Mechanical properties of sandstone improved by impregnation with stone consolidation products

Sandstones and arkoses are traditional building elements of masonry for many historical buildings in the Czech Republic. There is an endeavour to preserve the original material and to extend the life of a stone, particularly for historically, architecturally and monumentally valuable objects. In the renovation practice, a damaged stone is impregnated with liquid agents which feed a new binder (paste) to the voids in a stone. After curing of the binder, the mechanical properties of the stone restore their authentic values. In the present study, several consolidants were tested from the viewpoint of their effect on selected mechanical characteristics of arkosic sandstone. Especially were investigated the consolidants based on ethylsilicate, and specifically the effect of an elasticised component in ethylsilicate agens on the consolidation of a stone. The degree of consolidation of a stone after the impregnation of notched and un-notched prisms was examined experimentally. It can be considered that notched prisms roughly approach the state of a stone with a crack. It was found that the use of the consolidating agent REMMERS KSE 300E is superior over other agents in compensating the effect of the crack. Beside this product the experiments also proved a positive effect of treating the sandstone with a crack by a 5% solution of an acrylate copolymer Paraloid B 72.