3D-AM Thermally Smart Composites for Highly Sustainable and Energy Efficient Building Design and Retrofitting

减少建筑行业与能源相关的二氧化碳排放，对于遏制近期全球平均二氧化碳含量前所未有的增长至关重要。根据《2020年全球建筑现状报告》，该行业占全球能源和工艺相关二氧化碳排放量的近38%。特别是，水泥生产和建筑及其业务阶段的能源使用，以及在服务生命周期后处置拆除废物，是与建筑部门有关的主要排放源。尽管对环境造成了严重的影响，但几乎所有的建筑项目仍然依赖于几十年前的、不可持续的建造和改造方法，这些方法需要用新的方法进行更新，以推动建筑行业走向更大的可持续性。为了消除胶凝混凝土对环境的影响，限制建筑物的能源使用，同时适当地回收建筑和拆除废物（CDW），本研究提出开发新型、热智能、环保和节能的CDW基地聚合物复合材料，这种复合材料可以通过三维增材制造（3D-AM）加工技术很容易地用作新建筑和现有建筑的结构和绝缘/改造材料。预计它们将具有相变材料（PCM）在增强存储容量方面的优势，完全稳定且PCM防泄漏，通过导电填料优化设计以最大化其导热性，并具有高机械和耐用性能。此外，它们将完全基于CDW材料，通过最大限度地包含它们作为粘合剂，骨料和硬化剂。因此，所得到的热智能复合材料将通过满足增材制造所需的流变、触变、机械和打印性能，为3D打印过程进行优化。目标地聚合物复合材料将通过增强建筑围护墙和改造/涂层技术来适应任何建筑设计和改造应用。这些创新系统的最终性能评估将在各种冷热环境下的实验室规模原型上进行，以确保实现目标热性能。此外，通过在整个计划任务中进行环境和成本评估分析，将确保从材料合成到开发的复合材料的最终应用的可持续性和成本效益。拟议研究的结果将大大减少加拿大和世界各地建筑部门的能源消耗，并为大量回收填埋的CDW材料找到切实可行的生态解决方案。这种节能预计将成为建筑行业脱碳、减少全球二氧化碳排放和相关气候变化影响的重大进步。

Reducing energy-related CO2 emissions from the construction sector is critical to curbing the unprecedented recent increase in the global mean abundance of carbon dioxide. According to the 2020 Global Status Report for Buildings and Construction, the sector accounts for almost 38% of energy- and process-related CO2 emissions worldwide. In particular, cement production and energy use in construction and its operational phases, and the disposal of demolition waste after the service life cycle, are the major sources of emission related to the building sector. Despite the severe environmental impact, almost all construction projects still rely on decades-old - and unstainable -- methods of construction and retrofitting, which need to be updated with novel methodologies to advance the construction industry toward greater sustainability. To eliminate the environmental impact of cementitious concretes and limit the energy use of buildings while properly recycling construction and demolition wastes (CDW), this research proposes to develop novel, thermally-smart, eco-friendly and energy-saving CDW-based geopolymer composites that can be easily used as structural and insulation/retrofitting materials in new and existing buildings via three-dimensional additive manufacturing (3D-AM) processing techniques. It is expected they will have the advantages of phase change materials (PCMs) in terms of enhanced storage capacity, be completely stable and PCM leak-proof, be optimally designed with conductive fillers for maximizing their thermal conductivity and have high mechanical and durability performance. Further, they will be based entirely on CDW materials through their maximized inclusion as binders, aggregates and hardeners. Hence, the resulting thermally smart composites will be optimized for the 3D printing process by fulfilling the required rheological, thixotropic, mechanical and printability properties of additive manufacturing. The targeted geopolymer composites will be developed to suit any building design and retrofitting application through reinforced building envelope walls and retrofitting/coating techniques. The final performance assessment of these innovative systems will be undertaken on laboratory-scale prototypes under various hot and cold environments to ensure that the targeted thermal performances are achieved. Also, sustainability and cost effectiveness will be ensured from material synthesis to the final application of the developed composites by performing environmental and cost assessment analyses throughout the planned tasks. The outcome of the proposed research will be to greatly reduce energy consumption by the building sector in Canada and around the world, and to find practical, ecological solutions for the mass recycling of landfilled CDW materials. Such energy savings are expected to be a significant advancement toward decarbonizing the construction industry and reducing global CO2 emissions and related climate change impact.