Integrity of Shear Connection Mechanisms in Precast Concrete Insulated Wall Panels

预制混凝土保温板通常用作外墙。它们是有利的，因为它们在结构和热效率上是有效的。它们由两层钢筋混凝土组成，环绕着一层绝缘层。混凝土层由称为剪切连接件的纽带连接。在今天使用的大多数面板中，剪力连接件在荷载作用下变形，导致混凝土层之间的相对滑移。与实心面板相比，这种滑移会降低面板的强度和刚度(即，它们在相同的载荷下变形更大)。目前的设计指南中没有考虑滑移；电池板的设计是基于保守的假设和设计师的经验。 随着太阳能电池板因结构和环境载荷的循环而长期退化，滑移预计会增加。在冷热天气中，面板也会因热弯曲而变形。热弯曲会在墙壁之间造成缝隙，降低隔热质量。目前还没有现有的设计技术来预测这些电池板的长期退化和热弯曲。需要进行研究来克服这一知识鸿沟，并确保工程师和从业者能够有效地设计并准确预测这些小组在短期和长期的反应。 拟议计划的长期目标是更好地了解和改善预制混凝土隔热混凝土板在结构和环境荷载下的性能，并有助于优化和耐用结构构件的设计。将开发指南，使工程师和制造商能够第一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，该计划将专注于三个短期目标：(1)通过对面板设计参数进行结构测试，进一步了解预制混凝土保温墙板的短期行为；(2)探索长期影响这些面板的基本机制(循环结构荷载、温度弯曲和环境破坏)；以及(3)开发经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。 该研究项目将培养6名研究生和5名本科生高素质人才，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一知识传授给工程师和建筑业，将使结构和热优化面板得以开发。这些更高效的墙将减少：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.