Assessment of Residual Strength Based on Estimated Temperature of Post-Heated RC Columns

• Main Authors: Muhammad Yaqub, Imran A. Bukhari, Usman Ghani
• Format: Article
• Language: English
• Published: Mehran University of Engineering and Technology 2013-01-01
• Series: Mehran University Research Journal of Engineering and Technology
• Subjects: Columns; Residual Strength; Temperature; Finite Element Model.
• Online Access: http://publications.muet.edu.pk/research_papers/pdf/pdf735.pdf
• ISSN: 0254-7821; 2413-7219

The experience shows that fire-damaged concrete structures both technically and economically can be reinstated after fire due to high fire resistance and high residual strength. The residual strength of fire-damaged concrete structural member depends on the peak temperature reached during fire, fire duration and the distribution of temperature within the structural member. The assessment of the residual strength of post-heated concrete structural members in a professional way is a prime factor to take a decision about the reinstatement or demolition of fire-damaged structure. This paper provides an easy and efficient approach to predict the residual strength of reinforced concrete columns based on the estimated temperature which may have occurred within the concrete cross-section during a fire. A finite element model was developed to evaluate the distribution of temperature within the cross-section of the reinforced concrete columns. Twelve reinforced concrete square columns were heated experimentally up to 500°C at 150°C/hour. A comparison of the experimental temperature values of the tested columns was made with the model results. A good agreement was found between the experimental and the finite model results. Based on the temperature distribution obtained from the finite element model, the residual strength of concrete and reinforcement could be evaluated by using the relationships for concrete, steel and temperature proposed by various researchers.