Effect of Partial loss of Spray-on Protection on the Load Capacity of Steel Beams during a Standard Fire

Spray-on fire protection is widely used in protecting building members, such as beams, against fire. As this protective coating may be damaged during the service life of the beams, it is essential that the effect of this damage on the fire resistance of a steel beam be understood. A numerical study has been conducted to investigate the reduction in the cross-section moment capacity of protected steel beams exposed to the ISO 834 standard fire due to partial loss of spray-on fire protection. Hot-rolled I-shape steel beams according to CAN/CSA—G40.20/ G40.21-98 specifications are used in this study. Results of the study indicate that the reduction of cross-section moment capacity due to the partial loss of protection strongly depends on the area of the protection damage. The reduction of cross-section moment capacity is also affected by several other factors, such as damage shape, damage location, damage penetration, and the weight and depth of the steel section.