Beslutsunderlag vid val av klimatsmarta brokonstruktioner

Sammanfattning

Introduction (and aim) – The construction and civil engineering sector accounts for a significant portion of Sweden's greenhouse gas emissions, where material selection and early decisions in the design phase have a major impact on the climate. Bridges are resource-intensive structures with a long lifespan, which makes the choice of design and materials crucial for the total climate impact over the life cycle. Previous research shows that climate impact is often prioritized lower than cost and technical requirements. The aim of the study is to investigate the extent to which carbon dioxide equivalents are included in decision-making when choosing bridge structures and what factors affect this integration. Method – The study was conducted as a survey of the industry with a qualitative approach based on semi-structured interviews and document study. The interviews were conducted with designers, constructors and clients in bridge design. The document study included assignment descriptions from the Swedish Transport Administration and technical documents from consultants, PM (Memoranda) construction works. The material was analyzed with thematic analysis to identify recurring patterns and factors linked to how carbon dioxide equivalents are handled in the procurement process and the design phase. Results – The results show that carbon dioxide equivalents are included to some extent in decision-making, but that they are rarely decisive when choosing a bridge design. Decisions are largely based on cost, technical requirements and service life. Climate calculations are mainly carried out in larger projects and often in later stages, while early decisions are largely based on experience and standard values. In practice, climate data is therefore mainly used as a support for accounting rather than as a basis for decision-making. Analysis – The analysis shows that the integration of carbon dioxide equivalents is affected by several interacting factors, including regulations, procurement forms, technical limitations and material properties. The competence, experience and working methods of the actors involved are also of great importance. In addition, the use of climate data is limited by a lack of standardized methods and uncertainties linked to data quality and life cycle assessment. Discussion – The results show a clear gap between theoretical knowledge about climate impact and its practical application in bridge projects. Although methods for quantifying climate impact are available, these are often used to a limited extent or at too late a stage to influence key decisions. This indicates that current working methods do not fully enable climate impact to have an impact on decision-making. The study shows that increased integration of climate data in early stages is crucial to enabling more climate-smart choices. Furthermore, clearer requirements, standardized working methods and increased expertise within the industry are required to strengthen the climate perspective in decision-making processes. This is central to reducing emissions in the construction sector and enabling more sustainable bridge structures.