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Chemical Relationships Affecting the Water‐Holding Capacities of Clays
Author(s) -
Thomas Grant W.,
Moody John E.
Publication year - 1962
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1962.03615995002600020017x
Subject(s) - bentonite , kaolinite , montmorillonite , clay minerals , saturation (graph theory) , expansive clay , geology , mineralogy , water saturation , chemistry , soil water , soil science , geotechnical engineering , mathematics , porosity , organic chemistry , combinatorics
The relation between water‐holding capacity and clay properties was studied on Wyoming bentonite and four Virginia soil clays ranging in mineralogical type from montmorillonite to kaolinite. The amount of water held at 1/3 atm. pressure was closely related to clay type and cation saturation; the Na‐montmorillonites containing much more water than any other clays. At 15‐atm. pressure there was little difference in water held between any of the clays regardless of cation saturation or clay type. The only exception was Na‐bentonite which held 71% H 2 O compared to a mean of 48.6 ± 3.2% among all the other clays. Analyses of displaced solutions from the clay suspensions showed that only in Na‐montmorillonites was the predicted double‐layer pattern of reduced anion concentration at lower water contents followed. This and the fact that other clays apparently did not imbibe much water between layers support the idea that the double‐layer theory is applicable only to freely‐expandable clay minerals.