Author(s)

J. Grobe & Chr. Zeine

Abstract

For the preservation and restoration of historic monuments, both hydrophobization of natural sandstones and consolidation (strengthening) of damaged structures are of comparable importance. In practice a separation of these applicational measures would be highly desirable, but unfortunately they often are interdependent. Thus, the conventional hydrophobic treatment of sandstones with alkyl-triethoxysilanes after hydrolysis and polycondensation of the monomers leads to a three-dimensional network with strong adhesion to the surface by covalent and adsorptive bonding resulting in a serious increase in firmness and reduced elasticity (enhanced E-modulus). Consequently the treated zone differs from the untreated area in its stress-strain behaviour with respect to thermal

Keywords