The relationship between temperature behaviors and section factors of fire spray protection coated composite beams exposed to standard fire

Concrete-steel composite beams, when they are exposed to high temperatures, it increases the quantity of heat inside the composite beams that restrain temperature rise caused by concretes. As a result, composite beams appear to have better fire resistance efficiency than regular steel beams due to the integrated structure between materials. In the case of composite beams, the temperature rise of steel exposed externally is directly related to the shape of sections and the degree of exposure. In this study, fireproof spray coat, approved as fire resistant construction for composite beams and regular steel beams, are coated in the same thickness and exposed to standard fire conditions. Then, the relationship between temperature history of steel and section factors of composite beams, derived from the fire resistance test result, is compared and analyzed. As a result, we came to a conclusion that the steel temperature measurement results and section factors per material are closely related, and it suggests that a standard approval of fire resistant construction can be widely used, instead of getting approval for each member, if relatively better performance can be predicted by distinct condition of fire resistance efficiency of members.