Steel column to concrete foundation connection
Steel column to concrete foundation connection
(OP)
Where can I find information on using a nut/washer as opposed to a hooked anchor when embedding in concrete? Can I use the basic development length and the reduction factors as though my anchor rod with nut & washer was a standard hooked bar? Is there any specific criteria that I need to use when specifying size of washer? I'd appreciate any thoughts.
Thanks.
Thanks.






RE: Steel column to concrete foundation connection
RE: Steel column to concrete foundation connection
RE: Steel column to concrete foundation connection
If you have any tension on these anchor bolts, do not use hooked bars. They have a tendency to straighten and pull out. AISC recommends against them for anything other than gravity only columns.
RE: Steel column to concrete foundation connection
1. I'm assuming that anchorage to grout-filled CMU walls is applicable here. Is that correct?
2. Using equation D-4, I come up with a concrete break-out strength of 7,642lbs with my effective "h" = 5" and using 2,500psi grout. Does this seem realistic?
3. It appears that I also need to make a check of Np, which is basically a crushing failure. Does A(brg) refer to the area of the washer or head LESS the area of the bolt? I couldn't find a definition of that, but it only makes sense that that would be the case.
If I could be assured that I'm looking at this correctly, I'd appreciate it.
Thanks you.
RE: Steel column to concrete foundation connection
2.) If the answer to 1.) is that you are correct, then it doesn't seem unreasonable (without knowing your edge distance constraints).
3.) You are correct.
RE: Steel column to concrete foundation connection
ACI 318 Appendix D is for concrete and really for concrete with edges far away from the bolt locations. Once you have close edge distances, they sort of leave you hanging.
RE: Steel column to concrete foundation connection
2. Not unreasonable for breakout only necessarily, but sounds high by the time you account for the lost area and edge distance in a masonry wall (mathematically only, see 1).
3. Yup. This seldom controls in my experience.