I'm not sure there is one... I usually use the prescript 'B' to denote a beam and then the first digit signifies the floor or area, for example Beam B211 would be on the second floor (BR211 would be a roof beam). I also use the format Bfnn for all beams unless I anticipate more than 99 beams on a floor, in which case, I would use Bfnnn as the format. I also try not to locate B211 at some isolated location that is outside the sequence of beams in the area. If beams are similar, then I use the same mark number. The reference to the size (and or reinforcing) is either on the plan as:
12X24 BM
2-15M T
2-20M B
1-20M6.6 TX AT SUP (top extra at support)
6-10M@10, REM 10M@24
TYP ALL BM MK B211
or in a tabulated schedule beams noted on the plan as B211. For something with that many different beams I'd likely use a schedule.
Good man, dik! I really wish everyone approached structural detailing as such and fought to maintain the logic as long as possible, especially on very large complex projects.
I think it is also very important to avoid naming Post tensioned beams and conventionally reinforced beams (in concrete) with similar names. Before I graduated from GA Tech, I spent most of my time detailing formwork shop drawings. I recall one job where the beams designations were PBXXX and PBBXXX, one PT the other conventional. If it confuses those in the office, the field will feel a greater hurt.
