drying temperature for atterberg limits determination of montmorilloni

[tonette]

Hi! If my clay is basically montmorillonite or illite clay, can I still use the standard 105 oC drying temperature for atterberg limits determination? Wouldn't this temeparature be too high such that montmorillonite/illite structure already breakdown?

 

[Ron]

For this clay and the because of the sensitivity of the test, I would dry in a dessicator, not an oven.

 

[BigH]

I apologise that I don't have the book in front of me, but check out, if you can find it, Zeevaert's book on "Foundations on Difficult Soils". As he deals with Mexico City clay, I vaguely remember that he had some comments on this particular aspect. I don't think that illite would be a problem; montmorillonite and bentonite might be due to the driving off of "attached" water.