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RE: LRFD 3rd edition has arrived - VT weld testing

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This is not so unfair as it may seem.

If you tell the contractor that the rejection criteria is "x" but then
implement an inspection protocol capable of       finding smaller defects
and then reject those smaller defects you have in effect changed the
rejection criteria.  In such an instance the contractor should both moraly
and legaly be paid for the change is scope.

Remember there are honest differences in opinion as to what size of defects
are acceptable.

One technique that you can utilize to deal with this is to state in the
peoject  specifications that you reserve the right to reject welds using
ultrasonic, magnetic partical, and dye penetrant inspection criteria in
addition to visual testing criteria.  Then you specify some random
utrasonic and magnetic particle testing be done.  Finally you state in the
specifications that the testing specified is the minimum amount of testing
and that additional testing may be required.

The approach listed above would allow you  to reject welds based on the
more restrictive ultrasonic, or magnetic particle acceptance criteria.  The
one consequence is that the contractor will likely increase his bid to
cover the cost of repairing the additional defects found.


Mark Gilligan

---------------------------------------------------------------------------
-----
Ken,
 
This really is not new.  The AWS D1.1 is referenced by engineers all the
time as a basic spec, "All welding will conform to the requirements of AWS
D1.1", but I question how many engineers have really taken the time to read
and understand the AWS.  The AWS provides that visual testing will be
performed, and though the procedures and requirements for NDT are
described, the requirement as to whether or not NDT shall be performed is
consistently referred back to the engineer (i.e. the Construction
Drawings).  
 
If testing other than visual is to be required on a project, the project
plans and specifications must outline what is required and when.  There was
an article series in Modern Steel a few months back that dealt specifically
with these issues.
 
Paul Feather
 
 
 
 
----- Original Message ----- 
From: Ken Peoples 
To: Seaint 
Sent: Tuesday, November 27, 2001 7:30 AM
Subject: LRFD 3rd edition has arrived - VT weld testing


I just received my LRFD  Manual - Third Edition.  It looks like quite a
manual!  I can't wait for the "unified" manual, it may need its own
bookshelf!
 
Anyway, I was surprised to find the following paragraph regarding weld
testing on page 8-4:
 
"In the absence of instruction, AWS D1.1 Section 6.6.5 states that the
fabricator or erector is responsible only for those weld discontinuities
found with VT.  If additional inspection more stringent than VT is later
required, the owner is normally responsible for the cost of weld repairs
other than those identified by VT"
 
I am not a weld inspection expert, but that to me sounds a lot like this: 
"If I didn't tell you that I was going to check the compressive strength of
the concrete, then if I do check it later and it is not OK then it is the
owner's problem"  I'm sure I must be missing some basic fundamental
difference because of my ignorance, but what is it?
 
As always, thanks in advance for your insights.
 
Ken
 
 
Kenneth S. Peoples, P. E.
Lehigh Valley Technical Associates
-------------------------------------------------

References: 

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