Since antiquity the construction industry has been using lime based binders to manufacture mortars, plasters and renders...Despite this history there is still a lack of fundamental understanding of the hardening processes and how these influence time dependent mechanical properties. In addition dolomitic limes, containing magnesium, exhibit enhanced properties when compared to their pure lime counterparts, however there is limited knowledge of the underlying reasons. Lime based mortars are ideal candidates to replace cement mortars in many applications where lower strength is an advantage such as new build housing, forms of construction utilising organic fillers such as lime-hemp, and conservation and restoration applications. Indeed lime mortars offer many advantages over cement in terms of moisture permittivity, ability to accommodate movement, self-healing properties and ability to sequester carbon dioxide. Cementious binders are produced at much higher temperatures compared to lime and have large carbon dioxide emissions associated with their manufacture. Atomistic modelling provides a unique opportunity to probe these mechanisms at a fundamental level thereby elucidating the processes responsible for developing the properties of industrial importance. Many existing and past studies of building lime binders have focused on bulk properties for instance through large scale bulk property testing, whilst not taking into account atom level processes. In recent years the cement industry has employed atomistic modelling of hydrated silicates as a means of understanding material behaviour. Recent studies have demonstrated that the morphology and composition of a lime crystal can influence the carbonation process, and by association mechanical behaviour. In addition magnesium containing dolomitic limes show improved performance in many respects including strength development. Rate of carbonation is an extremely important issue as this can dictate the speed at which a building can be erected and therefore the associated costs. The ability to improve the carbonation rate and therefore hardening rate through control of composition and morphology will lead to enhanced products with better environmental credentials. In the first instance this proposal seeks to develop atomistic models to describe the important aspects of lime binder behaviour and validate these against laboratory samples. Atomistic models will generate Raman spectra and X-ray diffraction patterns for direct comparison with experimental measurements. These initial models will then be developed further to investigate firstly carbonation and then time dependent and plastic mechanical properties. Additionally the research will investigate the underlying reasons for the improved performance observed in magnesium containing dolomitic limes. The project is expected to bring long term benefits to the construction industry over the coming decades. In the shorter term industry will benefit through planned workshops and site visits which will showcase the application of atomistic modelling to lime manufacturers. The project will support the development of enhanced projects through the new knowledge gained.

This project seeks to advance the current understanding of carbonation in lime and cement materials. A novel approach is proposed where the reaction with carbon dioxide will be studied using micro pH electrodes. pH variations in a thin water film at the sample surface will allow the reaction mechanism to be determined. A detailed understanding of the surface morphology and composition will be provided by a comprehensive electron optical and surface analytical study. The reaction of these materials with carbon dioxide is or great interest as sequestration of carbon dioxide is a key initiative aimed at reducing climate change. Lime has the ability to adsorb significantly higher quantities of carbon dioxide during the setting process in comparison to alternative products such as cement and has important applications in the restoration and conservation of historic buildings in addition to renovation and new build projects. Cement acquires its strength from hydration of reactive silicate and aluminate clinker phases however in the long term carbonation of these phases can lead to a reduction in mechanical performance and the corrosion of steel reinforcements if present.Although the chemical process of carbonation is well known the mechanisms in lime and cement mortars are poorly understood. This research programme seeks to address this issue.In recent years the producers of low carbon footprint materials such as hemp and wastes from a range of industrial processes have expressed interest in the incorporation of their materials as fillers and additives in lime and cement products including mortars, renders, plasters and concrete. The addition of these environmentally friendly materials not only influence the micro and macro pore structure but soluble constituents may introduce ionic species into the pore water, the influence of which on carbonation is unknown. This proposal aims to study the carbonation process by monitoring ion concentrations at different locations within the liquid film on the surface of a calcium hydroxide substrate. Proton concentrations will be measured using specially manufactured microelectrodes consisting of nanostructured palladium hydride discs approximately 10 micrometers in diameter and electrodeposited on the end of a normal microdisc electrode. Held precisely with a micropositioner the pH microelectrode will be brought to within a few micrometres from the surface under investigation. In a similar way, commercially available ion selective electrodes will be used to determine the calcium ion concentration. In the second phase of the project the effect of ions leached from additives commonly used in conjunction with lime will be investigated. These can be divided into the following five groups, blast furnace slag (GGBS), bottle glass, wood ash, hemp and metakaolin.Additives of interest will include glass, ashes / slag and organic surfactants.

