Existing 30" Precast Concrete Tees
Existing 30" Precast Concrete Tees
(OP)
I am working on a building from 1966 that has roof framing that consists of 30" Precast Concrete Tees @ 8'-0" o.c. that is spanning approximately 68 feet. Does anyone know where I can get some information on the capacity of these tees? Any rules of thumb for being able to make cuts in existing framing and not jeopardizing the tees?






RE: Existing 30" Precast Concrete Tees
I don't think there's much you can do as the number, diameter, material grade (probably 270 ksi) and location of tendons would be unknown.
Best thing for cuts in the floor is through flanges near the ends where flexure is minimum.
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RE: Existing 30" Precast Concrete Tees
RE: Existing 30" Precast Concrete Tees
As JAE said, it will be difficult proving that it will work without knowing the what the tendons are.
Professional and Structural Engineer (ME, NH)
American Concrete Industries
www.americanconcrete.com
RE: Existing 30" Precast Concrete Tees
I've got the 2nd Edition PCI Design Hnadbook (circa 1975) and while they don't have 30 inch tees or double tees, the ones on either side of that (32" and 24") seem to easily span 68 feet, depending on the tendon pattern and topping.
RE: Existing 30" Precast Concrete Tees
RE: Existing 30" Precast Concrete Tees
Professional and Structural Engineer (ME, NH)
American Concrete Industries
www.americanconcrete.com
RE: Existing 30" Precast Concrete Tees
Maybe the local manufacturer has an engineer who seals his drawings who might give you some information. Even if the architect has to pay for it, it's cheaper than spinning your wheels.
RE: Existing 30" Precast Concrete Tees