post-tensioned strand layout : anchorage end @ skewed slab edge

[hippo11]

I am laying out some PT strands in a two-way slab that has non-parallel slab edges with and irregular column layout...in other words it's sort of a big parallelogram slab shape.

I am trying to figure out the best way to lay out the strands in plan.

My main question is, is it unreasonable to expect the PT contractor to have the anchored ends at an angle not flush with the edge of slab? He'd have to make little anchor pockets I guess to provide a flush perpendicular surface.

Basically it's a choice I have to make: straight (in plan) tendons but funny angles at the stressing points, or funny strand layouts to create flush angles at the stressing points.

Anyone have any suggestions/references? I just don't know if I want to show the anchor at 13.72 degrees relative to the edge-of-slab.

Thanks.

 

[graybeach]

I do not think it is unreasonable to expect a PT contractor to make oblique pockets. It is done all the time in beams when the tendons are not straight.

 

[csd72]

13.72 degrees is a big large to put in the tendons as a horizontal kink (particularly if it is to all of them).

Put it in pockets and show a detail giving the dimensions of the triangular pocket and distances along the skewed edge to all tendons. There is no reason this could not be built.

csd

 

[AUCE98]

PT Suppliers can supply 30 and 45 degree angled pocket formers for this type of condition. From those, along with the standard type, the contractor can cut the pocket formers to fit to the slab edge if it is an odd angle.

AUCE98

 

[hippo11]

AUCE98, can you tell me where I can read more about the angled pocket formers? A catalog or something?

Is it a big deal to cut, say, a standard non-angled pocket former to 1.26 degrees? How bout cutting a 30 degree standard pocket former to 31.26 degrees?

I'm just trying to gage the difficulty of skewed anchorages.

Thanks everyone for the help.

 

[AUCE98]

hippo11,

I would look up Hayes Industries,

http://www.hayesindustries.com

or General Technologies, Inc,

http://www.gti-usa.net.

Those are the two main suppliers of PT accesories. You could also call a local PT supplier such as DSI, Suncoast or VSL.