Textural and microstructural influences on the durability of Waikato Coal Measures mudrocks
Authors:
- 1 August 1995
- journal article
- Published by Geological Society of London in Quarterly Journal of Engineering Geology
- Vol. 28 (3) , 303-312
Abstract
Data on durability, petrography and microstructure are presented for 27 specimens of Waikato Coal Measures mudrocks: fine-grained, carbonaceous rocks, which are dominated by kaolinite clays, and have low durabilities. The poor durability is not caused by swelling clays. Rather, slaking is believed to result from the release of residual stresses within the rock following weakening by water adsorption on to clay surfaces and a consequent loss in cohesiveness. This mechanism favours fragmentation into small, water-stable fragments, rather than dispersion of clays into the water. The amount of day-sized material in the rocks provides the most direct control on the durability, but mierostructural features are also recognized as important: specimens with a discontinuous matrix have a slightly lower durability than those with a continuous matrix.Keywords
This publication has 12 references indexed in Scilit:
- Lithological controls of mudrock durabilityQuarterly Journal of Engineering Geology, 1992
- Engineering description of mudrocksQuarterly Journal of Engineering Geology, 1992
- Influence of microfabric on geomechanical behaviour of tertiary finegrained sedimentary rocks from Central North Island, New ZealandBulletin of Engineering Geology and the Environment, 1988
- Ponui Landslide: A deep‐seated wedge failure in Tertiary weak‐rock flysch, Southern Hawke's Bay, New ZealandNew Zealand Journal of Geology and Geophysics, 1987
- Waipoapoa Landslide: A deep‐seated complex block slide in Tertiary weak‐rock flysch, Southern Hawke's Bay, New ZealandNew Zealand Journal of Geology and Geophysics, 1987
- The engineering geology of clay minerals: swelling, shrinking and mudrock breakdownClay Minerals, 1986
- The classification of mudrocks for engineering purposesQuarterly Journal of Engineering Geology, 1984
- The form and function of microfabric features in a variety of natural soilsGéotechnique, 1974
- Detrital sedimentary rock classification and nomenclature for use in New ZealandNew Zealand Journal of Geology and Geophysics, 1970
- Te Kuiti groupNew Zealand Journal of Geology and Geophysics, 1959