Compared to steel of the same weight in steel concrete structures, fiber reinforced polymer (FRP) is known to have greater strength and better resistance to corrosion. As such, it is being proposed as an effective structural material. Despite its many advantages, FRP has not been rapidly adopted in civil structures. This is because it is more expensive, prone to brittle fracture, and has weak fire resistance. To examine changes in the mechanical properties of FRP and the effectiveness of fire resistant coating, this study conducted tensile tests on coated and uncoated specimens over varying temperature. Glass fiber has excellent fire resistance since it does not melt or burn at high temperatures. However, epoxy is unable to withstand exposure to temperatures exceeding the transition temperature, thus leading to unsatisfactory structural performance and fire resistance. This study investigated the behavioral changes in FRP by exposing the specimens to temperatures ranging from room temperature (approx. 25℃) to 300℃, so as to improve the fire resistance of epoxy.

In this study, to evaluate the performance of fire resistance of the mortar with magnesium hydroxide(MH) and aluminium hydroxide(AH) which has a RCC (Radiant Control Capability) as repair material to the steel structure, temperature evaluation of mortar was conducted by increasing 500°C in the furnace. The performance of RCC can decrease a temperature to external and internal mortar. As a result, it is confirmed that temperatures of mortar with magnesium hydroxide(MH) and aluminium hydroxide(AH) were more decreased than general mortar due to the RCC effect of MH and AH. Therefore, it can be possible to apply to a repair material at the steel structure.

본 연구에서는 우선 화재에 노출된 고강도 콘크리트의 내화특성과 폭렬 메커니즘을 규명한 기존 국내외 연구자들의 연구문헌들을 심도 깊게 고찰하였다. 그 후 고온을 받은 고강도 콘크리트에 대한 국내외 연구자들의 주요 실험 변수를 분석하여 가장 최적의 변수를 설정하였으며 이를 토대로 하여 100MPa급 고강도 콘크리트의 내화 특성을 규명하기 위한 내화실험을 계획하였다. 또한 기존 연구의 실험결과를분석한 결과 폭렬방지에 효과가 있는 것으로 알려져 있는 PP섬유와 친수성 재료로서 시멘트 입자와 부착성능이 우수하고 워커빌리티를 개선할 수 있는 NY섬유를 혼합한 신재료 HB섬유를 섬유혼입률 0.05%로 정해 배합설계에 반영하였다. 이러한 배합설계로 타설한 총 48개의 공시체를 28일 양생기간 후 온도변화 (100℃~700℃)에 따른 고강도 콘크리트의 역학적 특성을 분석하기 위해 화재를 받은 후 냉간상태에서의 내화실험을 수행하였으며 이를 통해 고강도 콘크리트의 내화 특성을 분석하였다.