AASHTO Type I Beam

[BridgeEI]

I have a project that we are considering using the Type I beams, but it seems like the local precasters can't find the forms anymore. It's not common to use this beam but we have a special circumstance.

Wouldn't the precasters still be able to do the beam even if it was 3-5x more expensive than a regular beam? I would think they do custom shapes on a somewhat regular basis.

 

[bridgebuster]

If you're willing to pay the price there shouldn't be a problem. Of course, the precasters might be thinking it's not worth the time and effort, even at 3 to 5 times the cost. If you're ordering 1000's of feet it could be worth it to a precaster.

As you noted, the Type I beam is going the way of the dinosaur. 3 years ago I was working on a design-build project - 1 mile of structure, all precast - precasters were promoting NEXT beams and bulb tees not AASHTO beams, even for the long spans.

 

[BridgeEI]

Are the NEXT beams double tees? There's only a couple hundred feet of beam so it may not be worth it to them.

 

[gwynn]

A google search gave me this for the NEXT beams

http://www.pcine.org/cfcs/cmsIT/bas...le&fileID=F65CAF3A-B892-A6EB-0697898CBBDF0D30

.

The type F look like they could be a disaster from the construction engineering standpoint, unless you aren't planning on having the contractor run the finisher at the edge of deck.

What forms do the precasters local to you have?

 

[TehMightyEngineer]

If we don't have the forms at our plants then the cost of fabricating one-off forms using a combination of aluminum panels, plywood forms, and secondary pours can eat up a lot of time (and space) in the shop which causes delays for other customers. Unless we can justify the time (usually through a large cost increase) I can easily see a precaster passing on the job. A large enough job can justify fabricating a steel form for those pieces but is usually only done if there's sufficient lead time to get a steel fabricator lined up and a good chance the forms can either be reused or sold.

Overall it usually boils down to how busy we are and how much shop space/time it takes to make a custom form. Your local precaster can likely work this into their schedule if you have a longer deadline; but if they're busy and you need it right away expect to pay out the nose or go to a non-local precaster.

Professional and Structural Engineer (ME, NH, MA)
American Concrete Industries

http://www.americanconcrete.com

 

[BridgeEI]

Thanks for all of the responses, it is greatly appreciated. It looks like this job has everything going against so we'll be proposing a different solution that may be more cost effective.