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

最近的研究报告说，50%的修复混凝土在几年后再次失效(修复后5年内25%，10年内75%，15年内95%)，导致反复且昂贵的干预、材料消耗和运营碳足迹。强调零维护或最少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。自修复水泥复合材料(SHCC)是传统混凝土的一种有趣的替代方案。它们含有矿物或生物制剂，可以与渗入裂缝的水反应，产生化合物，密封开口，在发生重大损害之前治愈材料。由于与生产过程和裂纹位置相关的不确定性，文献中的主要方法使用在大量部件中均匀地部署自愈剂。尽管如此，研究已经确定了与在建筑部门实施自我修复材料有关的几个问题，其中包括材料成本的初始投资。Re3DSkin建议改变部件的部署策略和功能--使用现代建造方法--以便能够在表层选择性地沉积自愈剂，并根据部件表面每个部分的破裂可能性和程度定制不同的浓度。该表面层充当优化的再生蒙皮，以增强资源的性能。3DP技术可以提供所需的沉积控制和精度，以优化涂层的细观结构和厚度，便于通过在线添加外加剂进行不同的放置。Re3DSkin的广泛科学目标是：(1)使3DP工艺适用于具有可变自愈剂浓度的表层沉积，并具有更高的分布精度和精度；(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部件与具有均匀自愈剂的同等部件在整个体积中的自愈机制和材料效率，以及(4)通过生产世界上第一个使用该解决方案的全尺寸建筑部件，在实验室和工业中评估和演示该新策略的可行性。Re3DSkin将通过延长使用寿命来增强新建和现有资产的弹性，并解决英国资产老化的严重脆弱性。开发的解决方案可以减少劳动密集型维修、维护和对日益稀缺的熟练劳动力的依赖。Re3DSkin的发现还可以减少小肝癌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的成果将有助于建设一个更具生产力、更可持续和更具国际竞争力的建筑行业。

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.