The sensitivity of structures to climate and environmental actions

***目的：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害的影响。具体而言，该计划旨在建立结构暴露于侵蚀剂的模型，并了解其空间和时间变化，以改进现有的降解进化模型。***拟议的研究包括三个主要的科学阶段。本研究的第一阶段包括收集现有数据。气象站和冬季道路测量员的组织是这些活动的基础。这项研究将涵盖加拿大的各个地区，特别是在每个省会和魁北克省、安大略省和不列颠哥伦比亚省的其他城市。***本研究第二阶段为局部结构暴露观察。结构土木电子学（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）和取样岩心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，例如暴露于死水、飞溅和含盐雾中。将研究积雪对道路边缘清除积雪和风力作用所沉积的结构的影响，以确定这些积雪是否作为水和除冰产品的绝缘体。如果是这样的话，雪融化过程中的干燥和湿润可能会导致混凝土覆盖层中的氯离子快速转移。***本研究的第三阶段是利用非线性数值模型，如“TransChlor”（TC）模型，分析暴露对结构构件退化的影响。“TC”考虑了热交换、水的扩散输送和毛细作用以及氯离子在混凝土覆盖层中的迁移。“TC”与比较所研究的不同地区的气候和环境行为的概率方法有关。这个阶段很重要，因为它可以突出结构损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扩散。* * *

***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.* **