Fire can have a serious impact on the strength and stability of reinforced concrete structures, making it an important area of study in structural engineering and safety design. A recent research publication by Ir. Ts. Dr. Tengku Anita Raja Hussin from the Faculty of Engineering, Built Environment and Information Technology explores how reinforced concrete performs when exposed to fire under combined thermal and mechanical loading.
The study focuses on reinforced concrete beams and columns subjected to ISO 834 fire conditions under sustained load. By combining experimental testing with numerical simulation, the research provides deeper insight into how high temperatures affect structural behaviour, material degradation, and overall load bearing performance.
The findings reveal that concrete properties remain relatively stable up to around 300°C, but begin to deteriorate significantly at higher temperatures due to moisture loss and the decomposition of hydrates. At around 700°C, the residual compressive strength of concrete falls to below 30% of its original ambient value. The study also identified the progressive formation of tensile cracks and spalling in heated regions, along with a critical reduction in flexural stiffness and reinforcement strength above 500°C.
Using ABAQUS with temperature dependent material models and realistic boundary conditions, the validated numerical model showed strong agreement with laboratory test results. This demonstrates the reliability of the proposed modelling framework for performance based fire design and future parametric studies involving reinforced concrete structures under thermo mechanical coupling.
The research highlights the importance of considering both temperature dependent material degradation and sustained loading in fire resistance assessments. Its findings contribute valuable knowledge towards the development of safer, more resilient structural systems and more informed fire design practices in the built environment.