| 摘要 |
PROBLEM TO BE SOLVED: To require no skill and shorten manufacturing time and further enable avoiding risks during an operation by charging concrete into a form which is rotated at a low velocity and cutting the concrete to he specified thickness and further, tightly solidifying the concrete by centrifugal molding, when a Hume concrete pipe is manufactured by reducing the generation of lime wash or preventing it from being generated. SOLUTION: Concrete is charged into a form to spread it over the entire length of a pipe while the form is rotated at such a low velocity that the concrete is allowed to stick flat to the inner wall of the form, and the excess thick concrete is removed at this point of time. For example, a steel bar of the same length as or longer than the length of the pipe or the like is pressed using the edge of both ends of the form, while the form is rotated at a low velocity and the excess concrete which is swollen to the side of the rotating direction is removed using a hooked bar or the like. Thus it is possible to manufacture a Hume concrete pipe of a specified thickness through molding at a single round of rapid rotation by cutting the excess concrete before initiating the centrifugal molding process.
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