MEMBER DIFFERENT IN CONCRETE STRENGTH DISTRIBUTION AND MANUFACTURE THEREOF

摘要

PURPOSE: To obtain a member rational from a structural aspect different in the concrete strength distribution of its cross section by properly using concretes not hardened different in composition such as a water/cement ratio at every positions of the cross section of the member to arrange them to constitute required concrete strength distribution. ;CONSTITUTION: In the case of centrifugal molding, the composition of concrete is changed at every positions of the cross section of a member at the time of centrifugal molding to change the developed strength of concrete. For example, retaining mold rotating circular drums 2 mounted on both ends of the outer peripheral retaining mold 1 of a PCa pillar formed into a hollow square pillar shape are placed on retaining mold rotating drive wheels 3 and a retaining mold rotating wheels 4 and the retaining mold 1 is rotated by the drive wheels 3 and the concrete in the retaining mold is compacted by the centrifugal force generated at this time. The dehydration amount of concrete not hardened is changed by the applying way of centrifugal force and the water/cement ratio in concrete not hardened continuously becomes small. As a result, the developed strength of concrete becomes high from the central part of the cross section of the pillar toward the outside thereof.;COPYRIGHT: (C)1993,JPO&Japio