SUMMARYUnderstanding structural behaviour of buildings during a fire is accepted as being essential to make full use of the recently introduced performance-based design codes. However, currently the behaviour of buildings during the cooling phase of a fire is poorly understood. Evidence from full-scale tests and real fires has shown that collapse of buildings can occur during the cooling stage of the fire, which can compromise the safety of firefighters and the public in the proximity of the building. This joint project between Manchester and Edinburgh University, will investigate the behaviour of cooling steel-concrete composite structures to gain an understanding of their behaviour and the underlying mechanics. The project includes testing of composite slabs, subject to different axial restraint conditions and natural fire scenarios, to obtain a unique understanding of forces generated within the structure during the cooling stage of a fire. Working in parallel to the experimental phase of the project, existing numerical models will be extended to simulate structural behaviour during the cooling phase. Once validated, the numerical models will allow an understanding of the behaviour of complete structures during the full duration of the fire, significantly advancing the current modelling capabilities which concentrate on the behaviour up to the fire's estimated maximum temperature. The results from the complex models, together with the experimental results, will allow simple design rules to be developed to ensure that buildings do not collapse during the cooling stage of the fire, thus ensuring the required level of safety for both firefighters and the public.

Steelmaking generates a range of combustible gases, generally of a low calorific value. Historically the cost of capturing, conditioning and storing these gases significantly exceeded the cost of natural gas. Process equipment developments over time have replaced gas by-product use with natural gas supply.Lowering the Carbon Footprint of steel production and rising energy prices demands a thorough review of energy use on site. Currently the site operates gas fired boilers mainly fired by process gas, generating high pressure steam for electricity generation and feeding a low pressure steam ring main for use across the steelworks. Additional package steam boilers supplement low pressure steam on site.Over decades the steel plant has developed with many changes introduced. Steam use is ubiquitous but it may not be the best option. The purpose of this research is to map current steam use on site and to determine other sources of low grade heat. The current monitoring and control of steam generation and use will be considered and improved control methodology proposed for any chosen system.Corus has commenced investment in excess of 60m to capture, condition and store more process gas, this research is key to determining how best this gas can be utilised on site.Combustible gases produced on site will be researched to determine optimum combustion characteristics, whether conventional combustion or gas turbine. Methods of generating electricity and or steam using low grade heat or process gases will be examined to determine whether these new methods would be preferable and use less energy than the current steam ring main. Alternative thermal cycles, for example Kalina, will be researched to utilise low grade heat for electricty generation and steam or heat raising.If beneficial uses cannot be found for the low grade heat on site, other uses for example district heating will be investigated.

We rely on metallic objects every day, from bicycles and bridges to the solder joints in our electronics. In each case, a key step in manufacturing is the solidification of liquid alloy, and it is through controlling solidification that we can control grain structure and defects. Solidification is at the heart of current challenges facing the UK: steel and aluminium production contributes more than 10% to global industrial CO2 emissions, and new solder technologies are required to enable the manufacturing of smaller, more powerful portable electronics. In all these industries, advances will involve controlling the solidification microstructure and controlling solidification defects. Key to the development of grain structure in solder joints and structural castings are the earliest stages of solidification when the number-density of grains is determined by the number density of nucleation events. The project will use new microscopy techniques which combine focussing an ion beam to micro-machine into the centre of crystals and find nucleant particles with electron diffraction to understand how the particles catalyse nucleation. With this information, new ways to control nucleation will be explored. After nucleation, the semi-solid grain structure goes on to significantly affect the formation of defects in castings and solder joints. Part of tackling this challenge is to develop a deeper understanding of how and why casting defects form. It is known that the origin of semi-solid cracking is the stresses and strains that develop during solidification but, to understand the details, we need to observe and measure how numerous solidifying crystals respond to loads during solidification. Metals and alloys are opaque to visible light and their inner structure is therefore hidden from our eyes. By pouring liquid alloy, we can see that they have a low viscosity and that the viscosity increases considerably as alloys solidify, but we cannot see or measure what structural changes are causing these changing flow properties. X-rays can be transmitted through metals, offering the potential to observe the development of microstructure, but it is only in the last decade that X ray sources have become available with sufficient flux and coherence to allow real-time imaging of crystal growth in alloys. This was an enormous step forward as it became possible to test solidification theories developed in 'post-mortem' studies using real metallic samples. This project will extend these synchrotron techniques to observe and measure the solidification of intermetallic grains in solder joints, and to study how deformation of the semi-solid grain structure leads to casting defect formation. We aim to observe and measure for the first time where intermetallics nucleate in solder joints and how they grow during solder reactions. This will give us insights that we can use to engineer solder joint microstructures and tackle the final frontiers in the transition to Pb-free soldering such as a replacement for high-Pb solder for use at T>180C. Similar techniques will be applied to imaging the formation of inter-columnar cracking in experiments analogous to the continuous casting of steel, a process used to produce more than one billion tonnes of steel annually. An exciting aspect of this part of the research is that much about semi-solid alloy deformation is unknown: How is force transmitted from crystal to crystal? What happens when two crystals are pushed into one another? Do they bend? Do they fragment? Do they behave as rigid bodies? Why do strain instabilities develop? Where do cracks begin and how fast do they grow? These questions can only be fully answered with in-situ observations of deformation at the scale of the microstructure. We have begun to address these questions in pilot studies and now we aim to expand this to crack movement in the mush.

Understanding structural behaviour of buildings during a fire is accepted as being essential to make full use of the recently introduced performance-based design codes. However, currently the behaviour of buildings during the cooling phase of a fire is poorly understood. Evidence from full-scale tests and real fires has shown that collapse of buildings can occur during the cooling stage of the fire, which can compromise the safety of firefighters and the public in the proximity of the building. This joint project between Manchester and Edinburgh University, will investigate the behaviour of cooling steel-concrete composite structures to gain an understanding of their behaviour and the underlying mechanics. The project includes testing of composite slabs, subject to different axial restraint conditions and natural fire scenarios, to obtain a unique understanding of forces generated within the structure during the cooling stage of a fire. Working in parallel to the experimental phase of the project, existing numerical models will be extended to simulate structural behaviour during the cooling phase. Once validated, the numerical models will allow an understanding of the behaviour of complete structures during the full duration of the fire, significantly advancing the current modelling capabilities which concentrate on the behaviour up to the fire's estimated maximum temperature. The results from the complex models, together with the experimental results, will allow simple design rules to be developed to ensure that buildings do not collapse during the cooling stage of the fire, thus ensuring the required level of safety for both firefighters and the public.

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