Experimental research on rheological properties of 3D printing hybrid-fiber reinforced engineered cementitious composites

Abstract By varying the sand-to-binder ratio ( s/b ) and testing time, the rheological properties of a novel 3D printing hybrid-fiber reinforced engineered cementitious composites (3DP-HECC) were experimentally investigated. The test results demonstrated that increasing s/b significantly enhanced the static yield stress, dynamic yield stress, and plastic viscosity of 3DP-HECC. To provide a more intuitive analysis of the impact of rheological properties on printing quality, the printing status of 3DP-HECC under different s/b was comparatively evaluated. The results demonstrated that the s/b -0.42 series exhibited uniform and defect-free filaments, whereas the s/b -0.52 and s/b -0.62 series displayed varying degrees of tearing or breakpoints in the printed filaments. Consequently, the optimal s/b for 3DP-HECC was determined to be 0.42.