The current technology for sprayed concrete cannot do without various types of concrete admixtures allowing that more demanding requirements for quality and overall characteristics of Sprayed Concrete can be met. These are mainly concrete plastificators and set acceleration admixtures. In practice these technologies are employed especially in construction of underground structures where the working conditions are often very restricted. In these days Sprayed Concrete is usually applied by wet spraying where the fresh concrete is made in a batching plant and then transported to the construction site. That is why it is also important to pay attention to rheology characteristics of sprayed concrete. The concrete is then placed by a special spraying plant while it is ensured that all requirements and technical specifications for sprayed concrete are complied with. The characteristics are most affected by the admixtures - both plastificators and accelerators and their compatibility with cement. In order to acquire new evidence in the field of sprayed concrete technology and use of admixtures and their effect in relation with various types of cement a number of combinations of admixtures and cements were tested. Gradually results were obtained and recorded for rheology of cement mortars and concrete, for characteristics of young sprayed concrete mixes and for the comparison between the laboratory tests and findings from daily practice.
Identifer | oai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:392284 |
Date | January 2012 |
Creators | Hela, Vlastimil |
Contributors | Brožovský, Jiří |
Publisher | Vysoké učení technické v Brně. Fakulta stavební |
Source Sets | Czech ETDs |
Language | Czech |
Detected Language | English |
Type | info:eu-repo/semantics/doctoralThesis |
Rights | info:eu-repo/semantics/restrictedAccess |
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