to freely be moved forward and backward by the operation of the hydraulic jack 46 fig1 and 14 illustrate yet another embodiment of the device for breaking concrete structures according to the present invention in this embodiment a hydraulic jack supporting frame 64 freely and liftably suspended by a suspending wire 72 along a beam or column 70 of a concrete structure and a connecting frame 65 freely and liftably suspended by a suspending wire 73 along another beam or column 71 are connected by connecting rods 66 positioned at opposite sides of the two beams or columns 70 71 a loading head 62 adapted to apply concentrated load upon the opposite face of the beam or column 70 is fastened to the end of a freely retractable piston rod 61 of a hydraulic jack 60 connected via oil conduits 67 and 68 to an oil pressure generating and controlling unit 76 the rear end of the hydraulic jack 60 is interlocked with the connecting frame 65 through the supporting member 63 having a greter load receiving area in the diagrams 69 is a metal piece for fastening the suspending wires 72 and 73 and 74 and 75 respectively a thread formed on the connecting rod 66 and a nut screwed on the thread once the supporting frame 64 the connecting frame 65 and the two connecting rods 66 are set around the two columns 70 and 71 spaced by a certain distance from each other as shown in the diagrams this device.