Enhancement of concrete durability by introducing SiO2 nanoparticles

We used SiO2 nanoparticles, introducing them as stable aqueous sols from hydrothermal solutions, to enhance the mechanical properties of concrete. SiO2 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.