The investigation of posibilities of concrete structure modification by silica fume to improve concrete properties was presented in this report. Percentage of silica fume in regard to cement varied between 0% and 20%. Concrete was cured as follows: in water, steam – curing regime at +60^oC and +90^oC. The results of the compressive and tensile strength, freeze / thaw resistance with de-icing salts, and depth of penetration of water under pressure.