Urgent - Prestressed Tendon Curvature Minimum Radius
Urgent - Prestressed Tendon Curvature Minimum Radius
(OP)
Please help me,
Is there anybody who knows which code explains about minimum Radius on a curvature tendon? Is there any formula/calculation method for this minimum radius? And if the Prestressed Tendon Curvature follows the minimum radius, does that mean Hairpin Reinforcements become unnecessary? Thank you.
Is there anybody who knows which code explains about minimum Radius on a curvature tendon? Is there any formula/calculation method for this minimum radius? And if the Prestressed Tendon Curvature follows the minimum radius, does that mean Hairpin Reinforcements become unnecessary? Thank you.






RE: Urgent - Prestressed Tendon Curvature Minimum Radius
RE: Urgent - Prestressed Tendon Curvature Minimum Radius
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Urgent - Prestressed Tendon Curvature Minimum Radius
A basic rule for multi-strand tendons is 70 * duct diameter. This obviously assumes a logical duct diameter for the number of strands as the bearing stresses are related to the number of strands and the bearing area! It is not a good idea to use less than this.
Your question about hairpins is far too general to answer. I would not think that hairpins would overcome the concrete crushing and bursting problems that you get from too tight curvature. Or the duct wear or higher friction. So I would assume that they are there for another reason.
RE: Urgent - Prestressed Tendon Curvature Minimum Radius
@rapt: What do you mean? Isn't the hairpin used to bear the lateral force due to the curvature? For bursting, I think we use Bursting Reinforcement.
RE: Urgent - Prestressed Tendon Curvature Minimum Radius
Hairpins might work to stop breakout/spalling where an angle change is near a surface and towards the surface as happens at kinks in tendons near anchorages in large bridges etc. In a general area where it is concrete crushing that is the problem, I doubt that they would alleviate the problem as the concrete would have to crush before they were fully activated.