The sensitivity of structures to climate and environmental actions

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Objectives: The general objective of the research program is to study the influence of weather conditions and the presence of chemicals on roadways to the damage observed on road structures in Canada. Specifically, the program aims at the modelling of structure exposure to aggressive agents and to understand the spatial and temporal variability in order to improve on the existing models of degradation evolution. The proposed research consists of 3 major scientific phases. Phase 1 of this research involves the collection of existing data. Meteorological stations and the organization of road-surveyors in the winter are the basis of these activities. This research will cover various regions in Canada, particularly in each provincial capital and in other cities in Quebec, Ontario, and British Columbia. Phase 2 of this research is to observe the local structure exposure. Structural civionics (an emerging discipline involving the combination of civil engineering, with current application in the structural health monitoring of civil structures) and sample cores would allow for the collection of climatic and salt data on roadways and structures. Exposure zones will be proposed from these data, such as exposure to stagnant water, splashing, and salt laden mist. The impact of snow accumulations on structures deposited by snow-clearing on the edge of roadways and also by wind action will be studied to determine if these accumulations act as an insulator to water and de-icing products. If this is the case, the drying, then the wetting during snow melt, could cause fast chloride ion transfer in the concrete cover. Phase 3 of this research is the analysis of the exposures impact on the degradation of structural elements by using nonlinear numerical models, such as the "TransChlor" (TC) model. "TC" takes into account thermal exchange, water transport by diffusion and capillarity and chloride ions migration in the concrete cover. "TC" is associated with a probabilistic approach that compares the climatic and environmental actions of the different regions studied. This phase is important because it allows for highlighting the sensitivity of the structural damage to climatic and environmental factors. This sensitivity is based on wetting-drying periods, regional humidity, and the spreading of de-icing product.