Characterization of morphology and texture of several amorphous nano-silica particles used in concrete

In the present research, the morphological and the textural characteristics of different amorphous nano-silica’s used in concrete were studied. To conduct a detailed characterization of the main properties of micro- and nano-silica, seven selected silica samples produced by different methods were studied thoroughly. The resulting characteristics, such as shape, particle size, specific surface area, density, and pore-size (distribution), are related and compared. Finally, the effects of the nano-silica characteristics on the slump-flow diameter and mechanical properties of standard mortars are discussed. It was found that the main parameters that influence the slump-flow diameter and the final mechanical properties of cement mortars are the specific surface area, the micropore volume and the average size of the primary particles of the silica’s. In addition, no direct influence on the mortar properties related with the silica’s pore diameter and pore-size (distribution) was found.