Suggestions for Test Methods...

[mikeofBelAir]

Having secured our Accreditation for Concrete testing, I am now starting the process for SOILS. We do not require accreditation in a great number of Standards, just basic Identification and Moisture-Density should be sufficient.
I will pursue both ASTM and AASHTO methods for proctors as both are cited in many job Contracts.
Otherwise, I think we will stick with ASTM for Sieves, Hydrometers and Limits.
My question ( besides general advice) is what is the best (easiest) method for Specific Gravity of Soils? What I know of the ASTM method seems unnecessarily complex, and tedious. Is there a better method? What do you all use?

 

[oldestguy]

I'm curious. Will you folks also be doing field sampling and testing? If not and only doing lab testing, I'd not expect much work coming in.

 

[Ron]

Mike...I'd rather guess the specific gravity based on the soil type than run the tests!

Unfortunately, for accreditation, you'll need the capability to run at least the water pycnometer version for soils. If you're in an area where the soils might contain a lot of organics or have constituents that would be dissolved or go into solution during the test (calcareous silts for example), you'll probably need the gas pycnometer method as well.

Other than that, the procedure for concrete fine aggregate is simpler and probably as accurate as any. I've never considered the specific gravity test to be as accurate as the significant figures would imply!

 

[mikeofBelAir]

Ron, my sentiments exactly. Just because we can calculate to 3 or 4 or 50 digits doesn't mean that "information" is of any value. The very next scoop of soil will be different. When I first learned Proctors, the standards merely required that the blows from the rammer be equally distributed across the surface of the soil. Now we have a prescribed pattern that MUST be followed. Too many people "trying to make a difference".....
Hey, you kids----get off my lawn"
Yes I am the curmudgeon.
I have decided, to use the AASHTO T100 standard for Specific Gravity.

Yes--OldestGuy--we will also be doing field testing, but so far, none of our clients require accreditation for density testing.

 

[mikeofBelAir]

Another question.....
I have been running D422 ( Gradation with hydrometer) for years. Sometimes w/o the hydro, which I understand means that the test was not run according to the Standard, as the hydrometer portion was not optional, even though it was often treated that way.
I see they have broken out the sieves only portion of the test and issued it as ASTM D 6913.
I also see a new Gradation with hydrometer issued as ASTM D7928
Further....AASHTO still certifies under the old ASTM D422 Standard.

Now the questions...
Do any of you have experience with the newer standards ( D6913 or D7928) and care to share your opinion? My volume of the ASTM soils doesn't include those numbers, so I will have to purchase them separately, if I need them, so I am asking for opinions as to whether I should just go ahead and get them. My guess is that eventually the AASHTO inspectors will require them and not accept D422.
Are there any major differences with the new specs? Any surprises?

Thanks

 

[SoiloftheMonth]

Mike
I read ASTM is working on a standard that combines sieve and hydrometer, see here.

 

[fattdad]

D422 is withdrawn.
D2487 is needed to actually classify soils.
Get the specific gravity certification!
How about extracting tubes?
Density?

There is also the R18 certification? Google it? I think I got that right?

f-d

ípapß gordo ainÆt no madre flaca!