Steel-concrete composite beams using precast hollow-core slabs and a demountable shear connection mechanism

现代社会迫切需要可持续发展。随着自然资源变得越来越有限，环境污染在地球上许多地区已经达到令人震惊的程度，人为活动需要转向更可持续的思维和运作方式。世界各地的许多政府都为不久的将来制定了雄心勃勃的可持续发展目标。具体而言，英国政府已设定目标，到2050年将所有人为活动的二氧化碳（CO2）排放量减少80%。欧盟也将大幅减少二氧化碳排放、废物和能源消耗作为其议程的首要任务。建筑行业在实现可持续环境方面可以发挥重要作用，因为：a）新材料的生产是一个能源密集型过程，约占全球二氧化碳排放量的15%; B）建筑物通常在其使用寿命结束时被拆除，从而产生废物和污染，例如，在英国，拆除造成的废物占总废物的三分之一，而其中一半以上的废物仍被送往填埋场;以及c）根据最近的报告，到2050年，全球的材料需求将翻一番。此外，回收利用不是一个可持续的解决方案，因为回收过程仍然是非常能源密集型的，只需要比从头开始创造材料少一点点的能源。一个更可持续的解决方案是找到避免在建筑物使用寿命结束时拆除建筑物的方法。这可以通过开发创新的结构解决方案来实现，这些解决方案允许将建筑构件直接重新用于新项目。这样，施工将产生更少的CO2排放（因为不需要制造新的部件或回收旧的部件），更少的废物将进入垃圾填埋场，地球上的自然资源将得到更负责任的利用。钢-混凝土组合建筑有很大的市场份额（英国的多层办公楼和停车场超过70%），其中一半以上使用钢-混凝土组合楼板，即混凝土板与钢型材机械连接，从而实现更经济的设计。然而，目前建造复合地板的做法是在混凝土板和钢型材之间使用连接方法，这使得它们的分离非常困难;因此，这些建筑物的拆卸是非常成问题的。本项目提出了一种新颖的方法来连接预制混凝土板与型钢，其优点是：a）所有组件的非现场制造; B）施工现场简单快速的安装; c）组合地板的拆卸;和d）在新项目中直接再利用所有组件。该项目将采用实验测试，辅以数值分析，以开发拟议的新型结构系统。实验将进行两个板钢截面连接系统单独，以验证其结构性能，并在大型组合梁复制建筑物中的真实的梁。实验将提供有关拟议系统的物理行为和最终失效模式的证据，而使用先进数学模型的数值模拟将用于研究许多几何配置并概括测试结果。根据测试和模拟的结果，我们将为拟议系统的实际设计提出建议。该项目涉及与领先的学术界和主要工业合作伙伴的合作，以便为复合地板系统提供可靠的可持续解决方案。

There is an urgent need for sustainable development in modern societies. As natural resources become more limited, and environmental pollution has reached alarming levels in many regions on the planet, man made activities need to switch to a more sustainable way of thinking and operation. Many governments worldwide have set ambitious sustainability targets for the near future. The UK government, specifically, has set as target the 80% reduction in carbon dioxide (CO2) emissions from all anthropogenic activities by 2050. The European Union has also included the drastic reduction of CO2 emissions, waste and energy consumption as first priorities in their agenda.The construction sector can play an important role to achieving a sustainable environment, since: a) the production of new materials is an energy intensive process, which is responsible for about 15% of the global CO2 emissions; b) buildings are usually being demolished at the end of their useful life creating waste and pollution, e.g. demolition is responsible for one third of total waste in the UK, and more than half of this waste is still sent to landfill; and c) the material demands will be doubled globally by 2050 according to recent reports. In addition, recycling is not a sustainable solution, because the recycling process is still very energy intensive and requires only marginally less energy than creating materials from scratch.A more sustainable solution is to find ways to avoid demolition of buildings at the end of their useful life. This can be done by developing innovative structural solutions that allow for the reuse of building components directly to new projects. In this way, the construction will produce less CO2 emissions (as there will be no need to manufacture new members or to recycle the old ones), much less waste will go to landfill, and the natural resources of the planet will be used more responsibly.Steel-concrete composite buildings have a large market share (more than 70% in the UK for multi-storey offices and car parks) and more than half of them use steel-concrete composite floors, i.e. the concrete slab is mechanically connected to the steel sections, which results in more economic designs. The current practice of constructing a composite floor, however, uses a connection method between the concrete slab and the steel sections that makes their separation extremely difficult; thus, the disassembly of these buildings is highly problematic. This project proposes a novel way to connect precast concrete slabs with steel sections that offers the advantages of: a) off-site fabrication of all components; b) easy and fast installation on the construction site; c) disassembly of the composite floor; and d) direct reuse of all components in new projects.The project will use experimental testing complemented by numerical analyses in order to develop the proposed novel structural system. Experiments will be conducted on both the slab-steel section connection system alone, in order to characterise its structural behaviour, and on large-scale composite beams replicating real beams in buildings. The experiments will provide evidence on the physical behaviour and the ultimate failure modes of the proposed system, whereas numerical simulations using advanced mathematical models will be used to study numerous geometrical configurations and generalise the results of the tests. Based on the results of the tests and the simulations, recommendations for the practical design of the proposed system will be proposed.The project involves collaboration with leading academics and key industrial partners in order to deliver a reliable sustainable solution for composite floor systems.