以小尺度鋼鈑取代鋼樑進行被覆材料耐火性能之評估

唐益楚

[中文摘要]

被覆鋼骨構造耐火性能係以耐火時效(t)加以認定，而耐火時效又與鋼材的斷面尺度因子(W/D、單位重/斷面受火週長)以及被覆材料厚度(T)有著密切關連。本研究採用斷面尺度因子轉換的觀念，將工程上常見不同尺寸之H型鋼骨構件展開成為45公分見方不同厚度的鋼版後加以被覆，製成小尺度試體，並以 CNS 12514所規定之火災標準燃燒溫度曲線對小尺度試體進行單向度加熱模式的實際耐火試驗，以瞭解t、T及W/D間的實際關係。而後配合理論分析檢討以小尺度試體取代實際被覆鋼骨構件進行耐火性能評估之可行性。由於被覆鋼骨構造種類繁多，故僅先針對H型斷面施做無中空層之濕式被覆樑構件(水平加熱)模式進行探討。
        研究結果發現，多向度受熱的被覆鋼骨樑構件確實可依斷面尺度因子轉換成為單向度受熱的小尺度試體進行耐火性能評估，但需考慮兩者間水份蒸發情況不同及高溫時小尺度試體熱損失的影響。而在t、T與 W/D三者關係中，t值分別與T及W/D呈穩定之正比關係，經由此一發現，本研究針對目前廣受引用之樑用被覆材料厚度轉換公式；以及我國建築主管機關對國外測試合格被覆材之審核認可管理辦法，提供了改進及審核依據方面的實質建議。

[英文摘要]

The fireproof capacity of coated steel structure is maintain by fire resistance rating(t), and the rating is close to section scale factor (W/D, unit weight/section fired  circumambience) of steel structure and coating material thick ness(T). The study is according to the view of section scale factor transfer, put all kinds of H style to be 45cm2 but differ thickness steel plate, make to small scale specimen, therefore, applying standard curve time-temperature under CNS 12514 to proceed truly fire resisting test of single degree heated model for small scale specimen ,and realize the truly relationship of t, T and W/D. However, according to theory analysis the feasibility of using small-scaled specimen replace coating steel structure and proceed the appraise of fireproof capacity. The kinds of coating steel structures are so much, so only study the model of wet coated structure (horizon-heating) painted around H style section.@　The study result detect that the mutidegree coating steel beam structure will transfer single degree small scale specimen and proceed fire resisting test by section scale factor, but must consider water evaporate condition and the affect of small specimen lost heat in high temperature. During the relationship of t, T and W/D, t is proportional with T and W/D. Form the result, the paper point of sprayed thickness of beam transfer formula common using now, and the managing method for examining the external qualify materials that recognized by the domestic authorities concerned, to provide the actual suggestion for the accordance of improving and examining.