To manufacture a curved concrete form easily by filling expandable resin in a metal mold and foaming it, releasing the mold after form self-holding property is revealed, and making external force act upon the mold-released concrete form made of a resin foam body so as to be formed into specified shape.
A recessed part with the outside shape of a natural stone inverted is formed at an expandable resin concrete form 10', and a joint part of piled stone pattern is further formed in such a way as to partition the recessed part. The opposite side of the joint part is made a cavity 23. Thickness is thereby increased and the increase of cooling time is prevented at the internal molding. The expandable resin concrete form 10' is manufactured by filling preliminary expandable resin grain into a metal mold and foaming it. In this case, a resin film is manufactured by applying resin to the surface of the metal mold and transferring the surface state, and the metal mold is manufactured on the basis of the resin film so as to form a protruding part at the metal mold.
KAWAI TAMOTSU
FUKAZAWA YUKIO
NAT MARINE PLASTIC