A Bibliometric and Systematic Review of the Use of Recycled Composite Materials with an Emphasis on the Mechanical Performance of Structures

The paper provides a bibliometric and systematic review of the utilization of recycled composite materials, focusing on their mechanical performance in structural applications. Analyzing 1525 publications from the Web of Science database using VOSviewer, the study identifies trends, key topics, and collaboration networks. Findings show that recycled fiber-reinforced polymers (FRPs) maintain up to 93% of their virgin tensile strength under optimal pyrolysis conditions, while mechanical recycling can reduce tensile properties by up to 29%. Advances in hybrid composites and recycling technologies have facilitated sustainable applications in the construction, transportation, and energy sectors. China is a dominant contributor to research on recycled composites, with the USA making strong contributions as well. Other countries, including England, India, and Germany, have active research communities, while nations such as Saudi Arabia, the Republic of Korea, and Spain demonstrate growing global participation in this field. The bibliometric analysis highlights a significant increase in global research activity, with key trends focusing on additive manufacturing, circular economy practices, and sustainability. Despite these advancements, challenges persist, including high operational costs and variability in recycled material quality. This review underscores the need for standardized protocols and improved lifecycle assessments to accelerate the adoption of recycled composites in engineering practices.