The Comparative Life Cycle Assessment of Structural Retrofit Techniques

The current study conducts a comparative LCA of two alternative structural retrofit/ strengthening techniques - steel jacketing, and the carbon fiber reinforced polymer (CFRP) retrofit. A cradle-to-gate system boundary is used for both techniques. The results indicated that the CFRP retrofit technique has merits over the conventional steel jacketing in all three impact categories covered by this study. This is primarily attribute to the much less material consumption for CFRP retrofit as compared to steel jacketing for achieving the same load carrying capability of the retrofitted bridge structures. Even though the transoceanic transportation of carbon fiber has been taken into account in this study, the energy consumption and environmental impacts of CFRP transportation is still much smaller than steel due to it light weight property. The impacts of CFRP retrofit are mainly focused in the material manufacturing phase, which implies that the improvements in the carbon fiber manufacturing technology could potentially further reduce the environmental impacts of CFRP retrofit.