The purpose of this report is to increase the crushing efficiency of a concrete structure by means of an edge excavation system using a ripping disc cutter bit. A cutting drum mounting a roller cutter bit and two series of ripping disc cutter bit was used for a model test using several specimens of concrete. As a result, it was observed that the maximum horizontal and vertical excavation force, and the maximum torque acting on a cutting drum and the excavation power increased with the increment of uniaxial compressive strength of concrete and depth of cutting. The specific cutting energy decreased with the increment of cutting depth in the range of high efficiency of a ripping disc cutter bit, but increased with the increment of the uniaxial strength of concrete.