Rebar Lap Question

[Lion06]

So, I was visiting a job today to take a look at rebar for a very large concrete beam carrying significant load (vertical, horizontal, and torsional). This is for an existing building, and the working space is minimal. The horizontal reinforcement is spliced at roughly the third points - there are hooked horizontal bars at the ends extending roughly 40% of the span at each end and then a straight bar in the middle lapped with each of the end bars.

The problem I noticed is that one of the corner longitudinal bars is not within the stirrups (only the straight bar over the middle 30% or so of the span). The two hooked end bars that are lapped with this particular straight bar are inside the cage, but the straight bar is outside the cage.

I raised this as a concern for a couple of reasons.

1) The bar has no confinement and is held in place only by ties to the stirrups (and bars that it's lapped with over the lap length.

2) Part of the reason that stirrups can develop Fy in such a short distance is because it's hooked over the top bar. If that isn't the case then that could have an impace on the effectiveness of the stirrups at this location.

The more senior engineer I was with didn't think it was a big deal because 1. the lap length was larger than it needed to be, and 2. There's a large amount of cover at this location > 6" so that the confinement issue really isn't a problem since that much concrete is not likely to spall off.

I'm still not convinced. Can I get some second opinions?

I see the point about so much cover being unlikely to spall off, but it still doesn't "feel" right when I look at it.

 

[cntw1953]

Agree.

 

[boffintech]

Am surprised no one suggested petrographic analysis of the cores to determine the concrete's general quality and condition, and to estimate the entrapped and entrained air contents.