Reduction of water absorption in silicate treated concrete by post-treatment with cationic surfactants

As part of a study to assess the efficacy of impregnations for masonry substrates, the treatment of concrete with soluble silicate solutions and further treatment with various curing agents have been compared. Tests were performed on small specimens in the laboratory. Impregnation of permeable concrete with soluble silicate solution followed by impregnation with a dilute solution of particular alkyl quaternary ammonium salts reduced the rate of water absorption significantly. The water vapour permeability of the substrate was not significantly affected.