The durability of concrete structures in cold snowy regions such as Hokkaido is significantly reduced by frost damage, as well as by combined deterioration resulting from frost and salt action. However, since no methods have yet been established for quantitative evaluation of such combined deterioration, reductions in durability and deterioration conditions in actual environments cannot be evaluated quantitatively.

The purpose of this study was to enable rational durability design for improved resistance to frost damage and combined deterioration in actual environments by establishing a deterioration prediction method. This approach is based on the relationship between frost damage and combined deterioration in cold snowy areas and other influences as clarified by laboratory/exposure tests and field surveys.

As outlined above, concrete structures in cold snowy regions face severe environments of frost damage and combined deterioration caused by frost and salt action, meaning that a variety of measures to improve durability are necessary when new concrete structures are built.

The purpose of this study was to enable reduction for the life-cycle costs of infrastructure through cold-region technological development to resist frost damage and combined deterioration caused by frost and salt action as seen in cold snowy regions.