PURPOSE: To positively fix a sleeve material and to provide a reduction in a term of work, leakage prevention, and enhanced appearance.

CONSTITUTION: One end of a female-screwed shaft 5 is fixed, using a nut mounted on one side wall at the sleeve material arrangement position of a skeleton form. A guide 10 is externally engaged with the shaft 5. A real pipe sleeve 4 is inserted in such a manner as to internally engage with the shaft 5 and the guide 10. An end cone 8 allowed to function as a cover is then mounted on the trail end of the real pipe sleeve 4. A locking nut 14 screwed into the end of the shaft 5 presses the real pipe sleeve 4 with the aid of the end cone 8 to eliminate a gap between both the end surfaces of the real pipe sleeve 4 and the internal surface of a beam form 12.