Regenerative 3D printed cementitious skins for building components (Re3DSkin)

最近的研究报告称，50%的修复混凝土在几年后再次失效（25%在5年内修复，75%在10年内修复，95%在15年内修复），导致重复和昂贵的干预措施，材料消耗和运营碳足迹。强调零维护或最低维护的新战略对于减少该行业的运营碳足迹和实现英国的净零目标至关重要。自修复胶凝复合材料（SHCC）是传统混凝土的有趣替代品。它们含有矿物或生物制剂，与从裂缝中渗透的水反应，产生化合物，密封开口，在严重损坏发生之前修复材料。由于与生产过程和裂纹位置相关的不确定性，文献中的主要方法是在大量组件中使用自愈剂的均匀部署。然而，研究指出了与在建筑部门实施自愈材料有关的几个问题，其中包括材料成本的初始投资。Re3DSkin提出了组件部署策略和功能的转变-使用现代构造方法-能够在表层选择性沉积自修复剂，并根据组件表面每个部分开裂的可能性和程度定制可变浓度。这表层作为一个优化的再生皮肤，以提高资产的性能。3d打印技术可以提供所需的沉积控制和精度，以优化层的细观结构和厚度，通过在线添加添加剂促进可变放置。Re3DSkin的广泛的科学目标是：(1)适应3d打印工艺沉积表面层具有可变的自愈剂浓度，并提高分布精度和准确性；(2)了解3DP层厚度和可变沉积对自愈机制和效率的影响；(3)比较具有可变药剂浓度层的组件与具有均匀自愈剂的等效组件的自愈机制和材料效率；(4)通过使用该解决方案生产世界上第一个全尺寸建筑组件，在实验室和工业中评估和演示新策略的可行性。Re3DSkin将通过延长使用寿命来增强新建和现有资产的弹性，并解决英国老化资产的关键脆弱性。成熟的解决方案可以减少劳动密集型的维修和维护，减少对日益稀缺的熟练劳动力的依赖。Re3DSkin的研究结果还可以减少SHCC中碳密集型材料的使用，以及在资产的整个生命周期内对修复材料的总体需求。Re3DSkin的成果将有助于提高建筑行业的生产力、可持续性和国际竞争力。

Recent studies have reported that 50% of repaired concrete fails again after a few years (25% within 5 years of repair, 75% within 10 and 95% within 15), resulting in recurring and costly interventions, material consumption and operational carbon footprint. New strategies, emphasizing zero- or minimum-maintenance, are vital to reduce the sector's operational carbon footprint and meet the UK net-zero target.Self-healing cementitious composites (SHCC) are an interesting alternative to conventional concrete. They contain mineral or biologic agents that react with water percolating through cracks to produce compounds that seal openings and heal the material before significant damage occurs. The dominant approach in the literature uses a uniform deployment of self-healing agents in a significant volume of the components due to uncertainties associated with the production process and crack positions. Nevertheless, research has pinpointed several issues associated with the implementation of self-healing materials in the construction sector and, among them, the initial investment in material cost. Re3DSkin proposes a shift in the deployment strategy and functionalisation of components - using modern methods of construction - to enable selective deposition of self-healing agents in a superficial layer with a variable concentration tailored to the likelihood and degree of cracking in each portion of the component's surface. This surface layer acts as an optimised regenerative skin to enhance the asset's performance. 3DP technology can offer the required deposition control and accuracy to optimise the layer's mesostructure and thickness, facilitating variable placement via in-line admixture addition. Re3DSkin's broad scientific objectives are to: (1) adapt the 3DP process for deposition of surface layers with variable self-healing agent concentration, and with enhanced distribution precision and accuracy; (2) understand the influence of 3DP layer thickness and variable deposition on the self-healing mechanism and efficiency; (3) compare the self-healing mechanism and material efficiency of components with a layer of variable agent concentration to equivalent components with uniform self-healing agents across the entire volume and (4) evaluate and demonstrate - in the lab and industry - the feasibility of the novel strategy via production of the world's first full-scale building component with this solution. Re3DSkin will enhance the resilience of newly built and existing assets by extending service life and address the UK's critical vulnerability of ageing assets. Developed solutions could reduce labour-intensive repair, maintenance and dependence on increasingly scarce skilled labour. Re3DSkin's findings can also reduce the use of carbon-intensive materials in SHCC and overall demand for repair materials during the whole-life of assets. Re3DSkin outcomes will contribute to a more productive, more sustainable and more internationally competitive construction sector.