No abstract

Brückenbauwerke werden für eine sehr lange Lebensdauer geplant und errichtet. Vor allem für Straßenbrücken ist bei der Beurteilung eine Abkehr von den reinen Herstellungskosten in Richtung einer lebenszyklusorientierten, ganzheitlichen Bewertung voranzutreiben. Durch die Bottom-Up-Analysen an Realbauwerken, die typische Autobahnbrücken mittlerer Spannweite repräsentieren, wurden detaillierte Untersuchungen durchgeführt. Die Resultate von Lebenszykluskostenrechnungen, Ökobilanzierung und Berechnungen von externen Effekten werden hier für drei Varianten von Autobahnbrücken dargestellt und analysiert. Analyses of steel-composite bridges according to sustainability-holistic assessment of motorway crossings with quantitative methods. Bridges are designed and built for a long life-cycle. For motorway bridges concerning the assessment in view of sustainability no longer construction costs should be decisive. By using a bottom-up approach representative bridges are analyzed representing typical solutions of medium span highway bridges. Results of life-cycle cost analyses, life-cycle environmental analyses and calculations of external effects are shown and analyzed for three variants of motorway crossings.

Life cycle assessment (LCA) is the standard method for the quantification of environmental impacts within the construction sector, relying on available generic LCA databases. New developments, such as the increased influence of the building construction for LCA and the forthcoming of building information modeling (BIM), implicate new requirements on multiscale levels of development and complexity for LCA construction databases. At the example of the German “Ökobau.dat”, one of the leading LCA construction databases, this publication discusses whether the database is able to meet these requirements. The analysis shows the strengths of the Ökobau.dat with regard to standardization conformity (EN 15804, ILCD), data provision in machine-readable XML format, and the provision of an application programming interface. Shortcomings include incorrect linking of building life cycle inventory data with environmental information, incorrect documentation of functional units, missing generic datasets, the modeling of energy use data or the lack of a uniform structuring, or material classification. The authors propose solutions such as the provision of appropriate functional units, the implementation of a top-down approach to investigate the completeness of data based on existing nomenclatures or the extension with an appropriate material classification. This would allow for future viability and adaptability of Ökobau.dat for digital LCA.

Introduction: The application of the Life Cycle Assessment (LCA) technique to a building requires the collection and organization of a large amount of data over its life cycle. The systematic decomposition method can be used to classify building components, elements and materials, overcome specific difficulties that are encountered when attempting to complete the life cycle inventory and increase the reliability and transparency of results. In this paper, which was developed in the context of the research project IEA EBC Annex 72, we demonstrate the implications of taking such approach and describe the results of a comparison among different national standards/guidelines that are used to conduct LCA for building decomposition. Methods: We initially identified the main characteristics of the standards/guidelines used by Annex participant countries. The “be2226” reference office building was used as a reference to apply the different national standards/guidelines related to building decomposition. It served as a basis of comparison, allowing us to identify the implications of using different systems/standards in the LCA practice, in terms of how these differences affect the LCI structures, LCA databases and the methods used to communicate results. We also analyzed the implications of integrating these standards/guidelines into Building Information Modelling (BIM) to support LCA. Results: Twelve national classification systems/standards/guidelines for the building decomposition were compared. Differences were identified among the levels of decomposition and grouping principles, as well as the consequences of these differences that were related to the LCI organization. In addition, differences were observed among the LCA databases and the structures of the results. Conclusions: The findings of this study summarize and provide an overview of the most relevant aspects of using a standardized building decomposition structure to conduct LCA. Recommendations are formulated on the basis of these findings.