Fire Resistance of Steel Structures with Epoxy Fire Protection under Cryogenic Exposure

Cases of fire with highly flammable, combustible liquids and combustible gases with high potential heat emission at oil and gas facilities are assumed to develop as a hydrocarbon fire, which is characterized by the temperature rising rapidly up to 1093 ± 56 °C within five minutes from the test start and staying within the same range throughout the test, as well as by overpressure being generated. Although various fireproof coating systems are commonly used to protect steel structures from high temperatures, a combination of fire protection and cryogenic spillage protection, i.e., protection from liquefied natural gas (LNG), is rather an international practice novelty regulated by standards ISO 20088. Thanks to their outstanding features, i.e., ability to sustain chemical and climatic impact, these epoxy-based materials are able to ensure positive fireproof performance for steel structures in the case of potential cryogenic impact. The article discusses tests on steel structures coated with epoxy fireproof compounds, specifically PREGRAD-EP, OGRAX-SKE and Chartek 2218. The test records show the time from the start of cryogenic exposure to the said sample reaching the limit state, as well as the time from the start of heat impact to the sample reaching the limit state in case of hydrocarbon fire temperature.

Effect of Bagasse Fiber As the Renewable Environmentally Friendly Material on the Properties of the Waterborne Intumescent Fireproof Coating

Bagasse was applied as fire-retardant filler to prepare the waterborne intumescent fireproof coating. The effect of bagasse on the properties of the fireproof coating was investigated by fire protection test, thermogravimetric (TG), scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), water resistance test and mechanical properties test. The result demonstrated the coating contained 1.5wt.% bagasse performed best in fire protection, thermal stability, oxidation resistance. Moreover, the char layer was dense and continuous. However, the fireproof coating contained 2 wt.% bagasse had excellent performance in water resistance test and mechanical properties test due to its properties of fiber. In addition, the components and chemical structure of char layer were characterized to study the flame retardant mechanism of bagasse in the fireproof coating.

Influence Factors and Prediction Model of Bond Strength of Tunnel Fireproof Coating under Freeze–Thaw Cycles

The freeze–thaw resistant performance of a tunnel fireproof coating (TFC) has an important impact on bonding property and durability. The influence of redispersible emulsion powder, polypropylene fiber and air-entraining agent on TFCs was studied. Transverse fundamental frequency and ultrasonic sound velocity were used to evaluate the damage degree of TFC, and the mechanism was revealed by SEM and pore structure. The results show that the most beneficial effect on bond strength of TFC is redispersible emulsion powder, followed by air-entraining agent, and then polypropylene fiber. After freeze–thaw cycles, the cumulative pore volume of micropores in the TFC increases obviously, while the porosity of macropores does not change significantly. A prediction model was proposed, which can calculate the bond strength from the damage degree of TFC under freeze–thaw cycles. The achievement can promote the application of TFC in cold regions.

Fire-resistance Rating of Square Steel Tubes and Concrete-filled Square Steel Tubular Columns Protected with Ultra-thin Fire-retardant Coating

To promote and criterionize the application of ultra-thin the fireproof coating s to building structures, four concrete-filled square steel tubular (CFSST) pillars as well as two square steel tubes, each protected along with ultra-thin the fireproof coating , were subjected to full-scale fire tests to investigate their fireproof level on the basis of the ISO 834 criterion time�degrees curve. Test results revealed not only the temperature variation characteristics of specimens suffered from inconsistent fire exposure, but also effects of the steel ratio of the test specimen and the number of fire-exposed sides on the fire-refractory level of the test specimen. Test results demonstrated that when protected with an ultra-thin the fireproof coating , the heating rate of the specimens was considerably lower than that of the test furnace, suggesting that the ultra-thin the fireproof coating exhibits good thermal insulation performance. The test results were compared with China�s current criterions for the fire-refractory level of square steel tubes and CFSST pillars, indicating that the criterions would lead to a relatively conservative fire-safe design for four-side fire exposure.