PURPOSE: To improve working efficiency by screwing a main reinforcement joint metal fitting having a screw joint in the upper part and a sleeve joint in the lower part to a main reinforcement, and integrating it into the main reinforcement to connect a column buried in a PC column.

CONSTITUTION: A main reinforcement joint metal fitting 1 having a screw part 1a in the upper part and a sleeve part 1b in the lower part is formed, and the lower end of a main reinforcement 2a which is a screw reinforcement to be buried in a PC column A inner part is screwed to the screw part 1a. Further, a lock nut 3 preliminarily screwed to the end part of the main reinforcement 2a is fastened to introduce an axial tension to the main reinforcement 2a. Then, a mortar injection hole 1c and a mortar discharge hole 1d are bored in the lower part of the side wall of the sleeve part 1b, and mortar 4 is charged through the mortar injection hole 1c. Thus, the force added to the main reinforcement can be more efficiently transmitted.