To simplify construction and reduce a cost, by confirming a construction method of a down-conductor while evaluating an electrical resistance value of a main reinforcing steel.
A first target electrical resistance value R1 around a serial connection part T and a second target electrical resistance value R2 of the entire one main reinforcing steel 4, from an upper wend part 4a to a lower end part 4b including the serial connection part T, are set for a lightening down-conductor 1. At construction of a post 3, the first electrical resistance value of the serial connection part T is measured. If the first electrical value is larger than the first target electrical resistance value R1, the end parts of the main reinforcing steel 4 at the serial connection part T are communicated to each other through an electric wire. Then, at the completion of the construction of the post 3, the second electrical resistance value around one main reinforcing steel 4 arranged in the post 3 is measured. If the measured second electrical resistance value is larger than the second target electrical resistance value R2, lower end parts 4b and 4b as well as upper end parts 4a and 4a of two main reinforcing steels 4A and 4B are communicated each other through an electric wire.
Tadashi Takahashi
Takashi Watanabe
Masakazu Aoyama