THE GREEN COMPRESSION STRENGTH OF NATURAL BENTONITES 1 By

Cored specimens of several commercial bentonite beds were preserved at field moisture levels for laboratory examination. Green strength, water content, and x-ray diffraction character of undisturbed material were found to conform substantially to the relation that strength is proportional to the solid fraction. The remarkable unidimensional swelling properties of bentonites have led to many extended studies of their water sorption characteristics a laboratory proc-esses. In general these procedures are applied to prepared commercial products or to indefinitely aged mineralogical specimens. Several years ago a unique opportunity was presented the author, through the offices of Dr. R. E. Grim, to study a set of ten specimens from bentonite beds being exploited by the Baroid Division of the National Lead Company. Care was taken to preserve the field water content, and the specimens were delivered sealed and undisturbed for laboratory analysis. They were received at the peak of the characteristic high relative humidity of midsummer, permitting testin