Static and dynamic mechanical characteristics of 3D-Printed anisotropic basalt fiber-reinforced cement mortar

Three-dimensional (3D) printed mortar, represents an innovative approach to construction, utilizing additive manufacturing techniques, distinct from traditional reinforced concrete (RC) formwork methods. In this study, chopped basalt fibers, each 6 mm in length, were added to the mortar at different volume ratios (2.5 ‰, 5 ‰, 7.5 ‰, and 10 ‰). The printable properties of basalt fiber-reinforced cement mortar (BFRCM), such as the extrudability, fluidity, setting time, and buildability, were evaluated to determine the optimal mix for 3D printing applications. The compressive and flexural strengths of 3D-printed anisotropic specimens with those of mold-cast specimens after 28 days of wet curing were compared. Additionally, the dynamic mechanical properties under various impact conditions were assessed using both the drop-weight impact test and the stress reversal split Hopkinson pressure bar (SRSHPB) test. The findings revealed that a fiber ratio of 7.5 vol‰ resulted in the highest compressive and flexural strengths. It is noteworthy that the anisotropic mechanical properties of the 3D-printed specimens exhibited a considerable enhancement in strength in the load direction perpendicular to the printing side. However, the results of the dynamic strength tests revealed that the interlayer adhesion at the printing interfaces of the 3D-printed specimens was weaker than that of the mold-cast specimens in both the drop-weight impact test and the SRSHPB test.