HYBRID LIGHTWEIGHT STRUCTURAL SYSTEMS FOR LOW-COST HOUSING (HYLIGHTS)

如果不将建筑行业的碳足迹降至最低，就无法实现具有法律约束力的英国政府到2050年实现净零碳排放的目标。全球每年超过四分之一的钢铁产量用于建筑，但一项基于学校、办公室和住宅建筑的钢框架设计的研究显示，典型钢结构建筑的平均材料利用率低于其容量的50%。这项研究来自英国领先的设计咨询公司。这表明，通过设计最低材料，建筑中的钢材含量可以显著降低，这将每年在全球范围内避免2.14亿吨二氧化碳排放。为了减少建筑中的钢材消耗，开发新颖、材料高效和可持续的轻质结构是必不可少的。随着人口的增长，全球都需要住房，这与我们需要通过减少或提高建筑效率来减少排放产生了紧张关系。轻钢框架（LSF）结构由冷弯型钢（CFS）钉墙和梁式地板制成，在世界各地的现代建筑实践中越来越受欢迎，无论是在新开发项目中，还是在现有建筑的垂直扩展中，作为一种经济高效、低碳的解决方案。与传统方法相比，利用LSF结构进行非现场制造的便利性提供了许多好处，包括：(a)提高质量和生产率，减少材料使用，减少浪费，节省总施工时间和相关成本30-50%；(b)更灵活的设计解决方案，符合为制造和装配而设计的方法；(c)围绕自动化建设的技术的可扩展性。因此，LSF系统可以直接为满足英国政府雄心勃勃的房屋建设承诺做出贡献，并将建筑的初始成本和资产的整个生命周期成本以及二氧化碳排放量分别降低33%和50%。然而，由于薄壁CFS元件的低局部屈曲抗力、典型LSF系统的低横向刚度和鲁棒性以及当前设计和优化方法的局限性，LSF结构系统的当前使用受到限制。在LSF系统在英国和海外广泛使用之前，这些挑战应该得到解决。

The legally binding UK government target to reach net zero carbon emissions by 2050 cannot be achieved without minimizing the carbon footprint of the construction sector. Over one-quarter of the world`s annual steel production is used in the construction of buildings but a study based on steel-framed designs for schools, offices and residential buildings, sourced from leading UK design consultancies, reveals the average material utilisation ratio for typical steel buildings is below 50% of their capacity. This suggests steel content in buildings could be significantly reduced by designing for minimum material, which would annually avert 214 million tonnes of carbon dioxide emissions worldwide. To reduce steel consumption in construction, the development of novel, materially efficient and sustainable lightweight structures is essential. There's a global need for housing as populations grow which creates tension with our need to cause less emissions by building less or more efficiently.Light steel frame (LSF) structures made of cold-formed steel (CFS) stud-walls and joisted floors are gaining growing popularity in modern construction practice worldwide, both in new developments and as a cost-effective and low-carbon solution for vertical extensions to existing buildings. The ease of offsite manufacturing utilising LSF structures offers many benefits compared to traditional methods, including: (a) improved quality and productivity, reduced material use, less wastage and savings of 30-50% in total construction time and associated costs; (b) flexibility for more tailored design solutions complying with the Design for Manufacture and Assembly approach; and (c) scalability for the technologies around automated construction. LSF systems can, therefore, directly contribute towards meeting the UK Government's ambitious house building commitments and reducing the initial cost of construction and whole life cost of assets, and CO2 emissions by 33% and 50%, respectively. However, the current use of LSF structural systems is limited due to critical drawbacks such as low local buckling resistance of thin-walled CFS elements, low lateral stiffness and robustness of typical LSF systems and limitations of current design and optimisation approaches to exploit their full capacity. These challenges should be addressed before LSF systems can be widely used both in the UK and overseas.