Modification of Silica Gel by Nanosilica

Abstract

Consolidants based on silica gel have been widely used for the consolidation of decaying monuments. Consolidants reinforce building materials by replacing cement that has decayed. However, silica gels are formed by polycondensation, during which process they shrink and may crack from the internal tension. Therefore, their lifetime is limited and the building materials have to be treated time and time again. In this study, we investigate whether silica nanoparticles are able to absorb the internal stress caused by gel solidification and, thereby, prevent crack propagation. We carried out a time domain study of the sol-gel process under a stable laboratory conditions.