Life Cycle Sustainability Assessments of an Innovative FRP Composite Footbridge

Abstract

Sustainable construction and the design of low-carbon structures is a major concern for the UK construction industry. FRP composite materials are seen as a suitable alternative to traditional construction materials due to their high strength and light weight. Network Rail has developed a prototype for a new innovative footbridge made entirely from FRP with the aim of replacing the current steel design for footbridges. This study conducted a life cycle analysis of this novel composite footbridge design to quantify the cost and environmental benefits. An LCA and LCC analysis framework was used to analyse the environmental impacts and cost savings of the bridge throughout its lifespan from raw material extraction to its end of life. From the results of the LCA and LCC, the FRP footbridge sustainability was reviewed and compared to a standard steel footbridge. Due to the uncertainty of the fibre-reinforced plastic (FRP) structure’s lifespan, multiple scenarios for longevity at the assets-use stage were studied. The study revealed that the FRP bridge offered substantial economic savings whilst presenting potentially worse environmental impacts, mainly caused by the impact of the production of FRP materials. However, our study also demonstrated the influences of uncertainties related to the glass-fibre-reinforced plastic (GFRP) material design life and end-of-life disposal on the whole life cycle analyses. The results show that if the FRP footbridge surpasses its original estimation for lifespan, the economic savings can be increased and the environmental impacts can be reduced substantially.