Abstract

This research group has developed a hydrophobic release agent using hydrophobic silica nanoparticles containing hydrophilic functional groups, which form hydrogen bonds with the water present in the fresh concrete and hydrophobic groups (CH3) that are distributed on the surface of the concrete providing hydrophobic properties to the surface. A vegetable oil was used as a support for the development of the release agent, using different types of nanoparticles and modifying the molar ratio between the precursors Methyltriethoxysilane (MTES) and Tetraethylethylsilicate (TEOS). Each release agent was used for the impregnation of standardized molds in the manufacture of concrete specimens. The hydrophobic properties of the test specimens were studied by measuring the contact angle of the water respect to the .It was observed that the best release agent was manufactured by using a nanosilica having a molar ratio of 2.5, which presents a contact angle higher than 145 º.