Investigation of the seismic performance of a fire-exposed reinforced concrete frame with shaking table tests


AKBULUT Y. E., SUNCA F., ALTUNIŞIK A. C.

Proceedings of 3rd International Civil Engineering and Architecture Congress, Türkiye, 12 Ekim 2023

  • Yayın Türü: Bildiri / Tam Metin Bildiri
  • Doi Numarası: 10.31462/icearc.2023.sme561
  • Basıldığı Ülke: Türkiye
  • Karadeniz Teknik Üniversitesi Adresli: Evet

Özet

Purpose: Reinforced concrete (RC) buildings are significant engineering structures that must withstand various static and dynamic loads, as well as environmental effects, over their operational lifespan. These structures are vulnerable to damage or complete loss of their load-bearing capacity due to two primary dynamic loads: earthquakes and fires. This study aimed to explore the combined effects of fire and earthquakes that could potentially lead to structural damage. In this study, the structural behavior of a RC plane frame model with a history of fire exposure and subjected to varying levels of earthquake effects was investigated experimentally.

Study design/methodology/approach: This study primarily encompasses the construction of the experimental model, subjecting the model to fire testing and conducting a series of shake table tests on the fire-damaged model. Throughout the experimental process, following each event that could lead to alterations in the construction of the model and its structural behavior, Experimental Modal Analysis (EMA) measurements were conducted to determine the dynamic

characteristics of the model. The assessments were made based on the changes observed in the dynamic characteristics of the model.

Findings: After the fire, the natural frequency values of the first three modes of the structure significantly decreased. The decrease in frequency values continued cumulatively with increasing earthquake damage to the fire-damaged experimental specimen placed on the shaking table. Ultimately, reductions of 54.48%, 64.73%, and 76.69% were observed in the 1st, 2nd, and 3rd modes of the model, respectively.

Originality/value: Significant changes in the dynamic characteristics of a structure indicate potential structural damage. The EMA method yields highly effective results for the prediction and detection of damage that may occur in the structure. The study outcomes emphasize the importance of interventions aimed at preparing a structure, exhibiting weaknesses due to fire-related factors to be resilient against seismic events.