CENTRIFUGAL MOLDING ASSISTANT, CONCRETE, METHOD FOR PRODUCING HUME PIPE, AND HUME PIPE

摘要

PPROBLEM TO BE SOLVED: To provide a centrifugal molding assistant which can make Hume pipe production efficient, is useful for the protection of global environment because of no formation of whitewash and consequently no necessity of being buried, and does not influence the compressive strength and external pressure strength of a Hume pipe even when the water/cement ratio of the pipe is not lowered because of absence of dehydration, to provide concrete, to provide a method for producing a Hume pipe using the same, and to provide a Hume pipe. PSOLUTION: What is provided is: a centrifugal molding assistant mainly consisting of bentonite and a polyvinyl alcohol having an average degree of polymerization of 2,000 or lower; a centrifugal molding assistant wherein the polyvinyl alcohol is a partial saponificate; a concrete comprising cement, aggregate, a water reducing agent, water, and the centrifugal molding assistant; concrete wherein the bentonite is used in a quantity of 1 to 12 kg/mSP3/SPper unit volume of concrete, and the polyvinyl alcohol partial saponified material is used in an amount of 0.5 to 10 pts. per 100 pts. bentonite; concrete further comprising an expansion material and/or a high-strength admixture; a Hume pipe using the concrete; and a method for producing the Hume pipe. PCOPYRIGHT: (C)2006,JPO&NCIPI