CONCRETE COMPOSITION FOR HUME CONCRETE PIPE AND PRODUCTION OF CENTRIFUGAL HUME CONCRETE PIPE

摘要

PURPOSE:To produce hume concrete pipes free from float and release on the inner surface by subjecting a concrete composition containing a specific amount of Portland cement and a polyethylene glycol having a specific molecular weight to centrifugal molding. CONSTITUTION:100 pts.wt. Portland cement is blended with 0.005 to 5 pts.wt. polyethylene glycol having 106 to 3,800 molecular weight to give a concrete composition for hume concrete pipe. The concrete composition is mixed with a given amount of an aggregate and optionally another admixture and kneaded in the presence of water. The concrete material is subjected to centrifugal molding. In the operation, water in the material is extremely smoothly transferred by the added polyethylene glycol to promote dehydration. Consequently, molding time is extremely shortened and hume concrete pipes free from float and release on the inner surface are obtained at low cost.