Study and Prediction for the Fire Resistance of Acid Corroded Intumescent Coating

Abstract

Acid corrosion may cause the deterioration of the fire resistance of the intumescent fire retardant coatings, especially for the coatings used in the acid polluted environment. This paper reported the results of an experimental study of degradation in fire protection performance of intumescent coating for steel elements after different times of immersion in the hydrochloric acid solution. After acid erosion, the thickness of the coating thinned, the surface became rough and had cracks and broken holes. The size of the pores in the char layer was larger and uneven, and some 'cement' parts were formed in the char layer. The TG/DTG results showed in the low temperature stage the curve was relatively flat. In the medium temperature stage, the number of the weight loss troughs decreased; the shape of the troughs simplified; and the top weight loss rate increased. In the high temperature stage, the troughs near 593 °C flattened gradually, and the top weight loss rate became smaller, while the top weight loss rate became larger around 674 °C. And there were significant changes in the thermal dynamic parameters. A prediction method of remained fire resistance property for the acid erosion coatings was proposed, by comprehensively considering the physical and chemical characteristics change trends of the corroded coating. And this method can be a reference for the fire safety evaluation of the built protected steel structure.

Fire-Resistance Testing Procedures for Construction Elements—A Review

“…Ji et al conducted a fire-resistance test in small-scale testing furnace. In this setup, two thermocouples were attached to measure the back side temperature and to monitor the furnace temperature [30]. Similarly, Cutter et al developed a novel small-scale fire-resistance test method.…”

Recent developments of intumescent fire protection coatings for structural steel: A review

“…The coating becomes uneven and thin, with large pore size and cracks, holes and rough surface morphology, and decreases fire-resistant performance of coating after acid corrosion. 178,179…”

Comparing the effect of nanoclays on the water-resistance of intumescent fire-retardant coatings

“…Despite their versatility, manufacturability in the application, aesthetic characteristics, intumescent-type coatings have a series of disadvantages. First of all, it is low atmosphere resistance [3] and resistance to aggressive environments [4], and, accordingly, a limited service life [5]. The authors of work [6], for example, found that after 30 years of natural aging under the climatic conditions of Italy, intumescent coatings lose their fire protection functions completely.…”

“…This is primarily due to the lack of procedures for modeling the conditions of artificial aging for a coating. There are also no adequate criteria for determining the fire-protective properties of the coating after aging, followed by forecasting its service life [4,5]. National and international standards, for example [20], to some extent define methodological approaches to determining the durability of reactive coatings.…”