Using waste jute bags as reinforcement to enhance geopolymers: An eco-friendly solution for sustainable construction

This study investigates the enhancement of geopolymer performance through reinforcement with natural jute fibers. The effect of fiber content on compressive and flexural strengths was evaluated by incorporating varying percentages of jute fibers into a phosphate washing sludge (PWS) based geopolymer matrix to form composite materials. Mechanical properties, including compressive and flexural strengths, were characterized, and the microstructure was analyzed using scanning electron microscopy (SEM). The results showed that the control sample (without fiber) achieved a compressive strength of 50 MPa. Adding 0.5 wt% and 1 wt% fibers reduced compressive strength by 21% and 32%, respectively, while the addition of 0.75 wt% fiber resulted in a 17% reduction, maintaining a compressive strength of 40.8 MPa. In contrast, flexural strength increased with the addition of fibers. At 0.5 wt%, it rose by 2%, reaching 9.6 MPa, and at 0.75 wt%, it peaked at 12.3 MPa, representing a 30% improvement. However, further fiber addition (1 wt%) led to a significant decrease in flexural strength to 6.2 MPa. SEM analysis revealed a toughened matrix with fiber-induced crack deflection, enhancing both toughness and ductility. These findings suggest that jute fibers can improve flexural properties without significantly compromising compressive strength, presenting a promising eco-friendly solution for sustainable construction materials. • Recycled jute bag fibers were incorporated into PWS-based geopolymer composites. • Untreated fibers enhanced flexural strength through crack-bridging mechanisms. • Compressive strength decreased with increasing fiber content. • Optimal mechanical balance was achieved at 0.75 wt% fiber content. • The approach supports waste valorization in non-structural construction materials.