Mudjacking: Is a process used for raising concrete slabs, foundations and steps by which a crushed limestone and cement grout material is hydraulically pumped through 1 1/2 inch diameter holes drilled into the concrete. The grout material spreads out filling the cavities and voids, gradually raising the concrete back to its original position. Any holes that were drilled are then patched with cement. Many times the procedure can be done avoiding the drilled holes on the surface of the slab by injecting the grout from the side (slightly additional cost).
What is COMPACTION GROUTING ?
Compaction Grouting: It is the process where a cement grout mix is pumped at a determined depth to achieve compaction and/or a somewhat rigid column. (Used where compaction has been lost or a void has developed and increased support is needed. Usually under a footing and at depths of more then 5 feet.) Footings and structures can also be stabilized by this method.