Duct Bank - Min concrete thickness

[anbm]

Is there a minimum concrete thickness requirement between the conduit edge (the one stays nearest duct bank edge) to duct bank edge?
NEC has rule for 2" concrete encased of conduits, will this be the case? i.e. 2" minimum.

 

[don_resqcapt19]

In general that is a design specification and not a code rule.

 

[Julius Right]

I agree with you , don resqcapt19.
For instance, for unreinforced concrete duct bank the concrete thickness will be 11/2" but for reinforced concrete 3".