Materiales de Construcción, Vol 61, No 301 (2011)

Sulphide oxidation in ornamental slates: protective treatment with siloxanes

T. Rivas
Universidad de Vigo, Spain

J. Iglesias
Universidad de Vigo, Spain

J. Taboada
Universidad de Vigo, Spain

J. A. Vilán
Universidad de Vigo, Spain


In this work, we present the results of the measurement of the effectiveness of two silanes-siloxanes based products applied on roofing slates with the aim of slowing down the oxidation of the iron sulphide inclusions. The products were applied by immersion and spraying and also at different dilutions. The effectiveness of the treatments were evaluated by means of static contact angle measurements and water absorption coefficient variations; also, the durability under thermal cycles and the colour variations before treatment and before UVA exposition were tested. In all the cases, a very low product consumptions were obtained, due to the particular porous system of these rocks; also, any of the treatments increased the static angle. Nevertheless, the products tested remarkably increased the resistance of sulphides to the oxidation during thermal cycles without producing important changes in rock colour and also they have shown a good durability under UVA exposition


pyrrhotine; sulphide oxidation; silanes-siloxanes; slates; ornamental rocks

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