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品的存在对加拿大道路结构损坏的影响。具体而言，该计划旨在模拟结构暴露于侵略性试剂，并了解空间和时间的变化，以改善现有的退化演变模型。 该研究包括三个主要的科学阶段。本研究的第一阶段涉及收集现有数据。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，特别是在每个省会城市和其他城市在魁北克，安大略和不列颠哥伦比亚省。 本研究的第二阶段是观察局部结构暴露。结构民用电子学（一门新兴学科，涉及土木工程的结合，目前应用于土木结构的结构健康监测）和样品芯将允许收集道路和结构的气候和盐数据。将根据这些数据提出暴露区域，例如暴露于积水、飞溅和含盐雾。将研究积雪对道路边缘除雪和风力作用所沉积结构的影响，以确定这些积雪是否可作为水和除冰产品的绝缘体。如果是这种情况，雪融化期间的干燥和湿润可能会导致氯离子在混凝土保护层中快速转移。 本研究的第三阶段是使用非线性数值模型，如“transChlor”（TC）模型，分析暴露对结构元件退化的影响。“TC”考虑了混凝土保护层中的热交换、扩散和毛细作用引起的水迁移以及氯离子迁移。“TC”与一种概率方法有关，这种方法比较所研究的不同区域的气候和环境作用。这一阶段很重要，因为它可以突出结构损坏对气候和环境因素的敏感性。这种敏感性是基于干湿期，区域湿度，和除冰产品的传播。

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.