COMPARATIVE RESULTS OF CONCRETE COMPRESSIVE STRENGTH RISING BY ADDITION OF NANOSILICA AND MICROSILICA
Results of trials of different concrete’s additios are presented in paper: nanosilica (nanopowder and sol), obtaining from hydrothermal solutions, and microsilica. Charaterestics of additions were investigated: particles sizes, amorphous structure, impurities concentrations. Experiments on rising concrete’s (cement-send-water) compressive and bending strength by additions of nanosilica and microsilica were carried out. More high activity of nanosilica in form of sol comparatibly with microsilica was revealed. At the dose SiO2 0,01-0,1 mas.% relative cement addition in form of sol gave equal effect on concrete compressive strength rising as microsilica powder at the dose SiO2 5,0-10,0 mas.%. Thus, application of nanosilica sol is more effective than microsilica and optimal dose of nanosilica in 50 time less than microsilica under the same values of concrete compressive and bending strength rising. Application of nanosilica sol let used technological regulations of modified additions to concrete and building reinforced concrete in liquid form. In case of nanosilica sol application additional effects of risinf sulfate, freeze resistance and resistance to chlorides migration are possible.