PURPOSE: To perform a centrifugal molding of concrete under excellent workability and productivity by using a water reducing agent with high stability and keeping sufficient flowability at a less usage of the water reducing agent, in the centrifugal molding by adding the water reducing agent and a slag solid content reducing agent to the concrete.
CONSTITUTION: In the centrifugal molding of concrete, a copolymer of a (meth) acrylic acid (salt) and a 3-(meth)aryloxy-2-hydroxy-1-propanesulfonic acid as the water reducing agent and a poly(meth)acrylamide partially hydrolyzed compound (salt) as the slag solid content reducing agent are both added. Thus, sufficient flowability can be kept at about half of the addition quantity of the water reducing agent against the use quantity of the conventional water reducing agent (naphthalenesulfonic acid/formaldehyde condensation product), and also reduction of the slag is contrived and the workability in the centrifugal molding, productivity and the finished property of the inside surface of the product formed pipe are imporved.
KUBO MICHIYO
OKAMOTO TAKASHI
YAMAMOTO KAZUMASA
TAKAHASHI KUNIHIRO
ICHIHASHI YOSHIO
