precast double tee capacity
precast double tee capacity
(OP)
Greetings,
I have been asked to evaluate an existing building that has 4' wide (stems @ 24" o.c.) double tees that span 27 feet and some span 36.5'. The short ones have 12" deep stems and the longer span tees have 15" stems. They are mid to late 1960's and in Southern NC, near Charlotte. Metromont made them but has no record of them or any load tables for the same. Any ideas or information would be greatly appreciated.
Thank you.
I have been asked to evaluate an existing building that has 4' wide (stems @ 24" o.c.) double tees that span 27 feet and some span 36.5'. The short ones have 12" deep stems and the longer span tees have 15" stems. They are mid to late 1960's and in Southern NC, near Charlotte. Metromont made them but has no record of them or any load tables for the same. Any ideas or information would be greatly appreciated.
Thank you.






RE: precast double tee capacity
RE: precast double tee capacity
RE: precast double tee capacity
RE: precast double tee capacity
If the project is in NC, a long time friend and one of the top 5 architects (world class) I've met in 30 years works with LSV Architects, there...
Dik
RE: precast double tee capacity
Dik
RE: precast double tee capacity
RE: precast double tee capacity
RE: precast double tee capacity
RE: precast double tee capacity
Dik
RE: precast double tee capacity
Are you sure you need to know the pre-stress in the strands to determine the flexural capacity? My understanding is that the prestress is only relevant for camber and deflection purposes and not strength at failure. The tendon stress at failure is not affected by the amount of pre-stress in the tendon. The Ultimate capacity of the TT is fps*Aps*(d-a/2).
Please let me know if I am missing something.
RE: precast double tee capacity
Dik
RE: precast double tee capacity
Can over-reinforcing can be checked for without considering elastic properties? Why are we concerned with elastic properties to determine the ULTIMATE capacity?
RE: precast double tee capacity
Dik
RE: precast double tee capacity
Yes, you need to know the # of strands and the prestress force on the strands to determine its ultimate capacity. You can use ACI equations instead to get an approximation, but it will not be exact. I do not recommend the load test to determine E. The deflection during a load test is equal to the deflection due to external loads (including own weight) minus the camber. Since you don't know the # of strandd and PS, you will not be able to calculate the deflection due to external loads only. Recommend you keep looking for documentation, use non-destructive methods, and destructive if necessarry to determine the strenght of the concrete.
RE: precast double tee capacity
RE: precast double tee capacity
RE: precast double tee capacity