Non-Contact Lap Splice

[cancmm]

I need to detail a non-contact lap splice that exceeds the allowable ACI spacing of 6" (roughly 8-9"). Has anybody come across design guidance for such an issue?

Thanks in advance!

 

[KootK]

Yeah, this comes up from time to time around here. The starter advice to get you up to speed:

1) The issue is containing the strut that forms between bars.

2) You should be familiar with this: Link

3) In a pinch, you can always design the lap using a strut and tie model.

4) In either the NZ or AU code, I think that you can do an extended non-contact lap splice so long as you add [1.5 x bar spacing] to the length of your lap.

I use #4 most often.

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.

 

[cancmm]

Very helpful. Thanks!

For future reference, the WSDOT paper referenced has been incorporated into AASHTO LRFD as well. However, it applies specifically to columns with longitudinal reinforcing that anchor into oversized shafts.