The increasing demand for low and zero carbon buildings in the UK has provided significant challenges for the energy intensive materials we currently rely on. At present somewhere between 20% and as much as 60% of the carbon footprint of new buildings is attributable to the materials used in construction; this is predicted to rise to over 95% by 2020. If the UK is to meet agreed 80% carbon reduction targets by 2050 it is clear that significant reductions in the embodied carbon of construction materials is required. What also seems clear is that current materials and systems are not capable of delivering these savings. The drive for an 80% reduction in carbon emissions, a decreasing reliance on non-renewal resources and for greater resource efficiency, requires step changes in attitude and approach as well as materials. Improvement in construction systems, capable of providing consistently enhanced levels of performance at a reasonable cost is required. Modern developments in construction materials include: eco-cements and concretes (low carbon binders); various bio-based materials including engineered timber, hemp-lime and insulation products; straw based products; high strength bio-composites; unfired clay products utilising organic stabilisers; environmentally responsive cladding materials; self healing materials; smart materials and proactive monitoring; hygrothermal and phase change materials; coatings for infection control; ultra thin thermally efficient coatings (using nano fillers); ultra high performance concretes; greater use of wastes; and, fibre reinforcement of soils. However, very few of these innovations make the break through to widespread mainstream use and even fewer offer the necessary step change in carbon reductions required A low carbon approach also requires novel solutions to address: whole life costing; end of life (disassembly and reuse); greater use of prefabrication; better life predictions and longer design life; lower waste; improved quality; planned renewal; and greater automation in the construction process. As well as performance, risk from uncertainty and potentially higher costs other important barriers to innovation include: lack of information/demo projects; changing site practices and opposition from commercial competitors offering potentially cheaper solutions.. A recent EPSRC Review has recognised the need for greater innovation in novel materials and novel uses of materials in the built environment. The vision for our network, LIMES.NET, is to create an international multi-disciplinary community of leading researchers, industrialists, policy makers and other stakeholders who share a common vision for the development and adoption of innovative low impact materials and solutions to deliver a more sustainable built environment in the 21st Century. The scope of LIMES.NET will include: adaptive and durable materials and solutions with significantly reduced embodied carbon and energy, based upon sustainable and appropriate use of resources; solutions for retrofitting applications to reduce performance carbon emissions of existing buildings and to minimise waste; climate change resilient and adaptive materials and technologies for retrofitting and new build applications to provide long term sustainable solutions. In recognition of their current adverse impacts and potential for future beneficial impacts, LIMES.NET will focus on bringing together experts to develop pathways to solutions using: renewable (timber and other plant based) construction materials; low-impact geo-based structural materials; cement and concrete based materials; innovative nano-materials and fibre reinforced composites. Through workshops and international visits the network will create a roadmap for multidisciplinary research and development pathways that will lead to high quality large research proposals, and an on-going virtual on-line centre of excellence.

