Publication Date:
1988-11-01
Description:
A laboratory test program was undertaken to assess the effects of various ionic surfactants on the mechanical and hydric properties of a kaolinite. The tests showed that surfactants, particularly the cationic species, significantly modified the properties of the unsaturated clay (water absorption rate, absorbed water quantity, suction, swelling, etc.); however, the behaviour of the saturated soil was hardly changed. These results were correlated with measurements of the wettability characteristics of thin plates of consolidated clay. An original method, based on the concept of unit work of dewetting, was used to measure the solid – liquid – gas contact angle of the porous and rugose substrate. In the case of the kaolinite mixed with the cationic surfactant, the contact angle reaches 90° (instead of the 49° for the reference system), corresponding to a significant decrease in the soil suction. Such a decrease can explain the results obtained during infiltration and swelling tests. Key words: surfactants, wettability, unsaturated clays, suction.
Print ISSN:
0008-3674
Electronic ISSN:
1208-6010
Topics:
Geosciences
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