Sustainability of utilizing recycled plastic fiber in green concrete: A systematic review

This paper addresses the escalating environmental issue of plastic waste (PW), which poses significant disposal challenges and contributes to ecological degradation. In contrast, recycling and reusing plastic waste offer substantial environmental and economic benefits, far outweighing traditional landfill methods. The paper reviews various economic models and treatment strategies for waste disposal of PW. It also critically analyses the effect of RPF on fresh properties of concrete, mechanical behavior, ductility, acoustic performance, and thermal properties. Studies show that adding recycled plastic fibers (RPF) decreases concrete workability, with higher fiber contents causing greater reductions, though workability remains acceptable within certain dosage limits. This study shows that incorporating waste plastic fibers (WPFs) or PET fibers improves concrete's compressive strength up to 0.75%–1.5% and flexural strength up to 0.6%–1.75%, but higher fiber contents lead to strength reduction due to weak bonding and poor dispersion. This study also shows that recycled fibers like PET, PP, and HDPE improve concrete durability, with PET offering high alkaline resistance, PP prone to pull-out, and HDPE providing friction-based adhesion. The integration of PW into the construction industry, both as aggregate and fiber, has the potential to enhance sustainability from both environmental and economic perspectives. This paper provides insights and a global perspective that may guide new pathways toward sustainability for researchers and professionals in the construction sector while also offering recommendations for future academic inquiries.