Double Tee - suggestions?
Double Tee - suggestions?
(OP)
I have a wastewater treatment plant structure near Charleston, SC with basins on 2/3 of length and 2-story building on other 1/3 (common wall between the two). The blower and pump room is in the bottom level of the building. I want to use concrete for as much of the building design as possible given the corrosive environment. The building 2nd floor framing span is 34' clear and I am planning to use precast double tees in lieu of CIP beams/slab. I have not used double tees before and think it may be a good solution for this. I am looking for any guidelines, suggestions, tips on using double tees for this application. For example camber considerations, connections at the joints, topping slab (do I get the precast sections with a topping or do I specify the topping be poured), floor finish considerations for the 2nd floor, etc. The double tees will be framing into 12" thick concrete walls on the exterior of the building.
Thanks in advance for any direction you can provide.
Thanks in advance for any direction you can provide.






RE: Double Tee - suggestions?
RE: Double Tee - suggestions?
RE: Double Tee - suggestions?
-Once they're set, the contractor has a safe working surface.
-Their mass is good for resisting uplift loads.
-They're pretty cheap per square foot.
-There's a lot less inspection/observations for them, as they're factory items. No welding, high strength bolting, concrete cylinders, reinforcing submittals, etc.
Some considerations you need to worry about is use of the double tees as a shear diaphragm. The double tees need to be connected to each other and at the ends to be used as a diaphragm. Alternatively, you can pour a reinforced topping slab on them, tie that to your walls and use that for your diaphragm, but that inceases price, construction time and loading. The topping is field installed. You never get it with the double tees. My rule is if the floor is habitable, I put on a topping. If it's a roof, no topping. That's because the double tees are usually poorly finished. You'd never want to put carpeting or other flooring on them directly. Hence the topping.
As far as camber, the double tee designer usually handles that, unless you have special requirements.
For a 34 foot span, hollowcore panels are also very good. They use up a lot less headroom.
You need to get the PCI Design handbook. It's a great reference in general, and will have a lot of the details you have questions on.
RE: Double Tee - suggestions?
RE: Double Tee - suggestions?
RE: Double Tee - suggestions?
Add a concrete beam and tie the double tees to that.
RE: Double Tee - suggestions?
Dik
RE: Double Tee - suggestions?
RE: Double Tee - suggestions?
Dik
RE: Double Tee - suggestions?
http://www.dbh.govt.nz/UserFiles/File/Publications...
RE: Double Tee - suggestions?
The attached pub is a really good read, thanks,
Dik