ALKOXYSILANES AND THE CONSOLIDATION OF STONE PDF
Get this from a library! Alkoxysilanes and the consolidation of stone. [George Wheeler; Getty Conservation Institute.]. Stone is one of the oldest building materials, and its conservation ranks as one of the most challenging in the field. The use of alkoxysilanes in the conservation. Permalink: ; Title: Alkoxysilanes and the consolidation of stone / George Wheeler ; with annotated bibliography by.
|Published (Last):||7 June 2014|
|PDF File Size:||7.46 Mb|
|ePub File Size:||6.40 Mb|
|Price:||Free* [*Free Regsitration Required]|
Further applications should normally take place until no more is taken up. Two water spray cycles per day were applied for two months, and later on walls were allowed to weather naturally.
This wrapping must be kept in place from several days to a week depending on the case. The choice of solvent to be used with epoxides is also very important. C — — Modulus of Rupture.
Since then, silane has been used to refer to many of the monomeric organo-silicon compounds including ethyl silicate. The percent acid-soluble contents of untreated masonry samples 44 is determined to identify the masonry’s vulnerability to acid-related deterioration when exf osed to acidic precipitation. Fassina, Stone Decay and Conservation: Zagreb, October Although initially no failure in the use of barium hydroxide consolidayion on calcareous 8 stone was reported by Church, the treatment later met considerable criticism from other conservators.
The amount of penetration and actual impregnation resulting after the solvent evaporates depend on the choice and amount of solvent used. Field trials do not provide much information consolidaiton the short term about the preservative effect of the treatment; nevertheless, they are valuable for the practical experience they provide.
Alkoxysilanes and the consolidation of stone
It has been used for centuries to treat limestone. Also, this method is of no use on buildings. An alkyl group is a compound of carbon and hydrogen atoms, such as methyl – CH3 and ethyl -C2H5 groups. The better result was obtained with Stone Strengthener H in a mineral spirits solvent rather than the ketone solvent.
Laurie obtained a British patent for the use of silicic ether in stone consolidation.
Bulk infiltration is a technique whereby holes are drilled into the wall and funnels are al,oxysilanes to deliver consolidant to a substantial depth where impregnation is obtained. During the period from tohydrolised derivatives of ethyl silicate, which were broadly studied, interested chemists in a variety of industries, such as the manufacture of paints, coatings, fire-proof textiles, impregnating agents for preservation of stone, brick or woodwork, etc.
In addition, the impregnated wax can rarely be removed when there is a need for application of other materials. According to Helmut Weber, repeat application after one or two weeks is an effective method of consolidation treatment, as well as continuous spray applications. Torraca, ” General Philosophy of Stone Conservation, ” p. One of the most important properties of alkoxysilanes is their ability to penetrate deeply into porous stone.
Treatment was said to be irreversible, but reappUcation is possible. Getty Conservation Institute,pp. Deeper penetration can be achieved with monomer solutions, since they are less viscous than the diluted polymer resins and the size of a monomer molecule is very small. They both have been used for stone consolidation, even though their structure is fundamentally different.
Alkoxysilanes and the Consolidation of Stone
It must be non-corrosive and harmless in use. In Italy, a mixture of magnesium and zinc fluorosilicates has been used for the restoration of several stone monuments by P. Several authors have suggested that a stone consolidant should penetrate to such a depth that all the deteriorated zone is solidified and attached to the unweathered sound core of the stone. The authors suggested that it was the presence of heavier hydrocarbons in the solvent which provided additional water hairier and repellency properties.
Therefore, complete filling of the pores with an organic hydrophobic consolidant is not recommended. This compound is chemically similar to ethyl silicate except for the substitution of a methyl group for one ethoxy group. There will never be an ‘ideal’ material in the field of stone and adobe consolidation, because one can not expect to formulate one single system for a wide range of problems.
Ethyl silicate is the best known alkoxysilane, also referred to as tetraethoxysilane. Deposition allkoxysilanes magnesium fluorosilicate salts forms a whitish color on the treated stone.
Dynamit Nobel AG Th. Nicholas Copernicus University Press Department, Inlarge scale field tests with partially polymerized ethyl silicate were done in the Seleucia area and in Hatra.
There is clearly a need for more research on the retreatment of consolidated masonry and earthen materials in order to provide answers to these and related questions. Water is responsible for alkoxysilwnes damage in climates where freezing temperatures can occur.