This project seeks to advance the current understanding of carbonation in lime and cement materials. A novel approach is proposed where the reaction with carbon dioxide will be studied using micro pH electrodes. pH variations in a thin water film at the sample surface will allow the reaction mechanism to be determined. A detailed understanding of the surface morphology and composition will be provided by a comprehensive electron optical and surface analytical study. The reaction of these materials with carbon dioxide is or great interest as sequestration of carbon dioxide is a key initiative aimed at reducing climate change. Lime has the ability to adsorb significantly higher quantities of carbon dioxide during the setting process in comparison to alternative products such as cement and has important applications in the restoration and conservation of historic buildings in addition to renovation and new build projects. Cement acquires its strength from hydration of reactive silicate and aluminate clinker phases however in the long term carbonation of these phases can lead to a reduction in mechanical performance and the corrosion of steel reinforcements if present.Although the chemical process of carbonation is well known the mechanisms in lime and cement mortars are poorly understood. This research programme seeks to address this issue.In recent years the producers of low carbon footprint materials such as hemp and wastes from a range of industrial processes have expressed interest in the incorporation of their materials as fillers and additives in lime and cement products including mortars, renders, plasters and concrete. The addition of these environmentally friendly materials not only influence the micro and macro pore structure but soluble constituents may introduce ionic species into the pore water, the influence of which on carbonation is unknown. This proposal aims to study the carbonation process by monitoring ion concentrations at different locations within the liquid film on the surface of a calcium hydroxide substrate. Proton concentrations will be measured using specially manufactured microelectrodes consisting of nanostructured palladium hydride discs approximately 10 micrometers in diameter and electrodeposited on the end of a normal microdisc electrode. Held precisely with a micropositioner the pH microelectrode will be brought to within a few micrometres from the surface under investigation. In a similar way, commercially available ion selective electrodes will be used to determine the calcium ion concentration. In the second phase of the project the effect of ions leached from additives commonly used in conjunction with lime will be investigated. These can be divided into the following five groups, blast furnace slag (GGBS), bottle glass, wood ash, hemp and metakaolin.Additives of interest will include glass, ashes / slag and organic surfactants.

Our vision is to transform the lives of displaced people encamped in extreme conditions through an engineered solution to housing that promotes a new science of shelter design. The project will entail research in five of the world's largest refugee camps. Zaatari and Azraq (Jordan), Kilis (Turkey), Mae La (Thailand), Nyarugusu (Tanzania). These have populations of up to 250,000 and hence are in many ways cities. They have summer temperatures >35degC and occasionally >40degC; in these conditions un-insulated dwellings are unable to provide safe conditions. In addition, such locations can have 1600W/m2 of solar radiation, further raising the temperature inside a dwelling, and in the case of Jordan winter temperatures of -10degC. In Thailand the high humidity is likely to be of equal importance in placing thermal stress on occupants. In addition, displacement shelters can use polymeric materials which contain a high proportion of VOCs such as plasticisers and release agents, and have poorly ventilated cooking facilities using fuels such as wood, thereby generating particulates. Camps were once expected to be a short term solution, and this is still true in some settings. However, as witnessed in numerous locations around the globe, encampment often continues for years or decades (for example, the 340,000 strong Dadaab camp in Kenya opened in 1992). Even in natural disasters delays in rebuilding can lead to displacement camps taking on aspects of semi-permanent settlement. The challenges of survival in the immediate onset of an emergency quickly give way to concerns about the suitability of shelter over a longer timeframe. Such basic dwellings inhibit domestic life, educational delivery to the young, and development of the social relations needed for community cohesion. Often the need of traumatised people for a sense of security and privacy also goes unmet. Unfortunately, even the state of the art in current shelter provision does not adequately consider building physics, thermal comfort and air quality. There is also a general lack of attention to socio-cultural issues. Thus, for example, our pilot study in Jordan has revealed through social surveys a consistent concern amongst the displaced population with the issues of safety and privacy. Given the diversity of potentially available building materials, climates and cultures, there will be no single shelter solution, but rather a need for a systematic process of design that is cognisant of the climate, landscape, culture, length of time the accommodation might be needed, flexibility as family size changes and portability. This project will develop such a design process by creating a new science of shelter design through engagement with aid agency staff in four countries with diverse weather, cultural conditions and political sensitivities. This will involve 1) wide scale social and indoor environment surveys in five camps; 2) the construction of a series of potential designs in the UK, in a climate chamber and in Jordan; and 3) the production of a multi-language, extreme climate building physics-based, culturally sensitive, shelter design tool for agency field staff.