Performance of Cement Systems with Nano- SiO_2 Particles Produced Using Sol-gel Method

摘要

The reported research examines the effect of 5-70 nm SiO_2 nanoparticles on the mechanical properties of nanocement materials. The strength development of portland cement with nano-SiO_2 and superplasticizing admixture is investigated. Experimental results demonstrate an increase in the compressive strength of mortars with SiO_2 nanoparticles. The distribution of nano-SiO_2 particles within the cement paste plays an essential role and governs the overall performance of these products. Therefore, the addition of a superplasticizer is proposed to facilitate the distribution of nano-SiO_2 particles. The application of effective superplasticizer and high-speed dispergation are found to be very effective dispersion techniques that improve the strength of su-perplasticized portland cement mortars, reaching up to 63.9 MPa and 95.9 MPa after aging during 1 and 28 days, respectively. These values compare favorably with the observed compressive strengths of reference portland cement mortars of 53.3 MPa and 86.1 MPa. It is concluded that the effective dispersion of nanoparticles is essential to obtain the composite materials with improved performance.