Nitrifying bacteria on the asbestos-cement roofs of stable buildings
| Autor: | Zdeněk Zadák, Jaroslav Novotný, Richard Wasserbauer |
|---|---|
| Rok vydání: | 1988 |
| Předmět: |
animal structures
Materials science biology Waste management Metallurgy technology industry and agriculture General Engineering biology.organism_classification Asbestos cement Ammonia chemistry.chemical_compound chemistry Nitrifying bacteria embryonic structures Degradation (geology) Nitrification Porosity Roof Water vapor |
| Zdroj: | International Biodeterioration. 24:153-165 |
| ISSN: | 0265-3036 |
| DOI: | 10.1016/0265-3036(88)90045-0 |
| Popis: | The disintegrated asbestos-cement roofs of agricultural buildings were subjected to chemical and microbiological analyses, supplemented simulating the degradation effects of single environment factors in a conditioning chamber, type Brabender KS 500/90 (FRG). The results have given evidence that nitrifying bacteria are a dominant factor in the degradation of asbestos-cement. Metabolic processes of these bacteria cause the chemical corrosion of the roofing material which results in asbestos-cement being attacked by nitrous and nitric acids or by ammonia salts of these acids. Water vapour which evaporates from a stable building penetrates the roof insulating layer and condenses on the lower face of the corrugated asbestos-cement slabs, washing soluble CaNO 2 and CaNO 3 out of the roofing material. The result is an increased porosity and reduced strength of the asbestos-cement. Water vapour which infiltrates into capillaries and pores of the weakened roofing generates pressures that destroy the roof during the transformation of water vapour into ice. |
| Databáze: | OpenAIRE |
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