Abstract
Many viaducts of highway in urban area are covered by bridge enclosure for beautiful view. In order to evaluate the possibility of omitting the repainting of steel girders inside the bridge enclosure, the corrosivity inside and outside the bridge-enclosure of viaducts of Osaka-Kobe highway was investigated with ACM (Atmosphere Corrosion Monitor) sensors, thermo-hygrometers, steel coupons and measurement of pollution. The results showed that rainwater and pollution could enter through the gaps between the panels of the bridge enclosure and stay at the surface of steel girders, which induced the rusting of steel girders. It is proposed in present study that the tightness of bridge enclosure should be increased for improving the rusty resistibility and thus omitting the repainting of steel girders inside the bridge enclosure.
