Testing concrete-encased steel from the 1950s for direct reuse

钢是最有用的建筑材料之一。它坚固、耐用、高效，自19世纪中期以来，它一直在我们的建筑环境中发挥着重要作用。它也很容易回收——事实上，废物流中的大部分废钢已经被捕获并适当地回收成新钢。但这只是故事的一半。制造新钢铁需要有限的材料，包括煤。制造新钢和回收钢需要1500摄氏度以上的熔炉温度，这意味着大量的能源消耗。即使能源可以来自可再生能源，化学过程本身也会释放二氧化碳，这是一种温室气体。目前的炼钢方法是不可能脱碳的。这意味着我们将无法在净零经济中使用目前的方法生产钢铁。钢通常用于现有建筑。当这些建筑被拆除时，钢铁被废弃、熔化并回收成新的钢铁制品。虽然这听起来很积极，但这是一个非常耗能的过程。有些制造方法不能容纳大量废钢。在英国，我们产生的废料超过了我们的处理能力，其中75%最终被出口。我们需要关闭材料循环，避免再制造，因为现有的钢材可以完美地重复使用。重复使用的钢材的碳足迹比传统钢材小8倍。1970年以后生产的钢材受标准制造工艺和尺寸的约束，因此很容易验证重用。钢结构研究所有一个标准的方法来检查这些部分的再利用。但现代炼钢始于1855年，所以这就遗漏了相当一部分现有的钢铁。该项目旨在通过严格的材料测试和质量分析，验证伦敦四座解构建筑中的大量20世纪50年代钢材库存，并提出再利用潜力，以保持钢材的最高价值。该项目具有创新性，因为它将知识和理解的范围扩展到当前协议未涵盖的材料库存，并可能促进现有钢结构的更大比例的再利用，有助于进一步闭合材料循环。

Steel is one of the most useful construction materials. It is strong, durable and efficient, it has been instrumental in our built environment since the mid-1800s. It is also easy to recycle -- in fact, most of the scrap steel in waste streams is already captured and properly recycled into new steel.But this is only one half of the story. Making new steel requires finite materials including coal. Making new and recycled steel requires furnace temperatures above 1500 degrees C, which means intense energy use. Even if the energy could be sourced from renewables, the chemical process itself releases carbon dioxide, a greenhouse gas. Current methods of steel manufacture are impossible to decarbonise.This means we will not be able to manufacture steel using current methods in a net zero economy.Steel is commonly found in existing buildings. When those buildings are demolished, the steel scrapped, melted and recycled into new steelwork. While it sounds positive, it is very energy-intensive process. Some manufacturing methods cannot accommodate high volumes of scrap steel. In the UK, we generate more scrap than we can deal with, and 75% of it ends up being exported.We need to close the materials loop and avoid remanufacturing when existing steel can be in perfect shape to be simply reused. Reused steel has a carbon footprint eight times smaller than traditional steel.Steel made after 1970 was subject to standard manufacturing processes and sizes, so it is easy to validate for reuse. The Steel Construction Institute has a standard method to follow for those sections to be checked for reuse. But modern steelmaking started in 1855, so this leaves out a significant proportion of existing steel.This project aims to validate a large stock of 1950s steel from four deconstructed buildings in London, by undertaking rigorous materials testing and quality analysis, and coming up with a reuse potential to keep the steel at its highest value.The project is innovative because it extends the scope of knowledge and understanding to a stock of materials that is not covered by current protocols and might facilitate the road to reuse for a larger proportion of existing steelwork, helping to further close the materials loop.