Improving bond performance of 3D-printable earth-based mortar reinforced with jute fibers

3D printing technology has transformed the construction industry by enabling rapid and cost-effective production of complex geometries. However, it faces significant challenges, including sustainability concerns due to cement's environmental impact and reinforcement issues arising from the incompatibility of traditional steel. These challenges necessitate the development of innovative material solutions. This study aims to enhance the bond strength between sustainable earth-based mortar and jute fibers used as reinforcement in 3D printed structures by exploring the effects of different treatments and compositions. Bond strength was evaluated by considering the effect of different treatments on the resistance of the fiber to being pulled out of the mortar. Pull-out tests were conducted on specimens with varying compositions and treatments. Results demonstrated substantial improvement in bond performance; specifically, the reference sand-free earth-clay mortar exhibited the lowest interfacial shear strength of 0.30 MPa. The most remarkable enhancement was observed in specimen which jute fibers pre-treated by immersion in mud slurry, which showed a 147% increase, reaching an interfacial shear strength of 0.74 MPa. Combining sand addition and fiber pre-treatment, however, did not yield additional benefits. These results indicate that simple, cost-effective local treatments can notably enhance fiber-matrix bond strength in 3D-printed earth-based structures without necessitating additional equipment or significant expense.