huangyhg

is there a standard for "no. 2 crusher run"
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
check out our whitepaper library.
your state dot might have a spec that you can refer to. try asking this question in one of the geotechnical engineering forums, they can probably have a reference.
regarding your compaction, do you define what you mean when you say 95% compacted....? you can compact according to the modified proctor test or the standard proctor test, but they are not the same thing.
it's a sad day when we don't know what our own specifications mean ... and logically, why we specify them
i have 10 years experience as a structural engineer and know several older engineers and contractors who refer to "crusher run" alot for use under slabs-on-grade. when asked what that means, they typically don't have a definitive answer as far as gradation. except to say it's 3/8" and smaller gravel with lots of fines. apparently that was a very common term decades ago that never went away. i spec "unwashed size no. 10 per astm d448", which is referenced in aci 302, section 4.1.4.
i also recommend you check your state's dot specs for subbase under roadways. here in wisconsin, dot gradation #2 is an excellent granular fill for use under slabs, footings, etc. it is similar to what archeng59 described--gravel with lots of fines. the fines help with compaction.
daveatkins
no.2 crusher run refers to #2 crushed stone with all of the stone dust froom crushing. #2 crushed stone is just the stone. in ny the state dot has a spec for it, where it is also refered to as a type 2 subbase. when we specify it we refer to the nysdot specifications.
recommending compaction effort and fill material is the specialty of geotechnical engineers, but structural engineers usually have a working knowledge of it too. is there a geotechnical engineer that is involved with your project? i didn't think that aerospace engineers normally get involved with things like crusher rune stone.
thanks guys,bjb has pretty much hit on the head what i thought. i didn't know for sure if there was anything else on this. i do have the spec. from the nysdot and what you say makes good sence. you're right i don't usually deal with this stuff lol. i'm also a mechanical engineer and this is some large scale heat transfer equipment i'm working on. the foundation design (based off my loadings) was outsourced by us to a small local structual company. i could not seem to get an answer from them ( at least a timely one) and figured it couldn't hurt to try here.
thanks again
aeroub, are you in ny, and does the ub in your name stand for university at buffalo?
yes and yes. in fact, one of my best friends is a stuctural engineer from ub (few years ago). i went for aero and mech.
small world, i went to ub too, i moved out of the buffalo area in early 2002 and now live near saratoga. imight be familiar with the consulting structural that was involved with your project, but don't name any names.

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