Lap Splices

[steve1]

ACI 318 section 12.15.4.1 requires that welded or mechanical splices be staggered 24 inches. Two questions:

1. Is the 24 inches measured center to center or end to end?

2. Is there a similiar, or any, requirement to stagger lap splices?

We've got a debate between contactor, construction manager, and structural engineer over this issue. Basically we have a 24 inch wide beam reinforced with 8 #8's. If lap splices are used, all in the same location, then we have 16 inches of steel within the 24 (minus an inch and a half of cover)inch space. The concern is that the concrete will segregate if we attempt to place it between the steel.

 

[prsconsultant]

1.`We typically set 24" from c/c of couplers.
2. It is not required to stagger the lap splices. The lap length varies depending on if it is a class A or class B splice.

 

[civilperson]

This rule applies only to mechanical splices that do NOT meet the requirements of 1.25 fy of the bar. The detailing of location of lap splices should comply with minimum clear spacing between bars,(ACI 318-05, 7.6), 1" in your case. Thus the splices should probably be at different locations.