Development Length
Development Length
(OP)
CSA A23.3 only considers deformed bars when calculating development length. What factor or equation do you use if the bars are threaded? or is it normal practise to assume that threaded bar are the equivalent to deformed bars?





RE: Development Length
One option is to thread the end of a reinforcing bar and either use it directly or connect to threaded rod with a hexagonal joiner.
You will usually need to thread the bar a size smaller than the nominal bar diameter and you will need to check with the bar manufacturer what affect it will have on strength and ductility.
RE: Development Length
RE: Development Length
RE: Development Length
Use of a headed anchor or nut and washer on the rod (as suggested above) should comply with ACI 318 App D, or equivalent. Where the anchorage has significant embedment and/or confinement by reinforcement, look at ACI 318 requirements for headed bars, since App D doesn't really do justice to supplemental reinforcement and confinement.
RE: Development Length
I am having a similar situation with a threaded rod in tension, 28" deep with a nut/washer. The edge distance is 14". What requirements for headed bars are you referring to?
RE: Development Length
If using a washer, it needs to be a plate washer stiff enough to transfer the anchor tension into the concrete, something like 2.5" x 2.5" x 5/16". Standard washers are too 'limp'. Now, the bottom nut will also need to be 'locked' in place. Staking HARD in 2-3 places works, and tack-welding it twice is best. Too much work/$$ for me.
Just put an "L" or "J" bend in your anchors. Done.