Development of sustainable low carbon Engineered Cementitious Composites with waste polyethylene fiber, sisal fiber and carbonation curing

Engineered cementitious composites (ECC) is an advanced fiber-reinforced cementitious composite with high tensile ductility. However, the binder and fiber system in ECC incur high economic and environmental cost. In this study, a low carbon ECC was developed by substituting virgin polyethylene fiber with waste polyethylene fiber (WPE) from waste marine fishing nets. Carbonation curing was applied to further reduce embodied carbon footprint via direct CO2 mineralization. This research examined the low carbon ECC's mechanical properties, including compressive strength and tensile strength and ductility. The CO2 footprint and material costs of ECC were also investigated. The objective was to develop an ECC competitive to normal concrete economically and environmentally while maintain the unique ductile performance of ECC. Results suggest that carbonation-cured WPE reinforced ECC possesses 50% of the CO2 footprint and 37% of the cost of traditional concrete. Meanwhile, this low carbon ECC maintains at least 4 MPa tensile strength and 6% tensile ductility. This research demonstrates the feasibility of developing construction materials with low environmental impact while maintaining high performance for civil infrastructure applications. The adoption of WPE in ECC provides a plausible pathway to recycle marine waste into the construction industry that urgently needs to be decarbonized.