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，脱碳的压力越来越大，特别是在排放量高的行业。钢铁生产产生的二氧化碳排放量占全球的4%，其中一半来自建筑业。虽然钢铁的回收利用减少了钢铁工业的排放量，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。通过对钢材的再利用，可以避免用于原钢材和回收钢材的高温（高能量和高碳）工艺，从而减少碳排放。目前确定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铁资源，使设计师更容易获得再利用的部件，并确定再利用部件的最适当最终用途。环境、经济和工程方面的考虑将通过跨学科的方法纳入其中。由于有很多因素会影响上一段提到的障碍和目标，拆除行业从钢铁回收到出售钢铁再利用的过渡将被用作重点。这将通过审查当前的文献，行业和案例研究的观点进行分析。该项目将比较过去40年来拆除行业的转变，从过度依赖运输到垃圾填埋，到今天材料分类和回收的突出，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的现行做法，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。这一次要目标对于考虑回收和再利用之间的差异尤为重要，有许多种类的钢可以回收，但目前再利用受到严重限制。有这么多不同的结构，钢可以用来形成：空腹梁，格梁，复合柱，腹板梁，多弦框架式柱等所有这些结构必须连接在一起的组合螺栓，螺钉，铆钉和焊接，并在许多情况下处理与金属涂层和/或油漆系统。这些因素均会影响重用的可行性，而重用的可行性亦须加以考虑。在这些研究中，为衡量不同因素的成功程度，我们会采用一个可量度的指标来表示“成功”，例如政策改变对拆卸工程承建商所带来的成本影响，作为鼓励的指标。然后将分析该行业的任何成功变革，以了解其创建的项目的隐含碳减少情况。尽管以这种方式测量度量会有限制。分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，在更广泛的背景下存在着几个不断变化的因素，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.