Article of RILEM TC 292-MCC: life cycle assessment (LCA) of non-metallic reinforcement for reinforcing concrete: manufacturing, durability, dismantling, recycling and reuse: a review

The potential of non-metallic reinforcement to be an environmentally sustainable alternative to classic steel reinforcement in concrete has become evident in recent years. The high-performance fibres used to produce non-metallic reinforcement elements have a considerably lower weight to transferable tensile forces ratio and are almost non-corrosive under common exposures. These indicators allow for a high environmental performance throughout the extended life cycle of the product. At the same time, substantially more resources and energy per unit weight are required for their production in some cases, e.g. for carbon fibres, compared to conventional reinforcing steel. The presented work addresses this conflict by closing a number of obvious research gaps. Despite an increasing number of publications during the last years, so far there are no comprehensive sets of data available on the environmental impact of various concrete reinforcing materials. With the data compiled in this work, for the first time, an objective comparison of different reinforcement systems (conventional and alternative) is presented that differentiates various environmental impact categories and therefore enables to perform Life Cycle Assessment (LCA). Other often observed shortcomings in sustainability assessments in concrete constructions are that an extension of the service life due to improved durability and the burden a material poses at the end of its life cycle are not considered. Comprehensive reviews of durability considerations help to develop an estimation of the service life. In addition, a state-of-the-art on possible strategies for dismantling, recycling and reuse of alternative non-metallic reinforcement systems shows that the composition of the FRPs, i.e., fibre and matrix materials, not only has a strong influence on the environmental impact in the production phase, but also on the durability as well as on a possible reuse.