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“It’s been a solution looking for a problem,” says Terry Wohlers, president of Wohlers Associates, a consulting firm focused on additive manufacturing, referring to 3-D printing’s use in construction. Printing with concrete is difficult and can’t compete with the efficiency of building components that are mass-produced in factories, he notes.
Certifying the safety of new materials will also take time. Integrating structural reinforcements like rebar with 3-D printing adds other complexities.
Proponents say new approaches will address such challenges and printing big structures promises benefits including slashing the amount of material used.
“Almost all structures now have much more material than we need” due to standardized designs and materials’ constraints, says Areti Markopoulou, academic director at the Institute for Advanced Architecture of Catalonia in Barcelona. Ms. Markopoulou helped lead a team that spent almost two years developing a footbridge made from concrete reinforced with glass fibers that they printed in sections off-site and assembled on installation in a park outside Madrid.
Printing also permits real-time feedback on how a bridge handles stresses, thanks to embedded sensors that let engineers monitor forces on and within the structure. Applying those forces to a digital twin of the physical bridge permits modeling of unlimited scenarios for use in predictive maintenance of printed bridges. And by seeing precisely how a bridge twists and flexes, engineers can reinforce or trim subsequent designs with unprecedented precision.
IAAC and Autodesk are now working on bridges and housing printed from recycled and sustainable materials.