Slabjacking is a minimally-invasive concrete lifting process. Small holes are drilled through the concrete, and lifting material is injected under the slab.
The filler material used in slabjacking is a polyurethane foam. As it is injected under the slab, it foams up, lifting the slab back into position. This foam product is environmentally safe, sets up almost immediately, and in most cases is a permanent solution.