This paper provides the rationale and proposed conceptual design of a test setup to induce and monitor the effects of ice wear and abrasion on marine concrete. Concrete wear from ice contact is a prevalent concern that requires standardized examination. Particular attention will be paid to loss of concrete due to simulated pack-ice interaction situations, as seen in ice prone environments. Opportunities for concrete submergence and long duration testing are the key features of the proposal. Construction of the proposed setup will occur immediately upon completion of the feasibility study.
Pack-ice interactions with marine structures are characterized by long duration loading that can be applied by normal forces, shear forces or a combination of the two. The continuous frictional interaction between the ice and the structure results in gradual abrasion of the concrete. This is in contrast to other forms of ice interaction such as infrequent iceberg loadings that exhibit brief, but high-impact, interactions. Structures like Atlantic Canada's Confederation Bridge in the Northumberland Strait can be exposed to approximately 1000km of ice drift per month (Brown et al, 2001) during the January-April winter season. As seen in Figure 1, ice movement against the bridge piers over time has worn away the cementitious material. The gradual wearing process exposes the aggregate, increases concrete porosity and reduces the durability and integrity of the structure over time. This poses a risk to any marine concrete structure including bridge piers, lighthouses and offshore gravity based drilling and production structures that are located in ice prone environments.
Existing conventional test setups are most often borrowed from other disciplines in material testing (Fosså, 2007). However, concrete surfaces are porous, rough and non-uniform, therefore the interaction between ice and concrete poses an even greater challenge than most materials. In order to make progress with this problem, testing must be completed to specifically isolate the abrasive effects of ice. Detailed research must be conducted into the roles of pressure, sliding velocity, distance, environmental conditions and the pre- and post- contact surface characteristics of both the ice and concrete.
