Pressure Grouting
Is the common term used to describe the pumping of grouts and mortars as opposed to tile grouting in bathrooms etc.

Slab Jacking
Is an old term used to denote lifting of concrete slabs.  It is understood today as being the use of quite fluid cement slurries to lift slabs.  This process is based on force = pressure x area. SlabJacking is not a reliable system, because the thin fluid slurries flow readily and leak easily without effectively lifting.

Mud Jacking
Is the more current (and American) term used to denote the use of very thick mortars to lift concrete slabs and structures.  The process works on force = pressure x area and is aided by the density of the mortar. The MudJacking system offers much greater control.  Correctly formulated MudJacking grouts prefer to lift rather than spread.  Groutech have developed specific and very special formulations for this purpose.

Is the result of any structure settling to a lower level due to gravity.  The causes of subsidence are Erosion, Compaction, and or Reactive Clays.  Erosion is when fines soil / material is removed by running water.  Compaction occurs naturally when sand / soil particles take up less and less volume as they move and fit together like a jigsaw puzzle.  Poor compaction on new structures is very common.  Reactive Clays swell when their moisture content rises and shrink when their moisture content drops.  All of these processes are directly affected by and exacerbated by water in virtually every case. 

Is the installation of piles below an existing structure.  The process is exactly the same as piling. The difference being that they are installed after the structure is built and has unfortunately subsided.  Grouting below slabs in any form IS NOT underpinning.  Underpinning is primarily used to correct subsidence in footings.

Microfine Cements

Are made up of very fine particles.  There are two common types.  Slag based microfine cements and Portland based microfine cements.   Slag based are by far the best due to their lower maximum particle size and their very consistent quality.  Portland based microfine is ground Portland cement.  Portland microfine is very inconsistent in particle size and has a large maximum percentage of particles.   The terms, Ultrafine, Superfine, Megafine, etc are marketing terms to build perceptions on their fineness.  Don't be misled by clever sales people that use these terms to denote that their product is superior.

Sand Stabilisation
Is a term given to the solidification of sand which produces a stabilising affect.  

Is the grouting of faults in coal mines.  It denotes the solidification of these areas prior  to attending to mining through these areas.

Curtain Grouting
Is the grouting that is done prior to constructing a dam.  It is the process of drilling into rock and pumping in a grout (usually portland cement) to stop water flow below the dam after it is finally filled with water.

Foundation Grouting
Is the same as curtain grouting.

Epoxy Injection
Is the pumping of epoxy resins into cracks in concrete structures.

A term used by "marketing and sales" personnel who are selling grouting ,materials.   It is an attempt by these people to provide an "air of knowledge" about grouting processes.  Generally they are referring to pressure grouting, and many have very little knowledge of the actual processes involved.