고온에 노출된 중공슬래브의 온도분포 추정방법

Abstract

화재로 인해 열적 손상을 받은 철근콘크리트 구조물의 잔존 강도를 평가하기 위해 다양한 연구가 진행되었다. ACI 216 및 Eurocode에서는 부재 형태에 따라 단면 내 온도분포를 산정할 수 있는 방법을 통해 열적 손상을 받은 철근콘크리트 부재의 강도 감소를 정의하고있다. 이러한 방법은 부재 내 온도분포를 정확히 추정하여야만 가능하며, 구조형식 및 재료적 특성이 변화될 경우 적용성은 의문시 된다. 본 연구에서는 중공 슬래브를 대상으로 기준에서 제시하고 있는 온도추정식의 적정성을 평가하고자 하였다. Generally, the reinforced concrete slab has great fire resistance performance because concrete has excellent thermal material properties under fire. But, in the case of hollow slab, it will be expected that hollow slabs have different temperature distribution and fire endurance performance compare to reinforced concrete slab. Because hollow slab has internal void space that occurs decreasing regenerative effect of concrete and formation of internal air layer. Evaluation method for fire resistance performance of hollow slabs was proposed using wickström’s method. For the casual use of evaluation, simplified method was proposed which was limited to solid slab and donut type hollow slab which was developed by authors of this research paper. Also, verification on proposed method was performed by comparing results of fire experiment for hollow slab and evaluation results. Proposed method of the results of this study was possible to predict the residual strength and temperature distribution of slabs under fire.