Earticle

초록

영어

Reinforced concrete (RC) structures strengthened using conventional techniques such as steel plates or fiber-reinforced polymers (FRP) often exhibit significant vulnerability under fire conditions, which are among the most critical structural disasters, due to rapid thermal degradation and loss of bond performance. In this context, ultra-high performance concrete (UHPC) jacketing has emerged as a promising strengthening method for enhancing disaster resilience owing to its superior mechanical properties and non-combustible nature. However, conventional UHPC remains susceptible to explosive spalling and thermo-mechanical degradation at elevated temperatures. To address these limitations, this study investigates the fire performance of RC beams strengthened with thermally enhanced UHPC (TE-UHPC) incorporating coal bottom ash and hybrid fibers. Full-scale fire tests were conducted on TE-UHPC beams, normal-strength concrete (NSC) beams, and composite beams strengthened with TE-UHPC jacketing under combined mechanical loading and ISO 834 standard fire exposure. The results showed that TE-UHPC exhibited improved thermal insulation performance, resulting in a slower temperature rise within the cross-section than conventional UHPC. Although TE-UHPC beams alone demonstrated lower fire resistance than NSC beams, the application of TE-UHPC jacketing significantly enhanced fire performance, achieving approximately 12% greater fire resistance than unstrengthened RC beams. A finite element model was developed and validated against experimental results, showing excellent agreement in both thermal and structural responses. Parametric analyses revealed that fire resistance increases linearly with jacketing thickness and decreases logarithmically with increasing load level, while TE-UHPC consistently outperformed conventional UHPC due to its reduced thermal conductivity. Based on the numerical database, simplified predictive relationships were established to support performance-based fire design of strengthened RC members. The proposed approach provides an efficient and disaster-resilient strengthening strategy for RC structures exposed to fire hazards.

저자

• Ho Jin Lee [ Korea University; Korean Society of Disaster Information; Kumoh National Institute of Technology ]
• Tae Hwan Kim [ Korea University; Korean Society of Disaster Information; Kumoh National Institute of Technology ]
• Il Young Jang [ Korea University; Korean Society of Disaster Information; Kumoh National Institute of Technology ]
• Young Soo Yoon [ Korea University; Korean Society of Disaster Information; Kumoh National Institute of Technology ]

참고문헌

발행기관

간행물

표지보기 관심저널 등록

• 간행물명

  한국재난정보학회 학술발표대회

• 간기

  부정기

• 수록기간

  2005~2026

• 십진분류

  KDC 338 DDC 361