Steel in the Deconstruction Industry: From Recycling to Reuse

随着全球变暖继续对世界产生负面影响，要求脱碳的压力越来越大，特别是在排放水平较高的行业。钢铁生产产生的二氧化碳排放量占全球排放量的4%，其中一半来自建筑业。尽管钢铁回收利用减少了钢铁行业的排放，但还需要采取进一步措施，其中一项措施就是钢铁的再利用。通过钢的再利用，可以避免用于初生钢和再生钢的高温(高能和高碳)工艺，从而减少碳排放。目前发现的使用再利用结构钢的障碍是缺乏供应链整合、成本确定性和库存可用性。为了克服这些障碍，该项目将致力于建立未开发的钢材来源，使设计人员更容易获得重复使用的部件，并确定重新使用的部件的最合适最终用途。环境、经济和工程方面的考虑因素将通过跨学科的方法加以综合。由于影响上一段所述障碍和目标的因素如此之多，因此将以拆迁行业从钢材回收利用向钢材再利用过渡为重点。这将通过回顾当前的文献，从行业和案例研究的角度进行分析。该项目将比较过去40年拆迁行业的转变，从过度依赖运输到垃圾填埋，再到今天突出的材料分类和回收，并将这种转变推断为现代钢铁再利用。第二个目标是研究其他国家和组织目前遵循的做法，这些国家和组织增加了可重复使用的结构钢的采购、销售和使用。考虑到回收和再利用之间的差异，这一次要目标将特别重要，因为有许多种类的钢材可以回收，但再利用目前受到严重限制。钢结构有很多种：空腹梁、格构梁、组合柱、腹梁、多弦框架柱等。所有这些结构必须通过螺栓、螺丝、铆钉和焊接的组合连接在一起，在许多情况下还必须用金属涂层和/或油漆系统处理。在这些研究中，为了衡量不同因素的成功与否，我们会用一个可量度的指标来代表“成功”，例如政策改变对拆卸承建商造成的成本影响，作为鼓励的指标。然后将对该行业的任何成功变化进行分析，以了解该行业创建的项目的具体碳减排情况。尽管以这种方式衡量指标将是有限的。隔离不同的可能原因并将其与可衡量的结果联系起来的过程将特别重要，因为在任何现实世界的情况下，都有几个变化的因素存在于更广泛的背景下，所有这些因素都可能影响正在调查的任何指标。

As global warming continues to have a negative impact on the world there is a rising pressure for decarbonisation, especially in industries which contribute high levels of emissions. Steel production produces 4% of global CO2 emissions, with half of these emissions being attributed to the construction industry. Although the recycling of steel has led to a reduction in emissions from the steel industry further measures are needed, one such measure is the reuse of steel. Through the reuse of steel, the high temperature (high energy and high carbon) processes used for both virgin and recycled steel can be avoided, cutting carbon emissions.Currently identified barriers to using reused structural steel are a lack of supply chain integration, cost certainty and stock availability. In order to overcome such barriers this project will aim to establish untapped sources of steel, make reused components more accessible to designers and determine the most appropriate end-use for reused components. Environmental, economic and engineering considerations will be incorporated through a cross-discipline approach. As there are so many factors which impact both the barriers and goals mentioned in the previous paragraph, the demolition industries transition from steel recycling, to selling steel for reuse will be used as a focal point. This will be analysed through reviewing current literature, perspectives from industry and case studies. The project will compare the shift of the demolition industry over the past 40 years, from an overreliance on haulage to landfill, to the prominence of material sorting and recycling today, and extrapolate this transformation to modern steel reuse. A secondary goal is to study the current practices followed in other countries and organisations which have increased their acquisition, sale and use of reusable structural steel. This secondary goal will be especially important for factoring in the differences between recycling and reuse, there are many varieties of steel which can be recycled, but reuse is currently heavily limited. There are so many different structures which steel can be used to form: Vierendeel girders, lattice beams, compound columns, web beams, multi-chord frame-like columns etc. All these structures must be joined together by a combination of bolts, screws, rivets and welds and in many cases treated with metallic coatings and/or a paint system. All these factors have an impact on the feasibility of reuse which should be accounted for.To measure the success of different factors in these studies, a measurable metric will be used to represent "success", such as the cost implications incurred to a demolition contractor by a change in policy, as a metric of incentive. Any successful change to the industry will then be analysed to understand the reduction in the embodied carbon of projects it created. although there will be limits to measuring metrics in such a way. The process of isolating different possible causes and linking them to a measurable outcome will be particularly important, as in any real-world situation there are several changing factors which exist within a wider context, all of which could impact any metric under investigation.