| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a concrete product having a hollow part capable of reducing costs of a form for manufacturing and saving labors without using a high-priced core member in which an enlarging/ contracting mechanism for forming the hollow part of the concrete product having the hollow part such as a culvert block and the like is provided. SOLUTION: A resin pipe is used as a core member and installed in a form. Concrete is cast therein to be compacted and cured with steam. A product is taken out from a steam curing tank, the manufacturing form is opened and the concrete product is released from the form while the resin pipe is being installed as it is. A temperature of the concrete product is lowered near to ordinary temperature, the resin pipe of which the diameter is shrunk is pulled out and used again as the core member. Thus, the method for manufacturing the concrete product having the hollow part is constituted. COPYRIGHT: (C)2003,JPO |
