column spirals

[ajk1]

a) Does anyone have a Table of column spirals satisfying CSA A23.3 (or presumably the equivalent clause in ACI 318), or know where there might be such a Table? The Table would account for column diameter, spiral diameter (which depends on concrete cover, which depends on fire rating as well as durability exposure classification), grade of steel, concrete strength and spiral pitch.
Or do I have to calculate such a Table myself?
Preferably the Table should be for Canadian metric bars, but even a Table satisfying American imperial bars might be helpful as a rough check on any calculation that I may have to do.

b) Are spirals that are plain bars (with no deformations) supplied in Grade 400 steel (i.e. same grade of steel as Canadian metric bars)?

 

[Agent666]

Regarding spiral vs hoops, no difference in my part of the world. Single strength reduction factor for any arrangement or type of loading. Fundamentally behaviour is similar.

Agree lapping directly is obviously preferred in practice than what you originally proposed.

 

[BridgeSmith]

In our drilled shaft/column configurations, if the column was too tall to cast the full-length column cage into the drilled shaft, we would have bars and spiral that extended a lap length into the drilled shaft and a lap length into the column, and cast them into the drilled shaft, and then lap the column bars to them after the drilled shaft is cured. Usually we just detail it assuming the whole column cage is set in position in the drilled shaft when it's poured.

 

[BridgeSmith]

Most often, the drilled shafts are sized so that we can use the same size cage in the drilled shafts and column, either the same diameter (3" cover) or with the drilled shaft 6" larger diameter (4.5" cover in DS and 1.5" in column).

 

[ajk1]

I see.

 

[elreedyman]

In general spiral stirrups Vs normal circular stirrus. The column with spiral carry more load depends on the spiral pitch. I can give you in EcP which is similar in BS but away from CSA.

http://www.elreedyman.com