An Investigation of Damage due to Chloride Attack in Reinforced Concrete Framed Housing in Okinawa　－Awase, Tohashina and Ueda Prefectural Housing－

摘要

The authors investigated damage and deterioration due to chloride attack in Awase, Tohashina and Ueda Prefectural Housing, which were built with reinforced concrete (R/C) framed structure about 20 years ago in Okinawa. Such investigations have been carried out plentifully in Okinawa until today. According to these investigations, the following two major points have been already indicated. 1) Sea sand was used in the concrete of housing as the fine aggregate without removing salt. 2) Okinawa is located in the semitropical region under chloride attack environment. From above viewpoints, it is clarified that the damages and cracks due to corrosion of reinforcing steel bars are subjected to R/C structures in Okinawa. These facts are also confirmed through this investigation. Nowadays the durability of R/C structures in Okinawa has been surely improved, however it must be further improved.