MIT turns recycled plastic into structural trusses that beat US housing load tests

Engineers at MIT have developed a method to convert recycled plastic waste into high-strength structural floor trusses using large-scale 3D printing. These trusses, made from recycled PET polymer pellets reinforced with glass fibers, demonstrated exceptional durability by supporting 4,000 pounds—double the load requirements set by U.S. federal housing standards. The lightweight trusses, weighing only 13 pounds each compared to heavier timber counterparts, were produced rapidly, with each truss printed in under 13 minutes. The design incorporates a traditional ladder and triangle wood truss pattern enhanced with reinforced joints for added stability, ensuring rigidity and load-bearing capacity comparable to conventional materials. The MIT team, led by researcher AJ Perez, aims to address the global housing crisis sustainably by replacing wood and concrete—both environmentally problematic materials—with recycled plastic. They highlight the environmental impact of traditional construction, noting that meeting future housing demands with wood alone would require deforestation on an unprecedented scale. Currently, the prototypes use high-quality factory plastic waste,