CSLB General Building (B)Site Work, Foundations and ConcreteMedium
A structural plan calls for #6 rebar (3/4-inch diameter) to be spliced with a lap length of 40 bar diameters in a footing. What is the required minimum lap splice length?
- A30 inches
- B36 inches
- C40 inches
- D24 inches
Show answer & explanationAnswer & explanation
Correct answer: A. 30 inches
A #6 bar has a nominal diameter of 0.75 inch. Multiplying 40 x 0.75 inch = 30 inches, which is the required minimum lap splice length.
Why the other options are wrong
- B. 36 inches overstates the calculation for a #6 bar at 40 bar diameters.
- C. 40 inches would apply only if the bar diameter were 1 inch.
- D. 24 inches would only be correct for a smaller diameter bar such as #4.
Rebar Lap Splice Length
The overlap distance required between two rebar sections to transfer load, typically expressed as a multiple of bar diameter.
- Common lap splice requirement is 40 x bar diameter (varies by design/code)
- Bar diameter for #6 rebar = 0.75 inch
- Lap length = bar diameter x multiplier factor
Memory trick: 40 times the bar size gives the overlap prize.