Circular economy applications in railway infrastructure: A comprehensive evidence-based review
Juan Tan, Mehdi Koohmishi, Guoqing Jing, Sakdirat Kaewunruen, Yunlong Guo
Abstract
Circular economy (CE) has emerged as a widely-recognized and vital paradigm across multiple sectors of the construction industry. Considering the complexity of ballasted and ballastless railway tracks, CE has remarkable potential to be employed throughout their whole lifecycle towards sustainability. This review paper examines the implementation of CE based on 10R principles—refute, rethink, reduce, reuse, repair, refurbish, remanufacture, repurpose, recycle, and recover—on all components of substructure and superstructure of ballasted and ballastless railway tracks, covering the potential applications from design and construction to maintenance and end-of-life stages. In this context, promotion of CE in railway infrastructure can be achieved not only by enhancing the use of recycled materials and byproducts during the construction and maintenance stages, but also by leveraging digital information technologies. Tools such as material passport, 3D printing, and virtual reality, will further facilitate the implementation of CE principles from the earlier stages of the design lifecycle. Moreover, the state-of-the-art inspection technologies based on the remote sensing and Internet of things (IoT) can be employed to extend the lifespan of track components and apply optimized preventive maintenance activities based on as-needed repairs. In this context, digital platforms like geographical information system (GIS), building information model (BIM), and digital twin, enable the employment of these advanced technologies for promotion of CE based on 10R principles. The characterized strategies will pave the route to Net Zero by 2050 by involvement in the reduction of material quantities from design and construction efficiencies towards changing inspection and maintenance activities, highlighting reduction of CO 2 intensity