Researchers at the University of Sharjah have demonstrated that the structural performance of 3D-printed polymer reinforcement in concrete depends more on geometry than on the material itself, tells 3D Printing Industry. Led by Dr. Muhammad Talha Junaid, the team investigated whether fused deposition modeling (FDM)-printed polylactic acid (PLA) profiles could serve as an alternative to traditional steel reinforcement, particularly in environments where corrosion poses a major challenge.
Concrete performs well under compression but is weak in tension, making reinforcement essential. Steel has long been the preferred solution because of its strength and reliable bond with concrete. However, steel reinforcement remains vulnerable to corrosion, especially in coastal regions and infrastructure exposed to deicing salts. Corrosion products expand over time, causing internal cracking and costly repairs. While fiber-reinforced polymer bars offer a corrosion-resistant alternative, their relatively high cost has limited widespread adoption.
The Sharjah researchers focused on an alternative strategy: improving reinforcement performance through geometry. They fabricated 30 cement mortar beams containing FDM-printed PLA profiles and subjected them to three-point bending tests. The study compared round bars and flat plates with smooth, wavy, serrated, and triangular surface textures.
Results showed that surface geometry was the dominant factor affecting performance. Textured profiles increased load-carrying capacity by 40% to 120% compared with smooth designs. Flat plate reinforcements performed particularly well, carrying roughly twice the peak load of round bars and dissipating nearly five times more energy before failure. Their larger contact area and enhanced mechanical interlocking with the concrete matrix helped prevent pullout and improved structural behavior.
The best-performing PLA configuration achieved nearly 80% of steel’s bending strength while matching its ductility. Although long-term factors such as creep, fatigue resistance, and elevated-temperature performance remain untested, the findings suggest significant potential for geometry-optimized polymer reinforcement.
The study also aligns with broader research exploring structural applications for 3D-printed polymers. Rather than directly replacing steel in all situations, PLA reinforcement could offer a compelling solution where corrosion resistance, low weight, design flexibility, and on-demand manufacturing are priorities. The research highlights the growing role of geometry as a powerful engineering tool in construction materials and additive manufacturing.