Enhancement of concrete durability by introducing SiO2 nanoparticles

We used SiO 2 nanoparticles, introducing them as stable aqueous sols from hydrothermal solutions, to enhance the mechanical properties of concrete. SiO 2 nanoparticles 10–100 nm in size with a specific surface of 60–500 m 2 /g were brought in the cement-sand-water system ranging from 0.01 to 0.3 wt % (with respect to the amount of cement). The nanoparticles were homogeneously distributed, applying a Relamix superplastificator ranging from 0.8 to 1.0 wt % (with respect to the amount of cement). The concrete was prepared by accelerated high-temperature hardening. The compression and bending durability were measured as the functions of the weight fraction of nanoparticles; the compression durability of solid samples was found to significantly depend on this parameter. We also studied the influence of the water/cement ratio on the properties of concrete.