KATEGORYZACJA ZNISZCZEŃ SPOWODOWANYCH PROCESAMI WIETRZENIA MATERIAŁU BUDOWLANEGO NA PRZYKŁADZIE ZAMKU ŚWINY NA DOLNYM ŚLĄSKU

Świny castle is situated within Kaczawskie Mts. in Lowe Silesia, about 3 kilometres north to Bolków. It is built of broken stone, mainly ryolites and ryodacites, moreover conglomerates and greenstones. Portals and window frames are made of upper Cretaceous cut sandstone. In the paper there are presented works basing on the classification scheme of weathering forms, damage categories and damage indices for natural stone building materials, which was evolved by international research group from Aachen: “Natural stones and weathering”. Within the investigations, the selected parts of castle walls and portal were mapped, including lithological mapping and weathering forms mapping. The most serious weathering processes could be observed on ornamental building units made of sandstone. This rock weathering consists on roughness, caused by the loss of the finest grains. The following consequence is dust and sooth precipitation on the outer parts of rock elements. The loss of the stone material is also due to the stone structure (lamination) and on the outer edges (rounding). Taking into account the other litological types of building stones in the castle walls, the conglomerates are seriously damaged, as well. It is caused by loss of the pebbles, because of rock cement embrittlement. The deterioration of ryolites is caused mainly by their shale structure. On the outer parts of the building blocks and mortar there are crusts and salt efflorescences. Their components are some weathering products, such as sulphates: gypsum, selenite, arcanite, thenardite; and nitrate – nitrokalite.