Combined Footing - Temperature and Shrinkage Bars

[EngrJS1]

Hello,

I am using STAAD Foundation Advance to design a combined footing based on ACI 318-14. The software computed that there is zero hogging moment but I was wondering as to why it still provided top longitudinal reinforcement bars. According to another forum, these bars were provided for temperature and shrinkage reinforcement. However, can't we just consider the bottom longitudinal reinforcement as the temperature and shrinkage reinforcement? Is there really a need to provide temperature and shrinkage reinforcement both at the top and bottom longitudinal direction of the combined footing?

 

[le99]

No, in the case of a shallow foundation, I've rarely provided top reinforcement. When provided, it was strictly due to strength considerations, not T$S concerns.