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Re: ASTM A36

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> From: "Carter, Charlie" <carter(--nospam--at)aisc.org>

> >Paul Ransom wrote:
> >Designers: At the very least, include a requirement for random mechanical
> >testing in your specs. It is not adequate to rely on the "mill certs."=20
> 
> I'm all for quality and quality assurance, but I think this is too much =
> for routine materials and mill certs can be accepted as evidence of =
> conformance (note comments on mill certs below). By routine materials, I =
> mean the standard base grades for the various structural products =
> (summarized periodically in Modern Steel Construction and listed in Part =
> 2 of the AISC Steel Construction Manual) and common alternative grades. =

I agree that mill certs are adequate as you describe. However, the steel
that arrives on site is frequently 2 levels removed from the mill,
especially on a small project. It is nearly impossible to qualify what
you have received.

> The exception I recognize for this is the case of a party to a contract =
> engaging in deceptive behavior. If that is a concern, the nature of the =
> problem is not the mill cert, but rather the deceptive behavior. =
> Otherwise, you'll only be adding cost for the owner unnecessarily if you =
> call for random testing of all structural products.

Again, it is not the mill cert with which I am concerned. However, I
have first hand knowledge of 2 occasions where the large quantity of
ASTM spec material delivered did not match the mill cert. One was
identified because welds were snapping off during fabrication. All
parties were "reputable".

On a small delivery, I found A36 material instead of A992. There were
people in the delivery stream that didn't know that steel came in
different flavours.

I am sure that there are other stories in the industry. Random testing
should be part of the fabricator's QC, even if it is only to keep their
suppliers honest, their lawyers out of court and the bldg owner's costs
low. The fabricator can do more to affect the owner's costs than my test
requirements.

Not all the steel that I see comes from the mills up the street
(Hamilton).

> specifications and acceptance criteria identified. What I mean by this =
> is, I fear the result of a project specification or drawing note that =
> attempts to do well with a general statement like "Contractor to perform =
> random material testing ..." but actually defines nothing about what is =
> required, how the testing is to be performed, or what test result is =
> acceptable.

I will balance my requirement for random testing against the tonnages
involved and consequences of getting inappropriate materials. I will
specify explicit requirements if I feel that is necessary. I want to see
some effort that the fabricator will accept responsibility for what they
are delivering, rather than saying it was their supplier's
responsibility, ad infinitum up the chain. I can waive this requirement
at my discretion. A mechanical test is inexpensive. 

> phi factors and omega factors. There are so many other places I'd be =
> looking at variations before I worried about steel strength, if I =
> thought variations were a problem. Even in concrete where we mix a batch =
> of rocks together, our past history shows us that material variations =
> are addressed properly in our design standards. Note that comment is NOT =

I spec concrete testing as well. I am a non-specific material cynic. I
am not concerned about the material variations that normally occur and
which are covered in the design standards.

Have a fun time in San Antonio. I'll have to miss it this year.

Regards
Paul

-- 
R. Paul Ransom, P. Eng.
Civil/Structural/Project/International
Burlington, Ontario, Canada
<mailto:ado26(--nospam--at)hwcn.org> <http://www.hwcn.org/~ad026/civil.html>

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