Type of Clay from Atterberg limits

[bigfoot17]

Does anyone know a very simplified approach to determining the type of clay (kaolinite, illite, mont., etc.) from Atterberg limits. I have a plot of the A-line with the different types shown, but was looking for a more precise way to plug into a spread sheet, I have 1000+ samples and did not want to use a graph for each one, thanks.

 

[CarlB]

If those clay types have specific PI & LL ranges, which would follow if they are depicted on an A-line graph, then yes you can write a formula to convert Atterberg test results to clay type. I would think there are regions of overlap, but you could have the formula return a dual identification.

 

[ashjun]

Hi,
To evaluate the time of clay can I presume you are interested in the swelling potential. You need one more parameter in addition to the atternerg limits - which is the percentage clay content.

Do a quick search on activity (defined as plasticity index divided by the percentage clay content). Activity more than 1.25 means expansive clay and less than 0.75 is considered as in active.

Rgds