Helical ties
Helical ties
(OP)
I am working on a project on the construction side of things. And have a question about helical ties. The concrete colummn is 12" in diameter and the engineer has specified No. 10 (Canada) helical ties. I have never used them and am unfamiliar with them. I would like to use No. 10 circular ties. Before I go back to the design engineer is this a legitimate question? What would we expect for a result?
Thanks for all your help
Thanks for all your help






RE: Helical ties
I think you have a legitimate question, however the engineer may have good reason for the specification of helical ties. I'm not entirely certain I understand correctly, however, as I always think of helical ties as a wall remediation tool, where the continuous ties in a column would be called "spiral", with the single loops called "hoops".
Please correct me if I've got the wrong end of the stick, but in the mean time I'd pick up the phone if I were you.
Good luck with it,
Cheers,
YS
B.Eng (Carleton)
Working in New Zealand, thinking of my snow covered home...
RE: Helical ties
BA
RE: Helical ties
RE: Helical ties
There was an article on this in the istructe magazine a few years ago, I will see if I can locate it.
RE: Helical ties
hokie,
The Canadian code permits about 6% more axial load resistance for a spirally reinforced column than for a tied column.
BA
RE: Helical ties
That being said, it can't hurt to ask the question. Spirals typically have a VERY close spacing.
RE: Helical ties
I have had the oposite issue. Designer specifying circular ties and the rebar suplier wanting to change them to
helical ties. It was cheaper and faster to produce, although he probably had the equipment to do so.
As already said, it is a pertinent question and there are design implications.
RE: Helical ties
In your case, there is no reason not to accept the helical ties. As long as the spacing and size are the same, and there are 1 1/2 extra turns at the end, the helical ties are equal or better than the individual ties.
RE: Helical ties