Influence of hydrophobic treatments applications on the concrete carbonation delay

Water-repellents are increasingly used in the recent years. Those ones are generally used to reduce the degradation caused by freeze / thaw, by alkali-aggregates reaction or by chloride ions. The objective of this study is to determine if hydrophobic treatments also have an influence on the propagation of the carbonation front into the concrete. Capillary absorption tests, permeability to water-vapor and oxygen, FTIR, DSC and porosity were carried out on concrete samples. Six products with different concentrations, solvent and molecules were tested. The results showed that the application of a water-repellent delays the propagation of the carbonation front. The most efficient products were the silanes which presented a higher penetration depth. Concrete compactness and porosity played also an important role in silane penetration depth.