Integrity of Shear Connection Mechanisms in Precast Concrete Insulated Wall Panels

预制混凝土隔热板通常用作外墙。它们的优点在于结构和热效率高。它们由两层钢筋混凝土层组成，周围一层绝缘层。混凝土层通过称为剪力连接器的拉杆连接。在当今使用的大多数面板中，剪力连接件在负载下变形，导致混凝土层之间产生相对滑动。相对于实心面板，这种滑移降低了面板的强度和刚度（即，它们在相同负载下变形更大）。当前的设计指南中没有考虑滑移；面板的设计基于保守的假设和设计师的经验。*****随着面板因循环结构和环境负荷而长期退化，滑移预计会增加。在炎热和寒冷的日子里，面板也会因热弯曲而变形。热弯曲会在墙壁之间产生间隙并降低隔热质量。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。需要进行研究来克服这一知识差距，并确保工程师和从业人员能够有效地设计和准确预测这些面板在短期和长期的响应。******拟议计划的长期目标是更好地理解和提高预制混凝土隔热混凝土面板在结构和环境载荷下的性能，并为优化和耐用的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承受结构和环境载荷的面板。为了实现这一目标，该计划将重点关注三个短期目标：（1）通过对以前未解决过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) 开发通过实验结果验证的模型，预测这些面板的短期和长期结构响应。 *****该研究计划将培养 6 名研究生和 5 名本科生高素质人才，以应用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有助于开发结构和热优化的面板。这些更高效的墙体将减少：制造和运输过程中的温室气体排放、建筑居住者的供暖和制冷成本以及维护建筑外部的成本。

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.