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Rebecca Hartwell

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3 records found

Mapping the flat glass value-chain

A material flow analysis and energy balance of UK production

Journal article - Rebecca Hartwell, Graham Coult, M. Overend

Glass is one of the UK’s eight energy-intensive industries. As such, it is under scrutiny to decouple growth in production from greenhouse gas (GHG) emissions. Recycled glass, also known as cullet, requires less energy to melt than primary raw materials in new glass production. The use of cullet thus reduces the energy intensity per unit of output whilst also reducing demand for primary material resources. However, efficient systems for flat glass collection are yet to be established in the UK, resulting in a limited supply of cullet available for the flat glass market and missed environmental opportunities. This study identifies the existing supply-chain inefficiencies in the UK glass industry in three stages. Firstly, the mass flows of materials within the three main glass sectors: container glass, flat glass and glass wool, are mapped from natural resource through to primary application and subsequent end-of-life management based on a reference year of annual production figures. The map is presented in the form of a “Sankey” diagram which draws attention to several opportunities for increasing resource efficiency; namely in the stark contrast in glass collection rates between the flat and container glass industry. Using the data collected on the annual mass flows of materials in the UK flat glass sub-sector, the energy (MJ) and GHG emission (CO2-eq) saving potential of enhanced end-of-life collection methods are assessed, based on three alternative recovery scenarios. These scenarios consider the use of alternative distributions of recovered flat glass cullet in the three primary glass sub-sectors. The emission savings resulting from each recovery scenario are evaluated, based on the estimated tonnage yield of finished flat glass products. It is shown that together with improved manufacturing yield, the reutilization of end-of-life flat glass as cullet in new production could reduce the annual emissions of the UK flat glass value-chain by up to 18.6%. Finally we review the existing barriers to recycling different glass types based on acceptability criteria and available take-back infrastructure, and thus find that the advancement of improved recycling rates will rely on establishing the business opportunity and/or supporting policy for developing efficient systems for flat glass collection.@en

End-of-Life Challenges in Façade Design

A disassembly framework for assessing the environmental reclamation potential of façade systems

Conference paper - M. Overend, Rebecca Hartwell

In recent decades, there has been increased attention to reduce the operational energy performance of buildings. Stringent legislation on building energy performance has stimulated facade design to evolve to serve numerous functions and meet complex technical requirements. This h ...

Effects of Humidity and the Presence of Moisture at the Bond-line on the Interfacial Separation of Laminated Glass for Flat Glass Re-use

Conference paper - Rebecca Hartwell, M. Overend

The built environment is under scrutiny to address environmental design challenges by considering a whole-life holistic approach that seeks reductions in operational emissions whilst simultaneously pursuing reductions in embodied emissions. Reduced embodied emissions can be found through the responsible sourcing of resources and re-use of materials in their highest obtainable value. Laminated glass is used widely within the building industry for improving security and for reducing the risk of human injury from glass fracture. At present, few options exist for the re-use and high-value re-cycling of laminated glass; it is most commonly disposed of in landfill or down-cycled into aggregate material due to its low perceived value at end-of-life. Whilst some efforts have been made to separate the poly-vinyl butyral (PVB) interlayer from glass in the automotive industry, such processes typically involve destructive crushing of the glass sheets and residual glass that is not at a high enough purity to be considered for re-cycling as cullet for visual glass applications. A more effective removal of the PVB-interlayer through severing of the PVB-glass interfacial bonds, would allow flat glass from existing laminated glass panels to be re-conditioned to fulfil the latest functional requirements in architectural glass. Whilst the temperature and strain rate dependency of the PVB-interlayer material itself has been well-researched, the fundamental nature of the interfacial bonding between glass and PVB, governed by initial processing, is not well-understood. This paper presents findings from the latest experimental research that explores methods of separating 2.9 mm x 100 mm x 150 mm flat glass sheets from a 0.38mm PVB-interlayer for flat glass re-use and/or re- cycling of glass sheets at their highest obtainable value at end-of-life. A bespoke standardised test has been developed by the authors inspired by the compressive shear test, to evaluate methods for achieving separation between the interlayer and glass on a small-scale. Tests were conducted at room temperature to evaluate the effects of varying displacement rate (0.125mm/min, 0.5mm/min and 1.0mm/min), humidity exposure and the influence of water infiltration along the bond line. It was found that the influence of humidity-ageing and water infiltration along the glass-interlayer interface during separation led to a greater proportion of delaminated area compared to the un-aged samples. The greater proportion of delaminated area was found to be a result of a mixture of the effects of a change in the bulk material properties of the interlayer and the intrinsic value of interfacial adhesion.@en

Contributed

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Reclaim and reuse potential of load-bearing components of se school buildings

Research into the criteria to define the reclaim and reuse potential of load-bearing components of SE school buildings in the Netherlands at an early stage

Master thesis - N.M.A. Bouwens, H.M. Jonkers, A.C.B. Schuurman, Rebecca Hartwell, M. Overend, Johanna Scherer

Global awareness has arisen for sustainable development to reduce the burden of the building sector on the earth’s ecosystems. One of these sustainable developments is the transition towards a 100% circular building economy with high-quality reuse. However, the sector has insufficient knowledge and understanding about the possibilities and opportunities to transition towards a circular economy. In the current linear economy outdated existing buildings are demolished and replaces with new buildings. This research provides knowledge on a new design strategy of giving existing load-bearing components a proper end-of-service life application by reusing them. This research focuses on outdated school buildings in the Netherlands and sees these existing school buildings as urban mines to extract load-bearing components for new school buildings. In this way, the linear building cycle of load-bearing components closes, and the switch to a circular building economy is possible. This research proposes a quantitative assessment of the potential reclaim and reuse of existing load-bearing components. Determining the degree of reclamation and reusability starts with assessing individual components on several indicators. A literature study, interviews, and surveys with practitioners determine the indicators and sub-indicators that influence reclamation and reusability. Each indicator and sub-indictor influence the reclaim and reuse of load-bearing components from the indoor environment. Moreover, the reuse of existing components takes place in new SE school buildings, and therefore, the component must meet the current technical requirements. Subsequently, this research collects the required information for each reusability indicator, the theoretical knowledge. Afterwards, the reusability indicators are translated into an assessment method. The assessment method can quantitatively measure the reclaim and reuse potential technically by giving each indicator and sub-indicator a score for reclaim and reuse. Each reusability indicator has a score ranging from 0 = ‘not reusable’ to 1.0 = ‘highly reusable’. The reusability indicators are independent and weigh equal. As a product, this research translated the theoretical knowledge and assessment method into a practically usable, rapid supportive assessment tool. In this way, awareness, knowledge and insight can be provided about the reuse of load-bearing components. The assessment of the reclaim and reuse potential can serve as a supportive tool that helps school organisations and the project teams with the initial decision to apply the reuse of load-bearing components in the construction process of a new SE school building. This decision making