Concrete Precast Double Tees

[joshmaughan]

Does anyone know where i can find load tables for precast double tess from the late 60's ealry 70's? I'm trying to evaluate a roof and walls that used these as the structural elements.

 

[Lion06]

try contacting a local supplier.

 

[JedClampett]

There's load tables in the PCI Design Handbook, second edition, from that era. Unfortunately, for any one size of double tee, there's several capacities dependent on the amount of prestressing. I'm not even sure you can conservatively assume the lowest values, as the double tees were usually designed for specific loads given by the designer.
If you're very lucky maybe the company that produced them still has records. But that's not very likely. Do you have the design documents? They should indicate floor and roof loading.

 

[geoffdale]

I have some charts if you want to email me- I can send them to you.
geoff@redaleltd.ca

 

[joshmaughan]

Thanks for all your help everyone! I hope I can reture the favor. The roof loading is indicated, but I think they were way overdesigned. They are 8' wide (stems @ 4') at 18-1/2" deep total (16" stems + 2-1/2" slab). The span is only 19'-8". The snow load is only 37 psf, but they have added a bunch aof roof top units. i'm trying to get a sense of how much load they can handle for that span. I'm looking to be very conservative...........

 

[civilperson]

It is a function of the number, location and size of stressed strands.

 

[kslee1000]

Instead of guessing around precast/prestressed concrete structures, have you checked to see if there exist possibilities to bring the load of new roof top additions to the end bearing such as adding elevated steel framing.

 

[geoffdale]

Sounds relatively conservative, but maybe to be sure, look at some x ray testing to see the strand size and spacing?