Compression Lap Splices in Concrete Columns

[CURVEB]

According to ACI318-11, my understanding is that column splices must conform to section 12.16.1 in that the compression lap splice length shall be 0.0005fy x db, which corresponds to roughly 30x db (for 60 ksi bars). This is, of course, assuming that there is no tension or bending in the column that would require a longer splice length.

My question is could you ever justify using less than 30db for your column splice? Can it be reduced based on the strength of concrete? My understanding is that it cannot.

 

[MrHershey]

For compression splices in general, no.

For columns in particular you may be able to go a little less. See 12.17.2.4. You may be able to qualify for a slight reduction based on tie size/spacing over the lap splice. If you've got spirals you can take a 25% decrease in splice length per 12.17.2.5.

 

[CURVEB]

Thanks.