Cit:Lubelli.etal:2014a
| Autor | Lubelli, B. and van Hees, R.P.J. and Nijland, T.G. and Bolhuis, J. |
| Jahr | 2014 |
| Titel | Effect of ethyl silicate on salt crystallization resistance of Maastricht limestone |
| Bibtex | |
| DOI | 10.5165/hawk-hhg/260 |
| Link | Datei:19 SWBSS-2014 Lubelli etal.pdf |
| Bemerkungen | In: De Clercq, Hilde (editor): Proceedings of SWBSS 2014. Third International Conference on Salt Weathering of Buildings and Stone Sculptures Royal Institute for Cultural Heritage, Brussels, Belgium, 14-16 October 2033, S. 371-387 |
Eintrag in der Bibliographie
Keywords[Bearbeiten]
Maastricht limestone, ethyl silicate, salt crystallization test, analogues for decayed stone.
Abstract[Bearbeiten]
Consolidant treatments aim to re-establish the cohesion in decayed materials showing decay patterns as sanding or powdering. Ethyl silicate (TEOS) is the most used type of consolidant for inorganic porous materials in the last 30 years. This product, which works through precipitation of silica gel in the pores of the material, is known to have a good chemical compatibility with siliceous substrates (sandstone and brick), but much less with lime based materials as limestone and mortar. In order to encounter this shortcoming, in the last years, research has been focused on the modification of ethyl silicate products to make them more compatible with lime-based substrates. In this study the effect of an ethyl silicate product, commercialized for application on limestone, has been investigated. The research concerned more specifically the resistance of Maastricht limestone with respect to salt crystallization. The penetration depth and the strengthening effect of the treatment have been assessed, using respectively dithizone and the Drilling Resistance Measurement Method (DRMS). Further the influence of the treatment on water absorption and drying, measured by standard test procedures, has been assessed. An accelerated salt crystallization test has been carried out to assess the effect of the treatment on the salt resistance of the Maastricht limestone. All tests have been performed on fresh stone as well as on artificial analogues for decayed stone, obtained by re-aggregating the original stone following a method developed by the authors. The results showed that the studied ethyl silicate product is able to reach a very good penetration depth in the Maastricht limestone and to confer a significant strengthening to the substrate, without significantly altering the overall drying behavior of the material. However, a not homogenous distribution of the product and of its strengthening effect in the impregnated zone has been measured. This has, for the salt crystallization test on specimens with the re-aggregated layer, caused salt accumulation behind the outer zone, enriched in ethyl silicate, which consequently resulted in the detachment of this 2-3 mm thick layer. The differences in extent and type of damage observed during the crystallization test between fresh stone and re-aggregated stone specimens underline the necessity to test consolidant products on (artificially) decayed and not on fresh substrates in order to obtain reliable results.