US Patent 7410538 Granulated hydrophobic additive for cementitious materials

A cementitious material in powder form comprising cement, also comprises sufficient of a granulated hydrophobing additive, which comprises form 5 to 15 parts by weight of an organopolysiloxane component, form 10 to 50 parts by weight of a water-soluble or water-dispersible binder and from 50 to 90 parts by weight of a carrier particle, to give from 0.01 to 5% by weight of the organosiloxane component based on the weight of the cement. The cementitious material displays good hydrophobicity, which may improve upon subsequent wettings of the applied cementitious material to a substrate.