箱型鋼管混凝土柱之防火性能驗證技術研究

Abstract

若建築構件不能在持續高溫中仍具有承載能力，可能導致建築損壞或倒塌。國內中高層建築普遍採用之內灌混凝土箱型鋼柱(Concrete Filled Box Column, CFBC)須施作防火被覆，使達法規規定之防火時效。由相關研究顯示，無防火被覆CFBC 本身具有達25 分鐘之耐火時效，而基於永續建築結構考量，如能減少防火被覆，則可節省相對之建築耗材。再者，國外對於填充型鋼管混凝土柱(Concrete Filled Tubular Column,CFTC)研究，已有相當程度之成果，且各國也已於設計規範中，增列與修訂一套完整的建築構件火害設計準則、防火要求及防火時效之評估；而我國雖已有相關法規及條文規定部分建築構件之耐火要求，但對於CFBC 構件之耐火設計仍然不明確，且缺乏一套完整之火害設計準則及防火時效之評估方法。因此本研究將蒐集相關研究成果、以實驗探討內灌混凝土箱型鋼柱受火害之行為與防火時效，及研究不同參數所造成之影響，以供建立CFBC 火害設計準則與提出評估耐火時效之方法。 預期目標： 1. 建立箱型鋼管混凝土柱防火性能設計與驗證技術。 2. 依據不同之斷面尺寸、有效長度、加載強度等參數在軸壓下進行耐火試驗，並建立數值模型做比對，建立推導相關性能設計公式作為該類結構防火設計參考。 3. 於考量防火與結構安全前提下，經由性能設計後該類結構所用之防火被覆材減少甚至無須噴塗，可同時兼具經濟或環保效益。

collapse of the structures. Concrete filled box columns (CFBCs) are usually used in domestic median- and high-rise buildings. Fire protection is needed for CFBCs to achieve the fire resistance regulated by the fire design code. However, recent research found that CFBCs without fire protection can reach 25 minutes fire endurance. Based on the sustainability consideration, reducing use of the fire protection will benefit the saving of the building construction material. Moreover, the research results of the concrete filled tubular columns (CFTCs) in foreign countries are substantial. Fire design criteria and requirements, fire resistance assessment are supplemented in the fire design codes of the foreign countries. However, the fire design code, fire design criteria, and fire resistance assessment regarding the CFBCs are lack. Therefore, this research aims to study the test results in the literature, experimentally investigate the behavior and fire resistance, and to explore the effects of design parameters on fire behavior of the CFBCs. The results of this research will be used to establish the fire design criteria and to propose the assessment of the fire resistance. The objectives are as follows. 1. Establish fire performance design and verification technique of the CFBCs. 2. Construct fire test for axially loaded CFBCs with parameter of cross section dimension, effective length, and applied load level, perform the analyses to validate the numerical model, and establish the methodology for fire performance design which to be used for the basis of the fire design code. 3. Reduce the use of fire protection for CFBCs through the fire performance design by considering both the fire resistance and structural safety, and to benefit economy and environmental conservation.