METHOD FOR MANUFACTURING CONCRETE PRODUCT

PROBLEM TO BE SOLVED: To provide a method for manufacturing a concrete product by centrifugal molding capable of preventing the concrete product molded by the centrifugal molding from cracking by effectively applying a contraction reducing agent to prevent the concrete product from cracking. SOLUTION: The method for manufacturing for the concrete product in which the concrete product is manufactured by holding concrete in a mold, and the centrifugal molding executing low speed rotation molding for rotating the mold such that the centrifugal force becomes the range of 1 to 2 G, by middle speed rotation molding for rotating the mold such that the centrifugal force becomes the range of 5 to 15 G after the low speed rotation molding, and high speed rotation molding for rotating the mold such that the centrifugal force becomes the range of 20 to 40 G after the middle speed rotation molding, is characterized in that the contraction reducing agent is sprayed on the surface of the concrete in the mold after holding the concrete in the mold and before starting the high speed rotation molding. COPYRIGHT: (C)2010,JPO&INPIT