Among the Fire Protection in the interior representative case are spray coat, board, Paint. Intumescent paint has been developed that price competitiveness manufactures and Fire-resistances certificate was verified by experiment. Recent three-hour fire resistance performance developed Intumescent paint is applied as a high-rise, and major structures designed according to the refractory needs to be more efficient. However, domestic and outside the thermal properties of Intumescent paint materials are not proposed. Meanwhile, Intumescent paint in fire is built char layer since the 500∼60 0℃ and middle layer is formed by the decuple intumescent char more then cover thickness at room temperature. It is cut temperature flow off to the steel surface. Nonetheless, Bond Strength of steel and paint deprive as the intumescent char increases. and then steel surface are exposed to flame instantaneously. In this study, intumescent char estimate according to structural parameter(Fire resistance, cover thickness, shape ratio).

Structures of steel frame buildings getting vary depending on the development of construction technology. Fire-resistant steel beams and Columns accredited by accreditation bodies from the performance of various fire-resistant coating is applied to the current pillar method is most H-beams. H-beam has been proposed a non-load test specifications in the relevant regulations, its scope of accreditation to be granted without limitation of size H-beams from the performance of the test specification. However, in the case of the rectangular steel structure is to check its performance and to a separate one of the receive acknowledge and so take advantage of the cross-sectional shape factor in this study to test the performance of the fire-resistant structure proposed for standard test specimen.

Other countries(USA, Europe) have performed the fire resistance design of buildings by the alternative performance design methods, which are based on fire engineering theories. However, in Korea, the process on the alternative fire resistance performance design has only suggested without any applications for real steel structures. Therefore, In the case of steel structures stagnant research on refractory measures face difficulties in introducing fire resistance design. In this study, first of all, Intumescent paint was analyze the thermal properties(thermal conductivity, specific heat and density). In Sequence, using the section factor by H-standard section propose of section concrete filled steel tube and hollow. finally presents a reasonable thickness Intumescent paint takes time to target performance of the proposed cross-section steel tube.