Post tensioned slab on grade demolition

[clark1007]

I need to trench through an existing post tensioned slab on grade here in Texas. My opiniion is to relax the tendons in the area and retension afterwards. Any helpful hints would be greatly appreciated. Thanks!!!

 

[Ingenuity]

Is the proposed trenching full depth? and over a large area?

If you destress the tendons you will have to use special stressing gear to re-stress.

I would try and do localised trenching without destressing, maybe consider staging the trenching and re-patching, if possible. Really depends on the dimensions you are proposing for the trenching.

The trenching should be at least 36" from any anchorages to avoid a potential anchorage failure etc.

HTH

 

[clark1007]

The trenches are full depth and long lengths...the need to move kitchen plumbing to different area in the building. After de-stressing and the cable are cut, can I re-anchor the cables and re-stress, or is there another method. Also, the areas that don't have post tensioning, should I heavily conventionally reinforce? This is a bit out of my experience, but a project that needs addressing, nonetheless.