Concrete is a rigid material placed at all sorts of thicknesses from 4” to 14” and even thicker. No matter the amount or thickness, a diamond tipped blade is most commonly used to cut through the rigid gritty 4000psi+ compressive strength material. Concrete being a dry material made up of sand, aggregate, and cement can kick up loads of dust when being cut. Most walk behind commercial gas powered saws have a connection for a hose or water source to douse the blade with water as it cuts, both cooling the blade for longer life and also eliminating most of the dust created.
Concrete has excellent compressive strength but relatively poor tensile strength, which is one reason reinforcing mesh or rebar is often put in it. As one might imagine, steel makes cutting through concrete more difficult and less productive, requiring longer time periods and higher costs.
There are many needs for cutting concrete pavement or sidewalks but the most common need is for repair or replacement work for deteriorated pieces or pieces with deteriorated joints. The standard cut-off saw can only cut 3-4″ through concrete, heavy duty walk behind saws are required far anything thicker. Full depth concrete cutting is commonly done by a specialty subcontractor who knows what to expect and can handle many of the unforeseen challenges that may come with the task.