The Dynamic and Flexural Behavior of Coated GFRP Rebars after Exposure to Elevated Temperatures

The dynamic and flexural behavior of pultruded glass fiber reinforced polymer GFRP rebars were investigated after exposure to elevated temperatures ranging from room temperature to 290 °C. The rebars were cut and grouped into two sets. The first set contained the uncoated specimens, and the second set enclosed the specimens that had been coated with a gun-sprayed thin layer of silicon matrix mixed with ceramic nanoparticles as an insulation medium. All specimens’ dynamic and flexural performances were experimentally performed after heating them inside the oven for 6 h and later cooled down outside the oven at room temperature for 24 h. The dynamic results of the coated specimens showed slight changes in the damping ratio due to the effectiveness of the coating layer. In contrast, the uncoated specimens showed a gradual increase in the damping ratio ranging from 12.5% to 43.1%. Similarly, the tested flexural strength of the coated specimens provided slight changes within the elevated temperatures, while the uncoated specimens showed a gradual decrease ranging from 3.9% to 6.4%.