Techstroyinvest: new technologies for restoration work

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In restoration work the preparatory stage is of special importance, it represents clearing of the surface for the most part. The principal requirement is preservation of the authors layer. The usual methods of clearing the surface in restoration include surface treatment with chemicals, mechanical clearing and neutralization of chemical substances applied. These methods are quite expensive due to high cost of chemical reagents and tedious manual labour of specialists having high qualification. For that reason the company specialists developed a unique method of jet blasting of surfaces (not to be confused with sand-jet method!). It is intended for removal of oxide, saline, organosilicon and paint coating. This technology provides a possibility of refined cleanup for surfaces made of metal (with sheet thickness from 0,8 mm), concrete, granite, marble, limestone, shell rock, sandstone, without affecting their natural geometry and oversaturating the materials with moisture. In brief, the nature of jet blasting is reduced to the following. The air is accelerated to the level of sonic speed multiplied by 2,53. The initiating element is included in it some fine-dyspersated substance. It may be a claydite dust, cowper slag, sand or any other material with a fraction of 1030 micron. It is dragged into the air flow and is accelerated to great speed. Getting into a zone of hyperpressure formed near the very surface the abrasive is split into even smaller particles. The latter reaching the surface initiate micro-explosions on it resulting in break-off of coating fragments. This way all layers not bound with the substratum by valence bond go off. The technology developed by specialists of Techstroyinvest company has proved its advantages in the clearing of coatings. The most challenging approbation of the method was the work with famous sculptures by P.K. Klodt Horse-tamers erected in the Anichkov Bridge. Using the jet blasting all later layers were removed, and the restorers were able to proceed to their laborious work after it. It was the first application of the new technology at such a complicated and responsible project. The Horse-tamers was the firstling in the list of subsequent major projects implemented by Techstroyinvest. The restoration of sculptural group The Chariot of Glory crowning the arch of the General Staff Headquarters have been completed already as well as the clearing of Aphrodite Saint-Gally a very complicated in terms of technology (removal of copper applied in galvanic way on the cast-iron sculpture). The talks on a number of projects of municipal importance are in process. The specific peculiarity of the company is that it has no standard projects. The work is different all the time. All objects to be restored are important, responsible and need individual, original approach. All the workers of the company deal with monuments of history and architecture. The principal approach is typical for restoration workers: the key task is not to make it worse. The projects are extremely complicated, especially from the point of view of preparation to renovation. High professionalism of the specialists of Techstroyinvest is a guarantee of individual approach to every project and of efficient, high-quality work. Apart from the basic line of work preparation of monuments to restoration using jet blasting of coatings the company offers cleanup of surfaces of all kinds from any coatings or layers using other methods. 51, Pr. Obukhovskoy Oborony St. Petersburg, 193029 Russia Tel./fax +7 (812) 567-2886

: 12.11.2002

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