Post Tensioned Foundation

[RDMESH]

I am used to designing the PT Slab on grade foundation with uniform interior and exterior beams. The design load on the foundation is from the stud wall and brick veneer around the perimeter of slab. The PTI slab I have designed is monolithic. Now , my question is Can I design the exterior foundations per ACI 318 with rebar and design the PTI slab on grade for minimum interior load and provide tendons only on the slab? Is there any design specification for hybrid type foundation? Please comment!!!!!!

 

[dcarr82775]

So long as you conform to the letter of the PTI method, I see no reason why you can't also apply ACI318. If you want to start mixing and matching, you need to put on your engineering judgement hat and decide if you think your methods are rationale and defensible.

I will often design to the PTI method, but then run some checks of my own, particularly when I have large concentrated edge loads. I often end up adding steel and depth beyond PTI requirements (per ACI 318) to satisfy myself things work.