Concrete is one of the most widely used materials in the world. For many years traditional processes have been used to make concrete parts. However, over the last decade, 3D printing has revolutionised the way concrete parts are made. Complex concrete parts can now be created with no formwork or mould tooling. This is important as it removes the time and expense associated with making the moulds, but critically it also offers the potential to create parts that are structurally optimised to maintain strength with less material. This brings benefits in terms of cost but also it represents a significant environmental benefit as less material is needed, so carbon dioxide equivalent emissions are also reduced. The process is still in development though, and current 3D printing processes result in geometric forms and surface finishes that are not always desirable, and part accuracy that is too low for many applications. To address this, the 3D printing process can be followed immediately by a subtractive process that mills the surface to trim off unwanted material. This improves both accuracy and surface finish. By using a two-stage process of deposition followed by milling, it is possible to create high-quality parts, with intricate features and well-controlled surface finishes. The problem is that for each new part manufactured in this way, many iterative process development trials are required to perfect the deposition and milling strategy. This is time-consuming and wasteful, and it is a barrier to the uptake of the technology. The First Time Concrete (FT-Concrete) project will address this problem by creating new digital process and material models that can be used to help design printing and milling strategies without the need for physical trials. To do this, these models will be coupled within a digital workflow that enables optimised process design of both the material deposition and the milling process together. So, for a given part the feasibility of defect free manufacturing can be assessed, and the part or process design can be optimised, to ensure parts are printed right first time. This will be a two-way process, where printing sequence, speed and geometry will be optimised to suit milling requirements and vice versa. To achieve this the FT-Concrete project will investigate new time-dependent material properties models that can predict the curing state and optimal milling window and milling parameters for every position in a part. These must account for the variability of the mix, ambient conditions, printing sequence and the shape of the printed parts. New complementary process models for milling 3D printed concrete in a 'green' state will also be created. These must be able to cope with the highly variable material properties inherent to curing concrete. Finally, these new models will be integrated within a digital design system that will reduce, or potentially remove, the need for physical prototype parts. The new digital process and material models that we envisage, together with a digitally coupled design process will have significant commercial value; as they have the potentially to reduce process development time, material waste, and cost. We believe this could unlock 3D concrete printing to a wide range of new applications, boosting the uptake of the technology. Enabling structures and geometries that are currently impossible to produce. To pave the way for the uptake of these models, our aim is to integrate them within freely available, opensource, 3D printing design software. In addition, we will work with industrial partners to demonstrate the potential of the digital approach through industrially driven case studies.

The Government's Industrial Strategy highlights the need for the construction industry to embrace digitally-driven, automated manufacturing if it is going to deliver the planned infrastructure development, building and renovation of the built environment. The group funded through this award understands this need and envisages an industry that routinely deploys digitally-driven, off-site-manufacturing technologies to deliver customised and unique precision components to enable the rapid, just-in-time assembly of the built environment. Seamless digital workflow and accurate process simulation will reduce the time from design to product from weeks to hours, delivering buildings faster. It will facilitate the optimisation of components, removing unwanted material (reduced resource use and embedded CO2), designing out interfaces and reducing assembly time and complexity, both during installation and at end of life. 3D Concrete Printing (3DCP) is a digitally-driven, off-site manufacturing technology that is establishing itself worldwide as a viable manufacturing process, but its potential beyond aesthetic objects is fundamentally limited by the manufacturing tolerances achievable. The work undertaken by this group will develop the next generation, Hybrid Concrete Printing (or HCP), technology that uses 3DCP to create a near-net-shape (an object slightly larger than the desired object) and then uses subtractive process (cutting, milling and drilling) to remove a small amount of material to create the net-shape - the desired object to sub-millimetre precision. HCP technology will enable the intelligent integration of building performance and energy production and storage technologies, freed from traditional constraints on form and finish. This will unlock the potential for accurate interfaces and assemblies and, hence, open the gateway for a revolution in design and manufacture of buildings and the wider built environment. The team will develop research that answers three central goals of the Industrial Strategy Challenge Fund's Transforming Construction initiative: - Designing and managing buildings: We will develop and promote new design tools and design capabilities for UK design practise that will create globally marketable expertise; - Constructing quality buildings: HCP, a digitally-driven off-site manufacturing technology, will realise greater precision in manufacture than is currently possible, enabling repeatable, high quality components to be manufactured with a much shorter lead-time; and, - Powering buildings: The technology gives the designer close control of surface finish and component geometry, enabling them to add value through function and to design in order to integrate other active components as part of automated assembly.

