Unreinforced concrete design allowed in ACI 350? 1

[SteveRivard]

Hello all!

I have a question that has been posed to me by a septic tank precaster: Is it permissible to design a septic tank as unreinforced concrete? I don't have a copy of ACI 350 on hand, so I couldn't answer his question as to whether unreinforced design is allowed or not.

Does anybody have an answer to this?

Regards,
Steve Rivard

 

[JedClampett]

That section (on plain concrete) has been deleted from ACI 350. I'm thinking it's not a good idea to use unreinforced concrete in liquid containing structures.

 

[SteveRivard]

Jed,
I couldn't agree more with you. The only liquid tanks that I ever designed were always reinforced to preclude tank cracking and leaking. So, while I personally didn't think it was a good plan, if the code were to allow it, it becomes an entirely different answer to the precaster.

In any event, thanks for the information!

Regards,
Steve Rivard

 

[WWTEng]

I have a copy of ACI-350 and it doesn't address plain concrete. Chapter 22 is just one paragraph clearly saying that "structural plain conc is not permitted in environmental engineering conc structures"