The surface of concrete structures is subject to abrasion when they are constructed in sea water where ice movement is active. Abrasion occurs due to the friction force between ice sheets and the structure caused by the ice force working on the structure.Over the past ten years we have been conducting experiments with many types of concrete and their possible coating materials to find their characteristics of abrasion due to movements of ice sheets. In this experiment we calculated the abrasion rates (average amount of abrasion per 1 km movement of ice sheets) of various kinds of stone needed to estimate the abrasion amount due to movements of ice sheets which contain sand particles or not, and we also clarified the mechanism of abrasion.

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Ice floes are widely known to abrade surfaces of structures constructed in sea water areas where ice floes move actively.Since both corrosion and abrasion by sea ice cause a decrease in the thickness of the steel of marine structures in frozen sea water areas , differentiating these effects is difficult in practice.We measured thickness of the steel sheet piles used for the side walls of the channel and for the piers of the bridge built over the channel.From the measurements we found the abrasion of the steel by sea ice movements and developed a technique to estimate the abrasion depth.

In constructing an offshore structure in a sea area covered with ice it is necessary to understanding the ice load exerted by drift ice.

If offshore structures are constructed in sea ice regions,wear of the surface of the structures by ice sheet which moves horizontally and vertically by tidal actions must be taken into consideration.The authors have carried out systematic experiments on the abrasion of various materials(various concrete,steel and various coatings)for about ten years.In these experiments,wear tester of reciprocating abrasion type which had been developed by Saeki et al was used.In this paper,the authors clarified the abrasion rate of various kinds of stones(granite,tuff,sandstone and andesite)through systematic experiments.