Is there a Standard for "No. 2 Crusher Runö?

[aeroUB]

I'm working on a job here and for the foundation of our basin we have specified "95% compacted No. 2 Crusher Run"

The customers QC department has come back and want some kind of spec. or ASTM # that actually specifies WHAT No. 2 Crusher Run is...what standards it has to meet to actually be No. 2 crusher run.

Does anyone know of a standard or spec. that would define what they want to know?

Thanks a lot
Ken

 

[cvg]

I would call your local material supplier and ask them to send you the most recent test report for the stockpile. Use that for your spec.

 

[TerraSouth]

"Crusher run" has no spec that I'm aware of. It is simply ungraded crushed stone straight from the crusher. I've never heard of "crusher run" being specified on any project.

You need to spec a graded crushed stone. Check out your Highway Department specifications and choose a crushed stone.

 

[cvg]

If the purpose of the stone is simply to line the bottom of a basin, you probably don't need to spec a graded stone. The crusher run would probably be fine and might be cheaper. But, you still need to provide some sort of specification to the contractor so you know what you are getting. At a minimum you might want to restrict the maximum particle size or the amount of fines. Ask your supplier for a sample of his crushed rock - from the stockpile.

However, if you are using it for base material under structures, you may want to evaluate the properties of the material to see if it will meet your needs.

 

[LHA]

I agree with Terrasouth, the term "crusher run" means ungraded "stuff" (my term, for lack of a better one) right of the chute. In the northeast of the USA, you will also hear "bank run" and "bank run gravel" used synonymously.

But I disagree with Terrasouth, a graded aggregate is not always needed, and if you are talking about the bottom of an unlined stormwater management basin, the material is almost never spec'd - unless filtration is required, then it must be.

Typically, I write "suitable fill" and "unsuitable fill" into specs. This material applies to areas where structural characteristics and contact with U/G utilities are not of concern...like the bottom of a basin, for example.

Suitable fill is simply dirt, with some general qualifiers: 0% over 2" stone within 24" of pipes, 0% over 8" stone, 20% max 1/2" stone, no topsoil, organic matter, construction debris, cinders or frozen material. The ability to meet a compaction spec is sometimes required, which pretty much leaves out all the above anyway.

Unsuitable fill is purposely not defined. It simply allows for the A/E inspector to reject fill; presumably for not meeting Suitable Fill criteria, but the reason is not specified or limited. Replacement is by Suitable Fill.

Cvg has the right idea, but (again, because of the use), I would not want to mess around with a sample, unless I had a reason to think what I would get is Unsuitable. And I doubt the quarry has test reports on bank run, but maybe they do. I've just never seen any.

Remember: The Chinese ideogram for “crisis” is comprised of the characters for “danger” and “opportunity.”
-Steve

 

[LCruiser]

If it's a public works project you need to detail what's required and avoid the use of the subjective term "unsuitable fill" left to the judgement of the inspector. It's a good idea anyway. That can be a source of claims, which if nothing else lead to increased contingencies on the bids from contractors wanting to build the job as opposed to those wanting to fight for extras. You are increasing the probability of the latter type getting the job.

 

[Aldin]

i am a young engineer presently responsible for a road reconstruction project and many of the old guys on the job insist that i should use six inch boulders in the subbase,however none of the spec for subbase or base in aathho of astm indicate any thing begger that two inch down
any advise would be helpful

 

[cvg]

you might allow it in the embankment fill below the subbase, but probably not within a foot or two of the subgrade elevation