Existing Pre-cast tees

[ronstruc]

I have a project where the owner wants to add some load to an existing roof that has Pre-cast Single Tees constructed in the 1960's. I am looking to determine if the existing tees have the capacity to support the additional load. I have the original plans and the only designation in reference to the tees are 8 ft. wide single tees specified as IR30"-4d. I have not been able to find anything on what that designation means. The drawings have a section through the roof that show a tapered flange but no dimensions are given as to the thickness of the flange. The project is located in the intermountain region of the west. Does anyone have any insight on how to determine the capacity of these tees without destructive testing?

 

[JAE]

30" sounds like the depth.
the "d" sometimes was used to designate a depressed tendon profile...usually 1D or 2D for 1 or 2 depression points.
Not sure about "IR".

 

[ronstruc]

The 30" is the depth. I am aware that "D" can mean depressed. This is a lowercase "d", not sure if that means something different it also has the number 4 before it - 4d. Not sure if the 4 is a size in 16th's which seems to small at 1/4" strand or if its 4 strands.