Using Hollow core precast slab in stead of structural slab on grade

[Robbiee]

Hi all,
Thinning of using a Hollow core precast slab in stead of structural slab on grade. The structural slab on grade is needed because grade can not support the slab and it needs to be desiged as elevated slab.
Being too close to grade, I am thinking the precast slab might have some installation and other issues. Any one used it and if have any comments to share including cost comparison?
Thanks

 

[jayrod12]

We have done this. Not a big deal at all, except they can't easily install plumbing after the fact. That tends to go for a cast-in-place slab on void, but it's easier to rough mechanical into a cast-in-place slab.

If you're going the precast route, have a semi accessible crawlspace. That way if repairs are necessary to underslab services, you can get to them. Even if it means a true crawling only space.

 

[JLNJ]

How are you going to handle negative moment regions?

 

[Robbiee]

Jayrod12: thanks for your comments.
JLNJ: if the option precast is used, the panels will be simply spanning between lines of walls/grade beams.