Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

Re: Radiographic inspection

[Subject Prev][Subject Next][Thread Prev][Thread Next]
In a message dated 98-03-28 17:37:40 EST, you write:

<< 1.  Occasionally it is necessary to drill holes through post-tensioned
slabs
 for anchor bolts and sometimes 6" diameter holes.  Can holes be drilled
 safely without  breaking a cable?  What happens if a cable is broken?  Are
 there other methods of detecting cables besides radiographic inspection?
 
 Sam Love >>
     I regularly work on remodel projects with 5" post tension slab on grade
and it is easy to locate cables with pachometer and cut concrete between them.
If a cable is broken it can be repaired . A contractor called on a remodel
where he had not known it was P.T. and he had cut through several cables ( it
is not possible to tell when they are cutting since it makes no sound louder
than a saw ). They can break out concrete to expose more cable, add couplers
and retension. It cost $3000. for the approx. 6 in that case. Of course this
is not desireable or as good as original.  This would be significantly more
difficult  ( $$ ) when the slab is not on grade.
      When walls or slabs above grade are too thick to use pachometer, i have
used x-ray successfully. This was about $650.00 for about 4 shots. more shots
would be less per shot as there was significant set up/ travel cost. Make sure
they also bring a pachometer so you can find the right place to x-ray. Hope
that helps even though its not exactly your condition.
     Tom Harris, SE
     Thousand Oaks, CA