Proctor Testing for Course Soils
Proctor Testing for Course Soils
(OP)
We have a site design for a proctor to be taken per the ASTM D-1557 method. The gradation report came back showing soils that are too course to run the proctor.
Is there a method to perform a proctor with course soils? Is there a way to write a specification to control the soils so a sensible / cost effective proctor can be done?
Is there a method to perform a proctor with course soils? Is there a way to write a specification to control the soils so a sensible / cost effective proctor can be done?





RE: Proctor Testing for Course Soils
It's all weight and volume relationship stuff (and simple math).
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¡papá gordo ain't no madre flaca!
RE: Proctor Testing for Course Soils
RE: Proctor Testing for Course Soils
If you ran it dry, I would try running it again iver a washed, sometimes fines can clump up with other particles and cause a 1/2" to be retained on a 3/4". Not often, but it can happen, especially if it is a silty material.
Unfortunately, according to D1557, there is no other ASTM which can accomodate for more than 30% retained on the 3/4" sieve.
Another way to go about this could be to call for processed 1/2" or 3/4" material in accordance with certain DOT specs. You would get a more granualted material, it's easy to have a proctor run on the material, and the overall cost really wouldn't be that much greater, at least in my experience.
RE: Proctor Testing for Course Soils
WSDOT has a test method #606 that is used to determine density and mositure content for materials over 30% that we are going to use.
You dont think that would be expensive to spec that material can not be greater then 1/2" or 3/4"?
RE: Proctor Testing for Course Soils
Dry sieve vs. washed sieve is really an opinion stance. Certain engineers like the washed sieve so they can determine the actual amount of fines in the material, but an added bonus is that it provides a "cleaner" sieve of the material (and just may knock your 3/4" retained to under 30%). I would recommend reading up on ASTM D422 for washed sieves.
As an added note, you may just be able to argue your case to use D1557 yet. If you read section 5.3.1 of D1557 closely, it says "soils containing more than 30% oversize fraction...are a problem." So if you're right at 30.00%, you could try to argue that you can use D1557 to determine your proctor.
Finally, you could try D4914 or D5030, which could determine "field" dry unit weights. However, the downside to these two methods are they're not widely used and they're rather costly.
RE: Proctor Testing for Course Soils
Thanks for the info, very helpful.
RE: Proctor Testing for Course Soils
For your question regarding test method, yes...the process is called scalping where the Proctor sample is run dry, usually by hand, through a 3/4" scalping screen. The retained material is weighed to get the proportion.
For a grain size distribution, it is usually an extra procedure to run a large enough sample through a short nest of sieves for a wash 200 test, then do full distribution on the sample after drying.
RE: Proctor Testing for Course Soils
RE: Proctor Testing for Course Soils
RE: Proctor Testing for Course Soils
RE: Proctor Testing for Course Soils
RE: Proctor Testing for Course Soils
I think we are diving too far into this with the balloon methods and whatnot. Its a simple 4' max. pit run fill for an asphalt parking structure. Specs call for maximum particle size of 6" with max. lift of 1'. Would not make sense to ask them to make the particle size 3/4", nor is it good engineering practice.
I have not run into the situation much where the fill material comes back too coarse to run the D1557 method so I was just looking for feedback on how this is normally handled. I know one way I have heard of it being handled before is, as the lifts are completed to do a proof roll without testing. This can be subjective and takes a very experience inspector and contractor. Personally, I would feel uncomfortable with this method if buildings were going to be place on top of this fill.
RE: Proctor Testing for Course Soils
ICC special inspector, Structural masonry, Reinforced concrete.
RE: Proctor Testing for Course Soils