| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a composition for extrusion molding, capable of improving the fluidity of a cemental composition and having excellent moldability. SOLUTION: This cemental composition for molding is obtained by adding a cement admixture to a composition for molding containing at least a cement. The admixture has 0.5-300Pa value of shear stress A at 10s<-1> in a test on flow characteristics carried out by stirring a mixture of 27.5 pts.wt. cement with 27.5 pts.wt. silica sand No.7, 1.1 pts.wt. pulverized pulp having 3mm size, 0.1 pt.wt. admixture and 20 pts.wt. water for 60min and increasing the shear rate from 0 to 100s<-1> at a constant rate per min by using a viscometer. The admixture includes hydroxyalkyl alkyl celluloses (hydroxypropyl methyl cellulose or hydroxyethyl methyl celluose) and hydroxyalkyl celluloses (hydroxyethyl cellulose). The admixture may be used with a surfactant in combination.</p> |
