Upcycling of recycled plastic fiber for sustainable cementitious composites: A critical review and new perspective

Recycling plastic waste into recycled plastic fiber (RPF) for use in sustainable cementitious composites is an effective method for reducing the amount of plastic waste generated. While, there are numerous studies available that focus on the properties of RPF and its reinforced cementitious composites, a comprehensive systematic review is rarely found. Therefore, this paper presents a critical review on the utilization of RPF in cementitious composites, with the aim of providing relevant researchers with an effective and comprehensive way for acquiring the necessary literatures. In this review, the current global situation regarding plastic waste and the recycling technology of RPF were firstly introduced, accompanied by a systematic comparison of the properties of various types of RPF. Subsequently, the micro properties, early-age properties, mechanical properties, durability and improvement methods of RPF reinforced mortar/concrete were reviewed in detail. Finally, the paper concludes with an outlook on the subject. The results showed significant variation in the properties and application condition among different types of RPF. The incorporation of RPF in mortar/concrete, particularly for enhancing tensile strength, demonstrated improvements due to its bridging effect with cementitious materials. Furthermore, the utilization of RPF in mortar/concrete exhibited excellent economic and environmental benefits.