Carbon emission analysis and evaluation of steel-concrete composite structure bridge based on fuzzy comprehensive evaluation comprehensive evaluation method.

Measuring the low carbon performance of buildings is a crucial method for achieving the construction industry's strategic goal of "double carbon." The carbon emission factor calculation approach proposed by the IPCC is utilized to create a carbon emission calculation model for a steel-concrete composite structure bridge across its whole life cycle. The discount rate is used to determine the dynamic carbon emissions of the steel-concrete composite structural bridge, which are then compared to the static carbon emissions. The carbon strength of the bridge is evaluated using a fuzzy comprehensive technique. The application analysis is conducted on the basis of a steel-concrete composite construction bridge in Beijing. According to the findings, carbon emissions are primarily concentrated during the preparation, production, and operation of building materials. The bridge's static and dynamic carbon emissions are 103.966 and 1378.674 ktCO₂e, respectively. After material recovery, the values are 95.141 ktCO₂e and 1107.751 ktCO₂e, respectively. The ratio of dynamic and static carbon emissions ranges from 7 to 34, highlighting the significance of temporal value. After recycling the components, the bridge's static carbon strength dropped from 2.565 to 2.353, while its dynamic carbon strength fell from 2.422 to 2.210, both of which were medium carbon strengths. The model proposed in this study can successfully examine the carbon emissions and strength of bridges from both environmental and economic perspectives, and it can be used to select more environmentally friendly building materials and construction methods to increase bridge efficiency. It also provides valuable data assistance for the establishment and execution of environmental protection measures, thereby promoting the industry's long-term sustainable development.