Reinforcing Steel Laps

[asdf]

Looking for a few opinions. I am building a pylon, with reinforcing steel, predominantly bundled bars, ranging from No. 9 to No. 14. With the exception of the No. 14 bars, I would like to lap, instead of mechanically coupling, the reinforcing steel. Some have advised me that the laps must be staggered at least 24 inches, other have told me the laps must be staggered the length of the lap. Is there an industry standard? Code stipulation?

 

[wiktor]

Yes, it's a code stipulation. Check AASHTO "Splices of Reinforcement"

 

[yakpol]

Park and Paulay in their classic "Reinforced Concrete Structures" textbook recommend to stagger lap splices 0.5 or 2.0 of splice length to reduce cracking. 1.0 splice length stagger is specifically criticised and not recommended. It makes sense since transverse crack through beginning of splice in one bar and end of splice in adjacent bar is crossing stiffer region reinforced with the same steel area. If you want I can fax this page to you.

yakov@yakpol.net

 

[Dinosaur]

The AASHTO requires bars spliced in a bundle to be spliced one at a time. Don't forget to check your clear distance between bars also when your done. After you get past two bar bundles, it gets harder to add more steel in a column unless you start a new layer (ring of steel).

Regards