Transforming waste fishing gear into sustainable reinforcement fibers for cementitious composites: A comprehensive study on optimization, durability, and life cycle analysis

With the rising environmental concerns over marine plastic pollution, particularly from discarded fishing gear, this study explores the potential of utilizing waste fishing trawl (WFT, polyethylene) and waste fishing rope (WFR, polypropylene) fibers as sustainable alternatives to commercial polypropylene (CPP) fibers in cementitious composites (CC). The WFT and WFR were cleaned using a natural six-month process validated by salinity monitoring and then mechanically cut into fibers of different lengths. The physical and mechanical characteristics of these fibers were assessed, as well as their resistance to wear and tears in an alkaline environment. The optimal formulation was identified as ∼20 mm fibers at 0.7 % volume, which increased flexural strength by 41.6 % while causing only a moderate reduction in compressive strength (−8.4 % compared to control). Durability assessments showed that PE fibers enhanced freeze–thaw resistance and retained higher strength after fire exposure (up to 300 °C) relative to CPP. Life cycle analysis revealed environmental benefits, including a 9 % reduction in CO₂ emissions and 38 % lower fossil resource use. These findings highlight the feasibility of valorizing marine plastic waste in sustainable construction materials. • PE and PP fibers from discarded fishing gear reinforce cementitious composites. • Optimal fiber length (about 20 mm) and 0.7 % volume fraction improve strength and workability. • PE fibers increase flexural strength by 41 % and demonstrate enhanced durability. • PE fibers enhance freeze-thaw durability and maintain strength following fire exposure. • Life cycle study indicates a reduction of up to 38 % in fossil fuel use and a 40 % decrease in ozone impact.