MANUFACTURING METHOD FOR CONCRETE BLOCK, AND ITS MANUFACTURING FORM

PROBLEM TO BE SOLVED: To eliminate defects such that when a concrete block is manufactured, air bubbles and water bubbles remain unless air generated from the internal surface of the bottom section of the concrete block and an excessive water content or the like are removed, an the quality of this section is reduced. SOLUTION: When the concrete block is manufactured, a frame 22 having grooves is arranged on the internal surface of an internal form 2 which forms the internal surface of the bottom section of the concrete block. In this case, the frame 22 has a plurality of grooves 22a which communicate with the outside of a form 100 being approximately in parallel with the internal surface of the internal form 2, and on which a filter cloth 23 is provided under a state being stretched while a tension is applied. Then, while air and an excessive water content or the like collected on the internal surface of the bottom section are made to bleed into the grooves 22a through the filter cloth 23, concrete in the form is clamped and fixed. Then, an air stream is passed through respective grooves 22a of the frame having grooves, and air and the excessive water content or the like are removed by the passing air stream.