PURPOSE: To better and rapidly compact as compared with prior art by reciprocating a compacting motion under a direction control, including a first component transferring a concrete mixture in a molding flow direction and a second translational component perpendicular thereto.

CONSTITUTION: When a drawing rod 10 is operated by a hydraulic cylinder 11, components supported by a linkage 18 for supporting a drive shaft 7, a supply auger 5 and a core-forming mandrel 6 are forcibly advanced and retracted, that is the components are advanced and retracted while the linkage 18 is moved in both vertical directions. Thus, concrete mixture in an extruding section receives a compacting motion controlled in two directions. When a clamp lever of the linkage 20 reciprocates a mold top plate 16, similar compacting motion is conducted at the plate 16 supported by the linkage mechanics 19.1, 19.2.