Investigation of mechanical properties of steel reinforcements in reinforced concrete structures as a result of exposure to fire

Abstract

In this study, it is aimed to investigate the properties of the most commonly used metal and alloy steel materials, which are used in our country and in the world as engineering materials, under the influence of fire of the rebar in the concrete. Inspection standard TS 708:2010 S420 quality 8 mm diameter ribbed construction iron bars for 90 minutes in resistant furnace, atmospheric environment at 600 °C, 800 °C and 1000 °C concrete inside and outside the concrete at the specified temperature fire simulation, the process was allowed to cool in air. With the protective environment created by reinforced concrete, the temperature directly affecting steel bars located outside the concrete under the same conditions, The variable properties of the sample, which are inside the concrete and outside the concrete, were evaluated comparatively. Surface images of the specimens prepared in metallography were taken at different magnifications. The tensile strength of rebar bars did not change significantly according to the environment, but the samples in the concrete showed a more ductile tendency than the samples outside the concrete. The hardness values of the steel bars in the concrete and the steel bars other than the concrete decreased as the temperature increased and this decrease was higher in the samples in the concrete.