An angle grinder, fitted with either abrasive wheels or diamond tipped blades, may be used to form a shallow cut into concrete. There are hydraulic and air driven machines, but the normal is 110 volt electric. These machines usually run dry. Cutting is restricted to a depth of approximately 150mm. These tools are efficient in brick and un-reinforced concrete but slow on reinforced concrete.
Further information may be obtained from the Drilling and Sawing Association