NDT of existing concrete and wooden facilities 1

[Mike62]

I am a DOD facilities engineer and have an assignment to determine residual life of numerous WW2 vintage hangars per ASCE 11 and other standards. I will contract out the work to an AE firm but I am lost as to how to prepare an estimate for the NDT engineering services. Does anyone out there know of a database of NDT testing and analysis costs that I can access?

 

[Archie264]

NDT = Non-Destructive Testing?

 

[Mike62]

Yes. Such as sonic/ultrasonic, electromagnetic, infra-red, etc

 

[Ron]

Mike62...don't know of a database for such. Each of the tests you mention has significantly different cost parameters. I would suggest you contact a local consultant or consultants who will have the capability of each of the NDT methods you need and ask them you offer unit price or ballpark estimates of same.

 

[msquared48]

I am surprised that the DOD does not have a database of that based on prior contracts.

Mike McCann, PE, SE (WA)

 

[racookpe1978]

Hmmmn.

For power plant work requiring many different individual NDE exams on many different systems and points (a weld here, a dye-pen check over there, another weld over there, a UT check over on that scaffold, a visual inspection over there, etc, etc, etc, we assign one (or two) certified NDE tech's to cover either one shift (or two shifts) for the entire outage. Thus: cost = nbr of techs x dollars per shift x nbr of shifts.

Then, whatever comes up gets inspected. If there are no welds to check that shift, you lose money, and they have just been "waiting". If there are 12 or 15 or joints or inspections or whatever, then they have been busy.

The ONLY other way to cost the job is to know exactly how many joints or bolts or plates have to be inspected, and exactly how much each inspection will take. (Yeah, right.) And have everything exactly ready (scaffolding, paint removal, asbestos removal, cranes, grinding, etc.) all perfectly ready at the start of each inspection. (Yeah, right.)

Then it is = cost per inspection x nbr of inspections.

 

[dhengr]

Mike62:
It seems to me that you might be putting the cart before the horse here. How would anyone know what testing was required before they made an initial inspected of the bldgs. or facilities in question? I don’t know of any listing which says if it’s a wood bldg., x,y,z tests must be req’rd. But, I do know of dozens of things I would want to look at when I walked into that bldg. to start to assess its condition and needs for a particular use. And, that’s an ongoing process; when you see one thing, that causes you to look at three others. In some cases the answer might be bulldoze it. Maybe you should hire a consultant to help you put this program or request for proposals together, since you seem at loose ends as to where to start. You and your bosses need to make some initial determinations too, and ‘residual life’ may not be the best or first question to ask. And, this first consultant might help you at that level too. What do you expect to use each facility for, does it just have to be made reasonably safe and functional for that use, or does it have to be brought up to current code? I suspect, in some cases, you can pull some strings and don’t have to meet the current bldg. code or deal with the local AHJ.

 

[glass99]

My experience of existing structure evaluation is that it is primarily visual. For metals there is plenty of NDT, but timber and concrete are less obvious how to test. Ok you can take core samples or do a Schmidt hammer, but its a bit pointless. When concrete deteriorates its usually the rebar rusting, so you will see spalling. When timber degrades its usually rot or termite damage. Even steel you would primarily assess visually. I would only do an X-Ray on a weld if i really thought there was some reason to do so. I guess you could x-ray some percentage of the welds.

 

[Brad805]

I think step #1 is a condition survey of each facility. Part of that teams scope should be to outline the future NDT testing. I am sure you could come up with a generic NDT testing program, but you can expect your costs may be significantly greater as you will end up testing far more than if you have an experienced professional define the basic parameters to investigate.