Thanks. Imminent - those are through bolts with plate washers. No spalling on the stems. This is the ceiling above a pump/motor room. The are ammonia refridgeration lines in the area, but no reported leaks. I'm going to attempt to make a determination on the fasteners.
Thanks again guys. No recent new roofing. It's been several years. Still, could be from old fasteners. Also, it has not been a particularly cold winter here. Past years have been much worse. I'm having a hard time finding anything that has "changed" this year. That's why it's so strange.
Thanks guys! Any thoughts on why there would be no spalling on the stems, only the bottom of the slab portion? Thinner concrete (2-1/2" slab) maybe? Stems are about 6" thick. Maybe the steel mesh in the thinner slab portion is adding to the stresses, or helping provide failure planes.
Thanks Ron. I will look for that. FYI, the spalls have cracked "through" the aggregate, and not around it if that means anything. So the aggregate is fractured along the spalling.
I have been asked to look at some spalling that is occuring along the bottoms of some precast/prestressed concrete roof double tees in an industrail building. T
he span is very short (22') and the tees are 18" deep. The only load is dead load (self wt.) and a 40 psf snow load, so the loading...
ATSE:
Thanks. Yes I did use ACI 350 in the design, so I do have at least .oo5% horiz. steel. I'm actually about .007% at my worst case (top of the wall). Sounds like I could stretch the 60' a little bit, but not too much. The XYPEX should help in the joints, along with the PVC water stops...
You need to x-ray the wall and determine how it is reinforced. If it is not reinforced................game over........walk away. There will be problems down the road. If is is reinforced, and analysis determines the secton has capacity to resist the loads and added 1" eccentricy, you should...
I have designed a circular water tank that is appoximately 150 feet in diameter and 16' tall. It has a concrete lid with interior columns. I have specified construction/control joints, with water stops at approximately 60 feet on center in the floor and lid. And vertical construction/control...
I know about the bracing lengths in RISA. But if you read about the code checks in RISA, it does not consider certain parts of the AISI code. I just find it very difficult to believe a 10' long 3.5x1.625x43 mil stud can take 1000# in compression, with no lateral bracing, but that is what RISA...
Thanks for your help all. I am quite sure RISA does not analyze this correctly. It ignores parts of the code in certain conditions. I think this is one of those conditions......
I need to determine the axial compression capacity of a metal stud section that is not braced laterally at all. The hieght is 6.1 feet. The axial load is 400#. I believe all of my software assumes lateral bracing, and I do not have a copy of the AISI Code. I was thinkig of an 350S162-43 or...
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...
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.
