Val av bjälklag : En jämförelse av massivt betongbjälklag, plattbärlag och samverkansbjälklag av trä och betong ur ekonomi och miljösynpunkt

Sammanfattning: Purpose: In 2016, the construction industry produced 21% of Sweden's total carbon dioxide emissions. To reduce these emissions, an alternative is to choose building components from an environmental perspective. At the same time, the client of the building wants to keep the costs of production down. An multi criteria analysis is a tool for weighing different aspects against each other. In this report environmental aspects and the economic aspects of three different slabs will be compared and analyzed to facilitate the choice of slabs. The slabs that have been analyzed are solid concrete slabs, filigree floor slabs and composite slabs of wood and concrete. Method: The report is based on a reference project of an office building with a span of 6 m and an area of 1000 m2 located in Jönköping. This information is used for calculating requirements and transport. To obtain the desired results, an Life Cycle Assessment and a cost analysis have been performed along with a document analysis as well as contact with suppliers of the slabs. The results from the Life Cycle Assessment and the cost analysis were then used to perform an multi criteria analysis where the various aspects were weighed together. Interviews were conducted to strengthen the weighing in multi criteria analysis and to find out how the choice of beams currently applies to the company PEAB. Findings: The results from the document analysis show that filigree floor slabs are the most advantageous when it comes to finances and that wood and concrete slabs are most advantageous from an environmental point of view. In the analysis of the empirical data collected from the interviews, it is shown that the financial aspect is more important and should be weighted higher than the environmental aspect in the multicriteria analysis. Multi criteria analysis shows that filigree floor is the most advantageous in both economy and environment. During the planning and in the choice of flooring, finances are one of the most important aspects, but also the working environment and the ease of installation. Implications: The conclusion of this report is that the filigree floor slabs are the most advantageous choice of floor slabs in terms of both economic and environmental aspects. This flooring is also shown to be the flooring that is often chosen for buildings similar to the work's reference project. This result is considered to be general for similar constructions as the reference project. Limitations: The work only considers the Life Cycle Assessment category Climate impact and greenhouse gases and considers only the period of cradle to gate (A1-A4). The costs that are calculated are for the purchase of flooring and materials, installation and transport