Corbel detailing
Corbel detailing
(OP)
This detailing practice may be perfect OK. But I am suspicious since ACI doesn't have this. I am not sure what is wrong and therefore putting it out here for people to comment. Thanks!
Basically, the corbel has a continuous primary and framing bar. Both ends of the bar extend well into the supporting wall. There is an anchor bar at the outer end, but not welded to anything. My concern is anchorage of the primary bar. ACI states:
At the front face of a bracket or corbel, primary
tension reinforcement shall be anchored by (a), (b), or (c):
(a) A weld to a transverse bar of at least equal size that is
designed to develop fy of primary tension reinforcement
(b) Bending the primary tension reinforcement back to
form a horizontal loop
(c) Other means of anchorage that develops fy
Is there any reason why ACI doesn't have "integral" primary bar as a suggestion?
Thanks!
Basically, the corbel has a continuous primary and framing bar. Both ends of the bar extend well into the supporting wall. There is an anchor bar at the outer end, but not welded to anything. My concern is anchorage of the primary bar. ACI states:
At the front face of a bracket or corbel, primary
tension reinforcement shall be anchored by (a), (b), or (c):
(a) A weld to a transverse bar of at least equal size that is
designed to develop fy of primary tension reinforcement
(b) Bending the primary tension reinforcement back to
form a horizontal loop
(c) Other means of anchorage that develops fy
Is there any reason why ACI doesn't have "integral" primary bar as a suggestion?
Thanks!






RE: Corbel detailing
RE: Corbel detailing
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Corbel detailing
RE: Corbel detailing
RE: Corbel detailing
RE: Corbel detailing
RE: Corbel detailing
RE: Corbel detailing
RE: Corbel detailing
RE: Corbel detailing
I would expect the arrangement shown below to perform better than a welded anchor bar. I'll take conventional development/anchorage over localized mechanical anchorage any day. It's just not a popular configuration because it requires a long corbel and/or rather small primary bars.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Corbel detailing
RE: Corbel detailing
No, they're not the same thing. But they are definitely related. Development alone does not guarantee anchorage. Hence the development of ACI Appendix D for post-installed rebar etc. However, development across a competent, restraining compression strut does guarantee anchorage and is, in fact, the most common form of rebar anchorage. That's how the bottom bars of simple span beams are anchored at the supports.
No inverted tee beams for you? Or cantilevered bridge bents, which are really just corbels in macro? In my experience, both of these forms utilize a version of the PCA method rather than mechanical anchorage.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Corbel detailing
RE: Corbel detailing
Excellent. Never, then, shall I accuse you of hypocrisy.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.