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

如果不最大限度地减少建筑业的碳足迹，英国政府到2050年实现净零碳排放的具有法律约束力的目标就无法实现。世界上超过四分之一的钢铁年产量用于建筑，但一项基于学校、办公室和住宅楼钢结构设计的研究显示，典型钢结构建筑的平均材料利用率低于其产能的50%。该研究来自英国领先的设计咨询公司。这表明，通过设计最低限度的材料，建筑中的钢材含量可以显著降低，这将每年避免全球2.14亿吨二氧化碳排放。为了减少建筑中的钢材消耗，开发新型的、材料高效的和可持续的轻质结构至关重要。随着人口的增长，全球对住房的需求越来越大，这与我们通过减少或提高建筑效率来减少排放的需求产生了紧张关系。由冷弯型钢(CFS)螺柱墙和连接楼板组成的轻钢框架(LSF)结构在世界各地的现代建筑实践中越来越受欢迎，无论是在新的开发项目中，还是作为现有建筑垂直延伸的低成本和低碳解决方案。与传统方法相比，使用LSF结构的异地制造具有许多优势，包括：(A)提高了质量和生产率，减少了材料使用，减少了浪费，总施工时间和相关成本节省了30%-50%；(B)符合制造和组装设计方法的更定制设计解决方案的灵活性；以及(C)自动化施工相关技术的可扩展性。因此，LSF系统可以直接为实现英国政府雄心勃勃的房屋建设承诺做出贡献，并将初始建设成本和资产的整个生命周期成本分别降低33%和50%。然而，由于薄壁CFS构件的局部抗屈曲能力较低、典型LSF结构体系的抗侧向刚度和稳健性较低，以及当前设计和优化方法的局限性，使得LSF结构体系的应用受到限制。在LSF系统能够在英国和海外广泛应用之前，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.