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Water Content and Bulk Density During Wetting of a Bentonite‐Silt Column
Author(s) -
Nofziger D. L.,
Swartzendruber D.
Publication year - 1976
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/sssaj1976.03615995004000030014x
Subject(s) - silt , bentonite , water content , wetting , inlet , saturation (graph theory) , bulk density , soil science , water column , mineralogy , geology , materials science , soil water , geotechnical engineering , composite material , mathematics , paleontology , combinatorics , geomorphology , oceanography
An improved method of dual‐energy gamma‐ray attenuation was used to measure water content and bulk density rapidly and accurately, during one‐dimensional, unsaturated water movement into a column of an equal‐part mixture of initially air‐dry, highly swelling bentonite and silt. The bulk density near the inlet end of the column decreased rapidly as water entered. Since the ends of the column were confined, the expansion of the wetted bentonite‐silt produced a compensating compression in the remaining air‐dry portion of the column. Several water‐content variables were plotted against the so‐called reduced material coordinate m/t 1/2 (Boltzmann variable expressed in terms of the material coordinate m and time t ). Neither the volumetric water content nor the volumetric water ratio would coalesce the data when plotted against m/t 1/2 . In contrast, a plot of water saturation vs. m/t 1/2 did coalesce the data into a single curve, except for very early times at positions nearer than 1 cm to the water inlet.