CO2 balancing and optimization of bridge structures

Based on current knowledge, it is estimated that more than 50% of global CO₂ emissions are attributable to the construction sector, of which approximately one-third stems from infrastructure projects, with civil engineering structures such as bridges playing a particularly significant role in terms of the carbon footprint. Despite these high emissions, there is currently a lack of knowledge—as well as calculation methods—among both project owners and design firms or contractors regarding how much CO₂ is required for the construction and maintenance of bridge structures; therefore, reducing or optimizing the carbon footprint plays no role in planning and construction; contracts are typically awarded based on the lowest construction costs.

As part of this research project, the goal is to use comprehensive CO₂ life-cycle assessments for typical bridge structures in the state of Schleswig-Holstein

1. to provide an overview, transparency, and empirical data regarding CO₂ consumption over the life cycle of typical bridge structures; the values will be presented in tabular form to serve as the fundamentals for corresponding estimates of CO₂ requirements during preliminary planning and conceptual design phases.
2. Based on the CO₂ life cycle assessments, the key factors influencing CO₂ requirements will then be identified, and
3. specific measures are developed to reduce the CO₂ requirements of bridge structures in a manner that is as cost-neutral as possible

The measures include both the optimization of building materials and construction methods. With regard to abutment structures, for example, solutions using reinforced earth or gabion structures are currently being investigated.