Rodrيguez، نويسنده , , Erich D. and Soriano، نويسنده , , Lourdes and Payل، نويسنده , , Jordi and Borrachero، نويسنده , , Marيa Victoria and Monzَ، نويسنده , , José M.، نويسنده ,
Five silica fumes from different manufacturers were subjected to ultrasonic treatment in order to decrease particle agglomeration and improve particle dispersion. The effectiveness of the sonication was observed as a reduction in particle size distribution of sonicated silica fume (SSF) compared to non-sonicated silica fume. SSF was added to Portland cement, and then the hydrated paste was analysed by thermogravimetric analyses (TGA/DTG) and scanning electron microscopy (SEM/EDX). The results were compared with those of control pastes made with untreated densified silica fume (DSF), as well as a reference cement paste of ordinary Portland cement (OPC). A maximum grade of de-agglomeration by the sonication was obtained, with a high volume of particles of diameter less than 1 μm. Images obtained by transmission electron microscopy (TEM) of the SSF showed sintered particles that could not be fragmented by the treatment. Micro-structural characterisation results showed an increase in the reactivity of the silica fume after the treatment.
thermal analysis , silica fume , Particle size distribution , dispersion