Lightning protection system for PC buildings

Reinforced concrete (RC) structure buildings constructed using precast concrete (PC) employ mechanical joints to connect the main reinforcing bars within columns. In such buildings, there is generally a void space between the mechanical joints and the main reinforcing bars, or between each reinforcing bar, where no electrical connection exists. Obayashi Corporation have therefore exploited the lattice-shape or grid-like structure of the reinforcing bars to develop lightning connectors, thereby making effective use of the building's characteristics to enable protection from lightning. The main reinforcing bars are electrically connected to joints using an intermediary between the connections, thus creating a number of routes for the lightning current to flow and ultimately delivering a highly reliable lightning protection system. The lightning connector was evaluated by “the Investigation and Research Committee on the Performance Requirements of Down-Conductors Made of Rebar for Lightning Protection” of the Institute of Electrical Installation Engineers of Japan [3]. And the lightning connector meets the requirements for the IEC standard, connection components [5].