This study investigates the mechanical and impact resistance properties of high-performance cementitious composites (HPCCs) incorporating hybrid fibers under a low water-to-binder ratio, with a focus on the multi-scale synergistic effects of different fiber types. Aramid fibers (AFs), basalt fibers (BFs), and calcium sulfate whiskers (CSWs) contribute to reinforcement at the macro, meso, and micro levels, respectively. Experimental results reveal that hybrid fiber systems significantly outperform single-fiber composites in terms of both impact resistance and crack suppression. The optimal mix design—comprising 3% CSW, 0.067% AF, and 0.033% BF—achieved a remarkable 233.3% increase in impact energy absorption compared to the control group. This enhancement is attributed to the complementary roles of the three fibers: CSWs refine the pore structure and mitigate microcrack propagation; AFs effectively restrain the development of macrocracks due to their high tensile strength and aspect ratio; and BFs contribute to energy dissipation through crack bridging and mechanical interlocking. Statistical analysis using the two-parameter Weibull distribution accurately characterized the variability and reliability of the impact resistance data, while pore structure analysis confirmed a reduction in average pore diameter and a more favorable pore size distribution. These findings underscore the effectiveness of fiber hybridization in improving the mechanical behavior and dynamic load resistance of cement-based composites, offering valuable insights for their application in demanding engineering scenarios.

Based on mortar composites with a low water–cement ratio, the effects of hybrid aramid fiber (AF), calcium sulfate whisker (CSW), and basalt fiber (BF) on their mechanical properties and wear resistance were studied, and the correlation between wear resistance and compressive strength are discussed. A microstructure analysis was conducted through scanning electron microscopy (SEM) and the nitrogen-adsorption method (BET). The research results show that compared with the control group, the compressive strength, flexural strength, and wear resistance of the hybrid AF, CSW, and BF mortar composites with a low water–cement ratio increased by up to 33.6%, 32%, and 40.8%, respectively; there is a certain linear trend between wear resistance and compressive strength, but the discreteness is large. The microstructure analysis shows that CSW, AF, and BF mainly dissipate energy through bonding, friction, mechanical interlocking with the mortar matrix, and their own pull out and fracture, thereby enhancing and toughening the mortar. A single doping of CSW and co-doping of CSW and AF can refine the pore structure of the mortar, making the mortar structure more compact.