This fellowship will develop a new generation of analysis and decision making tools required for engineers to respond to the challenges of intensifying global change. Consumption of energy and other resources is widely acknowledged to be unsustainable at today's rates. The world is therefore faced with the challenge of designing and implementing the transition to a more sustainable situation, a state in which greenhouse gas emissions and resource consumption (e.g. energy, water, materials) are drastically reduced and our society is well adapted to the impacts of climate change. Infrastructure systems such as water, energy, transportation and waste are the array of physical assets (and associated processes) responsible for moving the goods and services that ensure the safety, health and wealth of cities and their inhabitants. Thus, design and management of infrastructure has implications in terms of vulnerability and resource consumption (e.g. denser cities use less energy per capita on private transport, but can aggravate flooding and heat stress). However, effective management of infrastructure systems is challenging because they (a) vary in space, (b) are highly interconnected, (c) interact strongly with an ever-changing environment and population, and, (d) deteriorate with age. Nowhere is this more evident than cities, where over half the global population live and more than three quarters of global resources are consumed. As cities adapt in response to global pressures such as climate change, it is crucial to understand the implications of these adaptations in terms of resource requirements to avoid confounding parallel sustainability initiatives. Whilst the vulnerability of the built environment to climate impacts is to some extent understood, resource flows, such as energy, waste and water within cities are currently poorly-understood and are generally considered in terms of gross inputs and outputs to the urban area. The relationship between urban form, function and these resource flows has only been established from observational evidence e.g. relating population density directly to total transport energy demand. This provides insufficient evidence to appraise, plan and design specific adaptations as it does not account for crucial properties of the urban system such as land use, human activity, or the topology and attributes of the infrastructure systems that mediate this, and other, relationships (for example, land use and flood risk). To plan and design adaptations in urban areas requires a capacity to analyse the behaviour of whole cities over timescales of decades, to simulate and test the effectiveness of alternative management options and to monitor and modify the system performance. The capacity to adequately understand and model processes of change within the coupled technological, human and natural systems that comprise cities does not yet exist. This fellowship will address this priority area, through the development of a novel coupled systems simulation model of urban dynamics, climate impacts and resource flows within cities. This systems integrated assessment model will be used to analyse the relationship between the spatial configuration of cities and their infrastructure systems, resource consumption and vulnerability to climate change impacts. Working closely with key stakeholders in industry and local government I shall develop, demonstrate and apply decision analysis methods to show how long term planning strategies can be developed for re-engineering cities from their 'traditional' form into more sustainable configurations.In doing this, I shall provide the evidence to underpin more sustainable engineering and policy decisions and reduce the harmful impacts of unmitigated global change in urban areas.

Poor air quality is widely recognised to affect human health and wellbeing. Cumulative exposure to pollutants throughout the life course is a determinant for numerous long term health conditions including dementia, heart disease and diabetes, Short term high exposures are shown to exacerbate conditions such as asthma and COPD, increase risks of heart attacks and stroke and influence respiratory infections. The very young, very old and those with pre-existing conditions are most at risk and inequality further increases this; the poorest in society often live in the lowest quality housing in the most polluted areas. Human exposure to air pollutants occurs in both indoor and outdoor environments. Urban air pollution results from a combination of local outdoor sources (e.g. transport, combustion, industry) and regional and large scale atmospheric transport of pollutants. We spend up to 90% of our time indoors and indoor air quality is therefore a significant part of human exposure. Indoor air quality is influenced by the climate, weather and air quality in the external environment in addition to local indoor sources (e.g. microorganisms, chemicals cleaning and personal care, cooking, industry processes, emissions from building materials, heating and mechanical systems) and the building design and operation. In all cases it is the airflows within and between indoor and outdoor locations that enables the transport of pollutants and ultimately determines human exposures. Understanding airflows is therefore at the heart developing effective mitigating actions, particularly in cases where there is limited ability to remove a pollutant source. Being able to predict the influence of airflows enables understanding of how pollutants are likely to move within and between buildings in a city, both under normal day-to-day conditions and in response to emergencies such as heatwaves or wildfires. With the right computational and measurement tools it is then possible to change the design or management of city neighbourhoods enabling better urban flows to reduce exposure to pollutants and also to innovate new ventilation solutions to control the indoor environment in buildings. While there are a number of approaches that already enable assessment of urban flows and indoor flows, these aspects are not currently considered together in an integrated way or focused on optimising environments for health. The Future Urban Ventilation Network (FUVN) aims to address this by defining a new holistic methodology - the Breathing City. This will define a new integrated assessment approach that considers coupled indoor-outdoor flows together to minimise exposure for people within a neighbourhood who are most at risk from the effects of poor air quality. The network will bring together people from a range of disciplines and areas of application with a common interest in improving urban and indoor airflows to improve health. Through small scale research and workshop activities we will advance the understanding of the fluid dynamics that determines the physics of this indoor-outdoor exchange. The network will develop a research programme to address technical gaps in modelling and measuring pollutant transport and how we can use this to determine long and short term exposures to a range of pollutants. We will work collaboratively with industry, policy makers and the public to understand how this approach could change city planning, building design guidance and community actions to enable health based future urban ventilation design and to "design out" health risks for people who are most vulnerable.

Schools are planning to re-open in September and with the recent increased awareness of airborne transmission of Covid-19, there is an urgent need to monitor the situation and to provide guidance on ventilation best practice. This is emphasised by the expected onset of cooler weather when there will be a conflict between maintaining high fresh air ventilation flows and energy consumption and occupant comfort. We will quantify the risk of airborne COVID-19 transmission in schools and evaluate the effectiveness of mitigation measures, by developing techniques to assess the absolute risk of infection in a given indoor space, using field studies in primary and secondary schools, complemented by laboratory experiments and CFD to elucidate the flow patterns responsible for airborne transport. The understanding generated will underpin recent developments in infection modelling to predict the likelihood of airborne transmission within schools. The project will reduce the uncertainties associated with airborne transmission routes and provide evidence to evaluate mitigation measures. The scenarios we will investigate include changes to ventilation, use of screens, classroom lay-out and occupancy profiles. The methodology will facilitate application to offices, restaurants, shops etc. Airborne infection occurs through re-breathed air, the concentration of which can be directly inferred from measurements of CO2. Indoor flow is strongly affected by the locations of windows or vents, the heat rising from occupants/equipment and disturbances caused by people movement. Thus, accurate representations of these processes in the laboratory and CFD are needed to interpret the monitoring data currently collected in schools, which are typically single point measurements.