Simple chemical treatments for a successful consolidation of marble objects

This study focuses its attention on the chemical treatment of marble samples in order to create conditions for the protection of cultural heritage objects that consist of these materials. Water penetration, or its vapor condensation in the pores of these material leads to the formation of crystalline ice embryos, which depending on the environmental conditions create internal tensions and disrupt their micro-structure. Their consolidation was carried out by a three stages treatment, starting with 5 % calcium acetate solution for 60 minutes at 200 °C. The second stage occurs after a draining step at 700 °C and for 30 min, and involves the samples treatment with 5 % ammonium sulphate solution. After the application of the same draining procedure as previous, it followed with the third stage which includes the treatment with ammonium oxalate, followed by the same draining procedure. The marble samples were subjects of: 10, 20, 30, 40, and 50 treatments respectively, revealing each time weight increase. Their porosity and specific surface area, assessed by gas porosimetry measurements, continuously decrease at until the last treatment.

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