Integrity of Shear Connection Mechanisms in Precast Concrete Insulated Wall Panels

预制混凝土保温板常用作外墙。它们是有利的，因为它们是结构和热效率。它们由两层钢筋混凝土层围绕着一层绝缘层组成。混凝土层是用一种叫做剪切接头的纽带连接起来的。在今天使用的大多数面板中，剪切连接件在荷载作用下变形，导致混凝土层之间的相对滑移。相对于实心面板，这种滑移降低了面板的强度和刚度（即它们在相同载荷下变形更多）。在当前的设计指南中没有考虑滑移；面板的设计是基于保守的假设和设计师的经验。******由于循环结构和环境载荷，面板在长期内降解，滑移预计会增加。在炎热和寒冷的天气里，面板也会因热弯曲而变形。热弯曲在墙壁之间产生间隙，降低了保温质量。没有现有的设计技术可以预测这些面板的长期退化和热弯曲。需要进行研究以克服这一知识差距，并确保工程师和从业人员能够有效地设计和准确地预测这些面板的短期和长期响应。******该计划的长期目标是更好地了解和提高预制混凝土隔热混凝土板在结构和环境载荷下的性能，并为优化和耐用结构构件的设计做出贡献。将开发指南，使工程师和制造商能够首次准确地设计和分析受结构和环境载荷影响的面板。为了实现这一目标，该计划将侧重于三个短期目标：(1)通过对以前未解决的面板设计参数进行结构测试，进一步了解预制混凝土隔热墙板的短期行为；(2)探索长期影响这些面板的基本机制（循环结构载荷、热弯曲和环境破坏）；(3)建立经试验结果验证的模型，预测这些面板的短期和长期结构响应。******本研究计划将培养6名研究生和5名本科生的高素质人才，将他们的研究成果和专业技能发展成为预制混凝土保温墙板和钢筋混凝土结构领域的专家。完成研究目标并将这些知识传递给工程师和建筑行业将允许开发结构和热优化面板。这些更高效的墙壁将减少：制造和运输过程中的温室气体排放，建筑物居住者的供暖和制冷成本，以及维护建筑物外部的成本。

Precast concrete insulated panels are commonly used as exterior walls. They are advantageous as they are structurally and thermally efficient. They consist of two reinforced concrete layers that surround a layer of insulation. The concrete layers are connected with ties called shear connectors. In most panels used today, shear connectors deform under load resulting in relative slip between the concrete layers. This slip reduces panel strength and stiffness (i.e. they deform more under the same load) relative to solid panels. Slip is not accounted for in current design guides; panels are designed based on conservative assumptions and designer experience.******Slip is expected to increase as panels degrade over the long term from cycling structural and environmental loads. Panels also deform from thermal bowing on hot and cold days. Thermal bowing creates gaps between walls and reduces insulation quality. There are no existing design techniques that predict long term degradation and thermal bowing in these panels. Research is required to overcome this knowledge gap and ensure that engineers and practitioners are able to efficiently design and accurately predict the response of these panels over the short and long term.******The long term objective of the proposed program is to better understand and improve the performance of precast concrete insulated concrete panels subject to structural and environmental loads and contribute toward the design of optimized and durable structural members. Guides will be developed that will allow engineers and manufacturers to accurately design and analyze panels subject to structural and environmental loads for the first time. To accomplish this, the program will focus on three short term objectives: (1) develop further understanding of the short term behaviour of precast concrete insulated wall panels by conducting structural tests on panel design parameters that have not been addressed before; (2) explore fundamental mechanisms (cyclic structural loading, thermal bowing, and environmental damage) that affect these panels over the long term; and (3) develop models validated by experimental results that predict the structural response of these panels over the short and long term.******This research program will train 6 graduate and 5 undergraduate Highly Qualified Personnel to apply their research findings and professional skills development to become experts in the field of precast concrete insulated wall panels and reinforced concrete structures. Completing the research objectives and transferring this knowledge to engineers and the construction industry will allow structurally and thermally optimized panels to be developed. These more efficient walls will reduce: greenhouse gas emissions during fabrication and transportation, heating and cooling costs for building occupants, and the costs of maintaining building exteriors.