Abstract: To study the effects of SiO₂ and PVA fibers on the static and dynamic mechanical properties of cement-based materials, the compressive strength, flexural, and impact resistance tests of Nano-SiO₂ mortar, PVA fiber mortar, and Nano-SiO₂-PVA fiber mortar were carried out. The impact number and impact energy of Nano-SiO₂-PVA fiber mortar were analyzed based on a two-parameter Weibull distribution. The results showed that the volume content of PVA fiber is 1.0 vol. % and the Nano-SiO₂ is 1.8%, the compressive strength and flexural strength of Nano-SiO₂-PVA fiber mortar are increased by 8.4% and 32%, respectively. Compared with ordinary mortar, the energy consumption of initial cracking and damage impact of Nano-SiO₂-PVA fiber mortar is increased by 833.3% and 1 160.0%, respectively. Although the addition of PVA fibers reduce the compressive strength of mortar, it significantly increases the energy consumption of initial cracking and damage impact.Nano-SiO₂ and PVA fiber exert a synergistic effect that improve the compactness of the matrix. Due to the bridging effect of PVA fiber and the filling effect of Nano-SiO₂, the matrix pores formed by PVA fibers are filled by the hydration products, refining pore morphology and delaying crack propagation. Furthermore, the impact times and impact energy consumption prediction models of Nano-SiO₂-PVA fiber mortar with different failure probabilities are established.

Key words: Nano-SiO₂, PVA fiber, impact resistance, Weibull distribution