Title
Lithofacies and petrophysical properties of Portland Base Bed and Portland Whit Bed limestone as related to durability
Author
TNO Bouw
Dubelaar, C.W.
Engering, S.
van Hees, R.P.J.
Koch, R.
Lorenz, H.G.
Publication year
2003
Abstract
This study focuses on the differences in lithofacies and petrophysical properties of Base Bed and Whit Bed Portland limestone and the presumed relationships between these characteristics and the durability of this building stone. As Portland limestone probably will be used as a stone for several restoration projects in the Netherlands in the near future, it is of great importance to know the weathering behaviour, especially its resistance against freezelthaw decay. Samples of Portland limestone were analyzed by means of thin section microscopy, X-Ray fluorescence spectroscopy, and measurements of petrophysical properties such as watersaturation, porosity, permeability and specific surface area. Distribution of pore throat diameters were analyzed by mercury porosimetry. Results of a freeze/thaw test performed on Whit Bed limestone were also taken in account. The Whit Bed consists of a medium grained, fine to coarse bioclastic oolitic limestone (oobiosparite; oolitic grainstone). Generally the fabric is grain supported showing a large amount of open inter-particle pores. High effective porosity combined with high permeability (1000 - 1400 milliDarcy), predominantly reflect the open interparticle porosity. The Base Bed is also a coarse bioclastic oolitic grainstone, but the oolitic fabric shows a tighter, matrix-rich compacted texture. Samples from the Base Bed show differences in primary matrix contents compared to the Whit Bed and differences in diagenesis, resulting in different physical propefties. For example, a lower effective porosity (15.11 - 15.99 vol.%) and a lower permeability (35.0 - 80.1 milliDarcy). It is concluded that a thorough study of lithofacies (especially microfacies) and analysis of microporosity reveal basic data for selecting the most durable type of limestone. In this particular case, using only samples from one quarry, the Whit Bed samples are thought to be the most durable ones.
Subject
Building stone
Portland limestone
Base bed
White bed
Lithofacies
Microfacies
Durability
Freeze/thaw decay
Microscopy
Mercury intrusion porosimetry
Buildings and Infrastructure
Built Environment
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http://resolver.tudelft.nl/uuid:d440cda3-7798-4349-88e2-02a4e3a29198
TNO identifier
330677
Source
Heron, 48 (48), 221-229
Bibliographical note
Special issue verschenen in mei 2004
Document type
article