How does concrete strength affect fire resistance?
Abstract
At first, it may seem contradictory that higher concrete strengths can degrade fire resistance of building structures. However, if the strength of the concrete exceeds an upper limit, the probability of concrete surfaces becoming detached increases. During prefabrication, structural elements are often produced with greater strength than planned. Higher concrete strengths generally do not cause a decrease in load-bearing capacity, but can be a serious problem when sizing for fire load. During the research, two prefabricated elements were tested: a TT panel and a single-wall panel. During the test, a reference element (currently in production) and a component made with a
modified concrete composition were compared. In the modification, structures were tested by adding plastic fibers to prevent the layering of concrete. As a result of our experiments, we recommend making stricters standards. It has been proven that in order to ensure the fire safety of reinforced concrete structures, it is necessary to require the addition of plastic fibers even in the lower concrete strength class and to introduce an upper strength limit from the aspect of fire safety.
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MSZ prEN 1365-2:2012
Eurocode 1 (2004) prEN1991-1-2:…... Comité Europeén de Normalisation (CEN),
Brussels
MSZ EN 206
MSZ 4798
