Soil Density With Just a Roller 3

[Chaddar]

When I received my WAQTC qualification in the class they had mentioned you could find the proctor with your nuke by making 10 passes over a certain square footage is this true? I am waiting for my lab to show up so I can pound a proctor but the super is curious now about the density of the borrow.

Thanks,
/cs

 

[eekgec]

yes, as an approximation you can have the contractor roll/compact the area many, many times. If you take a density test after each pass of the compactor, you should see the density climb and then level off, when it levels off, this could be assumed to be the maximum density of the material.

this is only a field approximation however, it may or may not match your laboratory proctor.

 

[Chaddar]

How do you determine what proctor to start at?

 

[GeoPaveTraffic]

You don't "start at" any Proctor. What eekgec is saying is that you measure the density, not the percent compaction. Since you are not using the percent compaction function of the nuke gauge you can put any Proctor value into the machine that you want.

That said, I disagree with eekgec. Rolling with a specific roller at a given water content until the density no longer increases will give you a maximum density. If you changed the water content or the size of the roller, you would get a different maximum dinsity. It is very unlikely that either of these maximums will be the maximum as determined by either the standard or modified Proctor test.

If you really wanted to determine the maximum Proctor density, for either the standard or modified test, you would need to match the roller energy to that used by the specific test method. Then you would need to varry the moisture content while applying that energy.

In other words, wait on the lab test.

 

[fattdad]

+1 to GTP's excellent post!

¡papá gordo ain’t no madre flaca!

 

[Ron]

GPT is exactly right...wait on the lab test, otherwise you have nothing standardized nor defensible that you can check against.

What you are doing is combining a rolling procedure with density testing, but you'll never know what you've actually achieved with respect to what it could or should be.

You'll be using a piece of expensive equipment and the labor of several people, the time to do the density testing, the equipment to do the density testing....all compared to $150 lab test that will give you the proper comparison answer, not some half-assed guess.

 

[BigH]

No question, lab testing is "the way to go" - but sometimes, small jobs . . . Search for some other posts where I have described the Ontario Ministry of Transportation's "old" method of field and estimated proctor comparison. A bit time consuming for a test (about 45 minutes) but is good for the small jobs and jobs where the material changes might render the lab proctor a bit dicey anyway.

 

[Chaddar]

I know a lab is the way to go like I said lab is not here yet and is about a week out was just curious about getting a rough idea nothing that will be going into any report as a valid test. I think I got some clarification what I remember was for HMA with a roller not on soils it appears. Thanks you all for the responses.

 

[bb29510]

yes he right. take a test after each roll till it goes to pumping from increse moisture. graph each density and moisture. that your pd curve. the highest lbs per cu ft your proctot

 

[GeoPaveTraffic]

brownbagg,

What you are describing will not generate a Proctor curve. It will generate a moisture / density curve, but not all moisture / density curves are Proctor curves.

A Proctor requires a specific amount of energy be applied to compact the sample in a specified maner. ONLY by doing that can you generate a Proector cureve for a material. There are two Proctor mehtods and they are different in the amount of energy used to compact the material.

Also note that Proctor should be capitalized since the test methods are named for a person.

 

[bb29510]

yes I know, the proctor name would not be the best term, It just what we call the test. Yes its not a standard(roller), Its not astm but the prinicpal would show you the property of that type soil. If you assume that the Modified Proctor is the ultimate curve, using a heavy roller should produce a curve that be close to the lab work. The question was waiting on a lab. It not standard but it would give you an idea