Impact of Accelerated Weathering on Fire Resistance Performance of Intumescent Materials

Abstract

The fire resistance performance of intumescent fireproofing materials for steel structure changes with time, as a result of exposure to environmental conditions especially temperature. The objective of this study is to investigate the impact of environmental conditions on fire protection properties (fire performance and char formation) of intumescent coating materials by using accelerated weathering technique. In this study a group of eight steel plates were coated with intumescent fireproofing of the same dry film thickness (DFT), the prepared samples were devided into two supgroups in which every supgroup of four specimens was exposed to ultraviolet radiation (UV) of wavelength (340 nm) for 0, 3, 6 and 9 years. The all intumescent coated samples were exposed to fire resistance tests in accordance with International test standard to evaluate their fire resistance performance. The formed char layers were characterized by using scanning electron microscopy (SEM). The results revealed insignificant change in the fire resistance for the 3 years aged samples. Increasing the accelerating aging over 3 years led to remarkable degradation of fire resistance. The SEM analysis revealed various foaming efficiencies as function of the exposure time.