Hardened Properties of 3D Printable Ultra-High Performance Fiber-Reinforced Concrete for Digital Construction Applications

The current progress of 3D concrete printing technique is hampered by the limited range of printable concretes and reinforcing methods. To tackle both limitations, a 3D printable ultra-high performance fiber-reinforced concrete (UHPFRC) was developed in this study with using locally available materials for digital construction applications. The hardened properties of the developed 3D printable UHPFRC, including density, compressive strength and flexural strength were experimentally measured. The effect of testing directions on the compressive and flexural strengths of the 3D printed UHPFRC was also investigated. A conventionally mold-cast UHPFRC counterpart mix was also made for comparison purposes. The results showed that the compressive strength of the printed UHPFRC samples exhibited an anisotropic behavior, depending on the loading direction. However, the flexural strength of the printed UHPFRC samples was comparable in lateral and perpendicular directions. The results also showed that the density and compressive strength of the printed UHPFRC specimens were relatively lower than those of the mold-cast samples. However, the flexural strength of the printed UHPFRC specimens was higher than that of the mold-cast specimens.