Definition of concrete detailing acronym

[acsmn]

I am analyzing an existing concrete floor for new floor loads. I have the drawings, but I am not famaliar with some of the acronyms used on the drawings. The drawings are from 1969. I am looking at a three-span cast-in-place concrete strucutral slab and trying to determine the frequency of slab renforcing. On the plan view of the drawing it shows that some of the reinforcing is bent between zones of negative and positive bending; below this it shows that there is bottom reinforcing in each span. This reinforcing is labeled #6 @ 5" o.c. O.A.B.U. (or Q.A.B.U or maybe B.A.B.U). In another area of the floor the reinforcing is labeled #6 @ 4" o.c. I.S.A.B.U. Does anyone know what these acronyms stand for? I think it has something to do with how many bars are bent between the top and bottom of the slab, but I don't know for sure. Thanks

 

[dcStrucEng]

Are the reinforcing bars labeled #6@5" perpendicular to the ones labeled #6@4"? Because then the "O" and the "I" could stand for "outside" and "inside." I'm not sure what the "A" stands for. Perhaps the "B.U." stands for "bent up." Hope this helps.

 

[acsmn]

The #6@5" and the #6@4" are not perpendicular to one another. There are two different conditions in the slab that they detailed a slab A and a slab B. In both cases the reinforcing is primary reinforcing. I am thinking it is suppose to read B.A.B.U. and means "bend alternating bars up" or "bend all bars up," but there is a big difference between those two.