The sensitivity of structures to climate and environmental actions

目标：该研究计划的总体目标是研究天气条件和道路上化学物质的存在对加拿大道路结构所观察到的损坏的影响。具体地说，该计划旨在对结构暴露于侵袭性毒剂的模型进行建模，并了解其空间和时间变异性，以改进现有的退化进化模型。 这项拟议的研究包括三个主要的科学阶段。这项研究的第一阶段涉及现有数据的收集。气象站和冬季道路测量员的组织是这些活动的基础。这项研究将覆盖加拿大的不同地区，特别是在每个省会以及魁北克、安大略省和不列颠哥伦比亚省的其他城市。 本研究的第二阶段是观察局部结构暴露情况。结构土壤学(一门新兴学科，涉及土木工程与目前在土木结构结构健康监测中的应用相结合)和样品岩芯，将允许收集有关道路和结构的气候和盐分数据。将根据这些数据提出暴露区域，如接触积水、飞溅和充满盐雾的环境。将研究积雪对道路边缘清雪和风力作用所沉积的建筑物的影响，以确定这些积雪是否起到水和除冰产品的绝缘作用。如果是这种情况，那么在积雪融化过程中的干燥和潮湿，可能会导致混凝土保护层中氯离子的快速转移。 本研究的第三阶段是利用非线性数值模型分析暴露对结构构件退化的影响，如TransChlor型(TC)模型。“TC”考虑了混凝土保护层中的热交换、水的扩散和毛细迁移以及氯离子的迁移。“TC”与一种概率方法有关，该方法比较所研究的不同地区的气候和环境活动。这一阶段很重要，因为它可以突出结构破坏对气候和环境因素的敏感性。这种敏感性取决于干湿周期、区域湿度和除冰产品的铺展情况。

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.