Colloidal Silica - Ron Blank & Associates, Inc.

The Chemistry: Nano TechnologyThe particle size of the silica in colloidal silica is significantly smallerthan fumed silica particles at 5 nanometers. This creates a largerreactive surface which increases the volume of calcium silica hydrate,creating more CSH as it lowers the residual calcium hydroxide (acaustic crystalline byproduct) during and after cement hydration.CSH acts as a binder and imparts strength in concrete.When colloidal silica is added to concrete at the time of placement,compressive strength is increased. When added after hydration, theconcrete surface is “densified” as silica penetrates the surface tobond to the silica and calcium hydroxide to create CSH.