ACI 21.6.1 Requirements being applied to Gravity Columns?

Question

I have some interior gravity-only concrete columns that keep getting the error that they don't meet the dimension requirements of ACI 21.6.1. But why would gravity columns need to meet those seismic requirements in the first place? How can i fix this? 
 
 Thank You

Seth Guthrie · Answer

I assume we are talking about ACI 318-08 (or 11) here. The governing section of the code is 21.13, 'Members not designed as part of the seismic-force resisting system'. This section is applied to gravity columns when the SDC is D, E or F (note this is set in Criteria - Frame Type). 
 
 This section essentially forces the gravity columns to be designed with more reinforcement and references other sections such as 21.6. For a complete list of the code sections that 21.13 cross references, see the Ram Concrete Column Manual, section 4.8.4.

Seth Guthrie · Answer

I did some further review and here's what I observed. The gravity columns are getting checked for Section 21.6.1.1 only when Pu > Ag*f'c / 10. We get here via 21.13 -> 21.13.4.3. 21.13.4.3 references section 21.6.3, 21.6.4, 21.6.5 and 21.7.3.1 but NOT 21.6.1. I will file a defect to have 21.6.1 and 21.6.2 exempted for gravity columns. In the meantime, if this is the only failure or warning on your small columns it should be fine to use them.

Defect 569895: ACI 318-08 (ACI 318-11) section 21.13 when Pu / Ag*f'c/10 incorrectly checks 21.6.1.1 and 21.6.1.2 for gravity columns