Hideki NARITA

A Study of the Relation between Rust and Environment of the Corrosion on BridgesUsed Weathering Steel in Niigata

Masatsugu NAGAI Eiji IWASAKI

In Niigata, the weathering steel has not been used at the location where the distance
from the seashore is less than 20 kilometers, except that salt floating in the air is less
than 0.05 mdd. However, there are a lot of weathering steel bridges in the area within
20 kilometers from seashore and the state of rust has not been observed.
Therefore, in this study the relation between rust and environment of the corrosion is
observed by measurement of floating salt, adhered salt on the surface on the steel and
thickness of rust to use of plan for construction of bridge in the future.
The following results are obtained by the observation;
* The state of rust is different in the outside girder and inside girder.
* The state of rust of inside girder is worse than the outside girder.
* The lower flange of inside girder is worst state of rust.
* The direction of the wind affects the state of rust.
* The thickness of rust increases as adhered salt increases.