shows reasonable agreement with water sorptivity test data. As well as different binder types, the predictive model is assessed over a range of concrete ages and curing conditions.
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Acknowledgments
The financial support for this project is jointly provided by Independent Cement and Lime Pty Ltd, Blue Circle Southern Cement Ltd, and Australian Steel Mill Services. The writers thank the sponsors especially Alan Dow, Tom Wauer, Katherine Turner, Paul Ratcliff, John Ashby, and Dr. Ihor Hinczak for the guidance and support. The enthusiastic participation of final year students Soon Keat Lim and Eric Tan in this project is very much appreciated. The efforts and assistance with the laboratory work provided by Jeff Doddrell, Roger Doulis, and Peter Dunbar are also gratefully acknowledged.
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Information & Authors
Information
Published In
Journal of Materials in Civil Engineering
Volume 22 • Issue 3 • March 2010
Pages: 260 - 266
Copyright
© 2010 ASCE.
History
Received: Apr 21, 2008
Accepted: Oct 21, 2009
Published online: Feb 12, 2010
Published in print: Mar 2010
Notes
Note. Associate Editor: Christopher K. Y. Leung
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