Gypsum plasterboards under natural fire—Experimental investigations of thermal properties

The use of fire protection materials is a common approach to ensure the fire resistance of steel elements exposed to fire. In this article, experimental investigations regarding the thermal behavior of gypsum plasterboards for steel elements exposed to natural fires are presented. Material properties, such as the specific heat, the thermal conductivity, and the density of gypsum plasterboards, have been investigated yet, but not especially for natural fire scenarios with different heating rates and cooling phases. For this purpose, experimental investigations of gypsum plasterboards under natural fire exposure are presented. Based on our own experimental investigations, the thermal properties of the investigated gypsum plasterboard for both the heating and cooling phases are demonstrated. Additionally, results from a large-scale fire test on loaded steel beams as well as unloaded steel columns protected with gypsum plasterboards are presented. The test results show a clear dependency on the heating and cooling rate. Furthermore, the thermal material properties change within the heating and cooling phase. So, the main objective of this article is to provide the thermal properties of selected gypsum plasterboard exposed to natural fires in the heating and cooling phases.