Study on Fire Performance of Reinforced Concrete Structures

Abstract

Assessment, repair, and rehabilitation of fire-damaged structures have become a prominent area of interest due to the increasing incidents of major fires in buildings. This specialized field requires expertise in various areas, including concrete technology, material science and testing, structural engineering, and repair materials and techniques. Ongoing research and development efforts are being undertaken in this field and related disciplines to address these challenges. Real-life experiences with fire-damaged buildings provide valuable insights, offering a comprehensive understanding of restoration strategies and the use of different non-destructive techniques for assessment, as well as specifications and execution of repair methods. In one specific experiment, the impact of fire on reinforcement steel bars was studied. Six samples each were heated to different temperatures of 100°C, 300°C, 600°C, and 900°C. After heating, the samples were rapidly cooled using both quenching in water and normal air cooling. The mechanical properties of the bars were examined utilizing a general testing machine (UTM), and a tiny investigation of grain size and grain structure was directed utilizing a checking electron magnifying instrument (SEM).The results indicated that the majority of fire-damaged reinforced concrete structures can be repaired successfully. However, it was observed that temperatures above 900°C significantly reduced ductility when the bars were rapidly cooled by quenching. In contrast, cooling the bars in normal atmospheric conditions showed less impact on ductility. It was also noted that heating the reinforcement bars can alter their mechanical properties without affecting the chemical composition. Overall, the findings from this research shed light on the importance of proper assessment and repair techniques for fire-damaged structures, providing valuable insights for the field of fire safety and building restoration.