# Effect of Fireproof Coatings on the Post-Fire Behavior of CFRP Composite Sheets
## 1 Introduction
Furthermore, this process triggers the emission of smoke, soot, and harmful volatile substances into the surrounding environment. After exceeding the decomposition temperature, it is generally impossible to restore the original mechanical properties of CFRP composites through cooling [4; 22; 23; 24; 25; 26]. Various studies have investigated the impact of high temperatures on CFRP materials. In the research conducted by [PERSON] et al. [5], an experiment was performed on the FRP bars to investigate the temperature impact on the elasticity modulus and strength. Their findings revealed that CFRP bars experienced a 47% decrease and a 71% reduction in elastic modulus and strength after being exposed to 375 \({}^{\circ}\)C. [PERSON] and [PERSON] [25] explored the influence of temperature on the tensile mechanical properties of NSM CFRP rods and strips. Their results highlighted a significant decline in these properties beyond the threshold of 300 \({}^{\circ}\)C. Furthermore, [PERSON] et al. [17] delved into the mechanical performance of pultruded carbon fiber-reinforced polymer plates under high-temperature conditions. Their outcomes revealed a pronounced decrease, reaching 50% of the strength at 300 \({}^{\circ}\)C and further diminishing to 7% at 700 \({}^{\circ}\)C. [PERSON] et al. [27] examined the impacts of high temperatures on both the physical and thermal performance of CFRP bars. Their study demonstrated substantial reductions of approximately 50-70% in the ultimate tensile strength of CFRP bars at an extreme temperature of 450 \({}^{\circ}\)C. [PERSON] and [PERSON] [28] conducted comprehensive experimental research to investigate the strength and stiffness performance of CFRP composite bars at high temperatures. Their investigation indicated that the stiffness of CFRP bars at temperatures below 350 \({}^{\circ}\)C was about 90% of the initial stiffness, and the strength diminished to approximately 35% of its initial strength at around 350 \({}^{\circ}\)C.  
To mitigate the adverse effects of fires on CFRP composites and ensure structural safety, it is essential to identify suitable fireproof solutions. Numerous research endeavors have explored various methods to reduce the influence of high temperatures on CFRP composites, includingusing flame-resistant materials, adding macro and nanoparticulate additives to the substrate, and applying ceramic heat barriers and fireproof coatings. [PERSON] et al. [19] performed tensile tests on the CFRP sheets covered by intumescent fire retardant paint. Their findings indicated that the unpainted CFRP sheets experienced a 67% reduction in tensile strength, while the painted CFRP sheets exhibited a 60% reduction at 600 \({}^{\circ}\)C. [PERSON] and [PERSON] [29] examined the fire resistance of a variety of high-temperature-resistant CFRP tendons. Their findings showed that the strength endured at 78% when subjected to 200 \({}^{\circ}\)C, and the elastic modulus maintained a level of 82% at 300 \({}^{\circ}\)C. [PERSON] et al. [30] showcased the effectiveness of intumescent paint in preventing the deterioration of the mechanical performance of CFRP bars within the temperature range of 350-600 \({}^{\circ}\)C. In addition, [PERSON] et al. [31] explored the influence of incorporating ammonium polyphosphate (APP) as a fire-retardant filler on the mechanical properties of CFRP composites. The experimental results revealed that, with increasing exposure temperatures, the strength degradation rate of composites containing APP filler was significantly lower than that of composites without this filler. [PERSON] [32] prepared a new environmental fire-retardant polymer nanocomposite using a recycled polyester matrix and Mg(OH)\({}_{2}\) nanofiller. The findings revealed that the nanocomposite exhibited high fire retardancy performance. Furthermore, [PERSON] et al. [33] studied the thermal behavior of a carbon fiber composite infused with boron carbide nanoparticles. The experimental data suggested that the inclusion of boron carbide improved the thermal stability of the composite.