Examination of concrete strength and microstructure after fire by computed tomography
Abstract
In this study we examine the effect of high temperature on the concrete strength and on the concrete matrix, including chemical changes and the cracks. During the experiments we tested the compression strength, the flexural tensile strength and the body strength of 7 different concrete mixtures after fire load. The applied temperature steps were 20, 50, 150, 300, 400, 500, 800 ° C. During the fire load the density of the specimens changed, because at high temperatures the porosity of the concrete and the number of the cracks increase. Therefore, our experiments were complemented with computed tomography (CT) tests. During the tests, we proved that CT tests are clearly suitable for monitoring of material structural changes in case of concrete.
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