1. Roles of the reference service life (RSL) of buildings and the RSL of building components in the environmental impacts of buildingsTajda Potrč Obrecht, Roman Kunič, Sabina Jordan, Andraž Legat, 2019, objavljeni znanstveni prispevek na konferenci Povzetek: The Life Cycle Assessment of a building is a complex analysis that also involves the use of the predicted Reference Service Life (RSL) of the building components and materials, as well as the predicted RSL of the whole building. The RSL values of individual materials and building components can be obtained from different sources and are not exactly comparable. In the present study, the influence of selected RLS values on an LCA assessment was evaluated. Three different RSL databases were used as the sources of the data to estimate the environmental impacts of selected building components (internal wooden door and external finishing coat). Two scenarios were presented. In the first scenario a building component can be reused in another building, while in the second scenario the reuse of the building component is not possible. The study showed that dependent on the selected RSL database, the results can differ by up to a factor of five. Therefore, it is very important to describe clearly the maintenance scenarios for a building in order to have a reliable comparison of the results of LCA assessments.
Ključne besede: reference service life, life cycle assessment, refurbishment
Objavljeno v DiRROS: 08.03.2024; Ogledov: 124; Prenosov: 103
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2. An LCA methodolody for assessing the environmental impacts of building components before and after refurbishmentTajda Potrč Obrecht, Sabina Jordan, Andraž Legat, Marcella Ruschi Mendes Saade, Alexander Passer, 2021, izvirni znanstveni članek Povzetek: Refurbishment is one of the most important measures for reducing the environmental impacts of the construction sector in the near future. According to the life cycle assessment (LCA) methodology for buildings, the environmental impacts of refurbishment measures should be assessed within the whole life cycle of the building and reflected in separate modules. However, in practice, refurbishment is often treated as the beginning of a new building life cycle. This leads to difficulties in correctly assessing the environmental impacts for the components that are reused or recycled after the refurbishment. The division of a building’s life cycle into two separate life cycles indicates that the environmental impacts must be divided between the life cycle before and the life cycle after the refurbishment for a correct assessment of the environmental impacts and a calculation of the residual value. We propose a newly developed methodology for calculating the environmental impacts and the residual value of refurbishment measures that also involves a division between life cycles. The new methodology is a combi-nation of already exiting methodologies that are innovatively combined and consists of four sequential steps. In the first step, the input, output and reuse flows between the life cycles before and after the refurbishment are defined. In the second step, the environmental impacts are assessed using the chosen allocation approach (i.e., the cut-off, cut-off with module D, avoided-burden, 50:50 and the product environmental footprint (PEF)). In the third step, a maintenance scenario is implemented according to the selected reference-service-life (RSL) database. In the fourth step, the residual value is estimated. The methodology was tested on selected building components. A sensitivity analysis for different allocation approaches and RSL databases was performed to show how the choice of these parameters can influence the results. The differences between the selected allocation approaches emerge if materials with recycled content are used or if the materials are being recycled or reused at the end of their life cycle. The developed methodology reliably estimates the environmental impacts as well as the residual value of the life cycle before and after the refurbishment. We expect that this research will stimulate practitioners to avoid the negligence of previous environmental flows, bringing scientific consistency to future assessments of refurbishment measures.
Ključne besede: Life cycle assessment (LCA), refurbishment, allocation approaches, residual value, reference service life (RSL)
Objavljeno v DiRROS: 28.07.2023; Ogledov: 326; Prenosov: 210
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3. Impact of leaching on chloride ingress profiles in concreteAlisa Machner, Marie Helene Bjørndal, Aljoša Šajna, Nikola Mikanovic, Klaartje De Weerdt, 2022, izvirni znanstveni članek Povzetek: To investigate the effect of leaching on chloride ingress profiles in concrete and mortar, we exposed concrete and mortar specimens for 90 and 180 days to two different exposure solutions: 3% NaCl, and 3% NaCl with KOH added to limit leaching. The solutions were replaced weekly. After exposure, we determined total chloride profiles to investigate the chloride ingress, and portlandite profiles to assess the extent of leaching. The results showed that leaching during exposure greatly affects the chloride ingress profiles in mortar and concrete. We found that leaching leads to considerably higher maximum total chloride content and deeper chloride penetration into the concrete than in the specimens where leaching was limited. We recommend therefore that leaching should be taken into account in standard laboratory testing and that more mechanistic service life models should be used to take into account the impact of leaching.
Ključne besede: chloride ingress, service life prediction, leaching, concrete, portlandite, open access
Objavljeno v DiRROS: 04.05.2023; Ogledov: 280; Prenosov: 176
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