Experimental study of UV/water-spray coupled hydrothermal accelerated aging on fire resistive of intumescent coatings for steel structures

In this paper, the durability of fire resistive performance of two types of water-borne intumescent coatings was studied using UV/water-spray and hydrothermal accelerated aging. Exposure conditions Type X intended for all environmental conditions with reference to ETAG-018-2 was used as the aging method. The aging effects and mechanism were preliminary analysed using fire test, adhesive test and X-ray Fluorescence spectrometer (XRF). The results show that after 2 stages of aging (for the intended use of 10 years), type-B coating shows better durability while type-A coating losses its basic performance of fire resistive and adhesion. Visually assessment and XRF results show that the aging is mainly caused by surface cracking and the precipitation of fire resistive components.