Atterberg Limits for Peat or Organic Soils

[ditapark]

Hello. So I'm about to do a several tests for the peat soils and one of them is atterberg limits. So I wondering should we dry the soil overnight in the oven before we do the test or just do the test without drying it? Is there any special treatment or method we should do when we're doing the atterberg limits test for the peat soils? And my soil condition is disturbed soil. Thank you.

 

[Ron]

Not sure you'll get much useful info from the Atterberg limits unless you have that relatively rare bird of a plastic silt.

As for running the test, don't dry the sample before you do the the test. You have two moisture content break points in the test and to dry with sample before the test is a waste of time and could affect the results.

Just from a moisture content, percent fines and organic content you can properly characterize the soil without Atterberg limits.

 

[GeoPaveTraffic]

If the material is truly organic, then all you are really going to do is measure the organic content.

Atterburg limits are for clays and silts, not organic soils.

Mike Lambert

 

[GeoPaveTraffic]

To Ron, while plastic silts are rare in some areas, in other areas they are very common. For us a non-plastic silt is the rare one.

Mike Lambert

 

[Ron]

Mike...you are correct. It isn't rare in some areas!

 

[oldestguy]

For organic content, "loss on ignition" is very useful. A necessary test for peat, for sure.

 

[ditapark]

Thank you guys!!

 

[fattdad]

Atterberg limits are the only basis to define organic silt and organic clay of high or low plasticity. They are required to define certain organic soils. When considering the minus 40-size materials of a peat, the test would certainly return some value.

We see OH and OL soils in the Coastal Plain regularly and I will not accept a non-ASTM visual classification on either. I also will not accept loss on ignition in lieu of ASTM testing.

Not to take away from other replies. Just saying check ASTM D-3487 if that's your standard for soil classification.

f-d

ípapß gordo ainÆt no madre flaca!