To facilitate connection of reinforcements by forming a through hole in which reinforcements can be inserted and forming a hardener injection hole communicating with the central part of the through hole from a butt end face where the through hole is opened and forming an air vent hole communicating with the through hole from the butt end face.

A nearly hexagonal columnar joint metal fitting 10 is formed with a metallic or synthetic resin material. A through hole 13 formed to communicate with both butt end faces 11, 12 and provided with a screw at the inside wall face is bored at the center part of the joint metal fitting 10. And further, resin injection holes 14, 15 communicating with the central part of the through hole 13 from the butt ends 11, 12 where the through hole 13 is opened, and air vent holes 16a, 16b communicating with the through hole 13 from the butt end faces 11, 12 are formed. The end of reinforcement 25 is inserted from the butt end face 12 side to the central part of the through hole 13. And the body 21 of a seal member 20 is inserted from the butt end face 11 side to closely stick the sealing part 22 to the butt end face 11. A resin 26 is injected into the through hole 13 from a hardener injection hole 15 and hardened. Accordingly, safety of traffic and works can be kept.