PSI - Issue 64

Urs Meier et al. / Procedia Structural Integrity 64 (2024) 29–39 Meier/Winistörfer / Structural Integrity Procedia 00 (2019) 000 – 000

38 10

The Verdasio project has provided excellent experience of the ease of installation of CFRP tendons and their excellent long-term behavior. Laminated loop tendons can also be bent around tight radii, e.g. in a bridge box girder. Based on this experience, a significant proportion of the 52% of steel tendons could potentially be replaced by CFRP tendons in the future. Winning the German Civil Engineering Award in 2022 and the German Bridge Award in 2023 for the Stuttgart light rail bridge could help promote CFRP tendons, especially as the laudatory speeches emphasized the innovation of CFRP hangers. The introduction of CFRP into the construction industry did not bring about a revolution. Instead, it has been and will continue to be an evolutionary process. It's worth noting that today young engineers in many places have been familiarized with modern fiber composite materials during their studies, which will further promote their use in the future. 4. Comments on the sustainability of CFRP in the rehabilitation of civil structures Per unit mass, CFRP scores poorly in terms of sustainability compared to steel. However, CFRP has a very high strength to weight ratio compared to steel. Table 3 shows the CO 2 emissions and energy consumption from cradle-to gate in the Life Cycle Assessment (LCA) of CFRP and steel. For externally bonded reinforcement (EBR), the main CFRP application in construction since 1991, 1 kg of CFRP typically replaces 27 kg of steel. As a result, CFRP causes 37% less CO 2 emissions than steel and requires 21% less energy for such a typical cradle-to-gate Life Cycle Assessment (LCA) application. Table 3. CO 2 emissions and energy input from cradle-to-gate in the Life Cycle Assessment (LCA) of CFRP and steel. Material Emission CO 2 [t CO 2 per t] Energy Input [GJ per t] Required mass for same task [t] Emission CO 2 [t CO 2 ) Energy Input [GJ] CFRP 47.47 675.90 1 47 (-37%) 676 (-21%) Steel 2.79 31.67 27 75 855

Fig. 9. Applied mass of CFRP. CFRP is highly resistant to corrosion, fatigue and other forms of environmental degradation. CFRP components require less maintenance and have a longer service life. This durability reduces the frequency of repairs and replacements, minimizing resource consumption and waste generation over time. The lightweight nature of CFRP reduces transport emissions and the energy required for installation. The use of CFRP to retrofit and strengthen existing structures extends their life without the need for extensive demolition and reconstruction. This not only conserves resources but also reduces the environmental impact associated with construction waste and the production of new materials. These are all additional benefits of CFRP While CFRP recycling is still somewhat of a challenge at present, progress is being made in recycling technologies. Techniques such as solvolysis are emerging that allow carbon fibers to be recovered and reused. Continued progress