Cool...using expanding foam to level concrete

http://izismile.com/2015/01/22/how_to_lift_crackeduneven_concrete_driveways_with_foam.html

Not sure how it generates enough pressure to lift a slab without spurting out a dozen ways first, but it's cool to watch.

 

I imagine the containment of the foam is the first consideration before applying, otherwise the combined weight of the slab and the pressurized injections could lead to some unforeseen blowouts.
Note: per the vid, it appears to be a very slow process (hence the time-lapse & expedited vid sequences).

 

Thanks for the vid. I need to do that to my driveway someday.

 

Very interesting!