PURPOSE: To reduce labor and time required for bending by easily joining main reinforcement and sheared reinforcing bars together and bending each sheared reinforcing bar at the same time.

CONSTITUTION: Plural sheared reinforcing bars 13 are arranged horizontally in parallel at specified intervals mutually. The plural main reinforcements 11A-12C are mounted on the respective sheared reinforcing bars 13 in parallel at specified intervals so as to orthogonally cross to auxiliary reinforcing bars 14. The crossing parts between the respective auxiliary reinforcing bars 14 and the respective main reinforcements 11A-12 are joined together by binding, etc. The respective sheared reinforcing bars 13 are bent orthogonally at the crossing parts to the main reinforcements 11A, 11C, 12A and 12C and formed into an annular shape. Both ends 13a and 13b of each sheared reinforcing bar 13 are joined together mutually.