| abstract |
(57) [Summary] [Purpose] A strong block having a complicated three-dimensional structure is molded from an inexpensive material such as coal ash. [Structure] Bottom formwork 11, side formwork 12, top formwork 13 Are provided with ridges 11a, 12a, 13a, respectively, and the cylindrical body 11b is extended from the bottom ridge 11a so that the top mold 13 It is fitted into the through opening 13c. The sleeve portion 13 that slides into the cylindrical body 11b from the raised portion 13a of the top mold 13 b is extended, and the sleeve portion 13b is tapered so as to reduce its diameter downward. |