REVERSED BEAM FIREPROOF STRUCTURE

PROBLEM TO BE SOLVED: To provide a reversed beam fireproof structure capable of promoting heat radiation from a steel beam on an upper story while reducing heat input into the steel beam on the upper story from a fire disaster room on a lower story.SOLUTION: A reversed beam fireproof structure 1, to which the present invention is applied, comprises a steel beam 2 that is provided in a beam material of a building 8 and continuously provided upward from a floor slab 4 on each story, and a fire resistive covering part 3 that is formed by applying predetermined fire resistive covering to the steel beam 2. In the steel beam 2, the fire resistive covering part 3 is arranged on the lower side β of the steel beam 2, and a reduced fire resistive covering part 20, the fire resistive covering of which becomes less than that of the fire resistive covering part 3, is arranged on the upper side α of the steel beam 2.SELECTED DRAWING: Figure 11 【課題】下階の火災室から上階の鉄骨梁への入熱を低減させる同時に上階の鉄骨梁からの放熱を促進させることのできる逆梁耐火構造を提供する。【解決手段】本発明を適用した逆梁耐火構造１は、建築物８の梁材に設けられるものであり、各階の床スラブ４から上方に連続して設けられる鉄骨梁２と、鉄骨梁２に所定の耐火被覆が施されて形成される耐火被覆部３とを備える。鉄骨梁２は、耐火被覆部３が鉄骨梁２の下部側βに配置されるとともに、耐火被覆部３よりも耐火被覆が削減された減耐火被覆部２０が鉄骨梁２の上部側αに配置される。【選択図】図１１