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Basic question regarding compaction

Basic question regarding compaction

(OP)
Hi, we work on solidification of liquid waste, and we are looking for potential ways of using our solidified material. We get asked about the compactibility of our material very often, but I do not have expertise in this field and was hoping to get some help. The material that we end up with is not like a soil where you can dry it, add moisture back, and do a proctor test. The material that we have would form clumps when dried. and it does not rehydrate like a soil would. This solidified material will pass paint filter test and is typically landfilled, but it would be great if we can use it as backfill or something so that it's not going to waste. We have another reagent that can turn the liquid waste into a paste like material (like working cement) and becomes hard after it dries. However, I don't know what specs there are to allow us to use this material for other purposes. For example, would it be helpful if we tested the compression strength and said "our material, once dried, can withstand a compression force of X PSI"?
Anyway, I may not have been super clear with my question, but any advice and further discussion would be greatly appreciated!

RE: Basic question regarding compaction

Is there a chance that any hazardous leachate or air born material is possible?

RE: Basic question regarding compaction

(OP)
We mainly deal with solidifying drilling mud, and there are typically nothing toxic or hazardous coming out of that material. After our treatment, there is minimal leaching and nothing air born.

RE: Basic question regarding compaction

If you can make a paste with the material, you can mold a compressive strength specimen and have it tested. I would suggest either 3"x6" cylinders or 2" cube molds.

RE: Basic question regarding compaction

(OP)
So I thought about doing that, but what is the spec that I would test? Would I just make the slab and then use a force gauge to test how many PSI it would take to crush the sample? Are there standard specs out there that says the dried material must meet X to be used for some purpose? Also, what about using the material as backfill or something? How could I test for that? We have different reagents that will produce materials that's very different in characteristic. Ideally, we would be able to just treat the waste drill mud with whichever reagent that's appropriate for the end use purpose.

RE: Basic question regarding compaction

metaflo....yes, there are unconfined compressive strength requirements for various soil applications. One use that I could think of for this material is as a form of "flowable fill" or "controlled low strength material". You might have to add a little portland cement to increase the strength for some applications.

You will also need to check for shrinkage and for swelling. Both are important parameters for soils and fill materials.

You don't need to make a slab of the material. Call a local materials testing lab and let them mold the samples and do the tests. They are not that expensive and for a few hundred dollars you can get a lot of data.

RE: Basic question regarding compaction

(OP)
Thanks Ron! I'm just having trouble finding out what the exact specs are... they seem to be difficult to find online. So our main product that we have produces a material that is similar in feel to top soil; however, I don't know how I would perform a proctor test on it, because it doesn't dry like soil would. I guess another confusion I have is what's the difference between this compression test for these "flowable fills" and the proctor test for soils? Can both be used to test the same material? I've attached a picture of the main solidified material that we work with, the most basic question for me is "what can we do with this material other than landfilling it?"

RE: Basic question regarding compaction

you could try California Bearing Ratio testing and reposting with data

RE: Basic question regarding compaction

metaflo,

A proctor is performed to help determine the relationship between % moisture vs. density, thus telling you the maximum compaction.

The compression test is performed to tell you the strength (psi) of the material. You can perform multiple samples at different moisture levels to help determine the compressive strength of the material. As mentioned earlier, you can see what amount of Portland cement it takes to increase the strength to the desired levels.

The procedures for each test a spelled out from ASTM. As for the desired strengths you are looking for that is determined by project needs.

I can't really speak on strength requirements, but for a lot of slabs and structures 4,000 psi is a good level to aim for. As for use a fills it would mostly come down to cost (cost of your stuff vs. cost of borrow fill).

--morgwreck243

RE: Basic question regarding compaction

morgwreck243 has his units mixed up. You'll never find a soil with "bearing" of 4000 psi (576,000 psf or 288 tsf). I am sure he means 4000 psf. (A problem with civil/structural vs geotechs)

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