Numerical Modeling of Mechanical Properties for Reinforced Concrete Beams Exposed to Fire

• Main Authors: Jui-Hsiang Hsu, 徐 瑞 祥
• Other Authors: Cherng-ShingLin
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/88438064107548254949

博士 === 元智大學 === 機械工程學系 === 94 === Population densities are typically high in urban areas, including in cities in Taiwan. More than 90% of the buildings in Taiwan use reinforced concrete (RC) structures and on average 10,000 fires occur annually. Following fire damage, whether the RC structures are sufficiently safe must be determined to protect human life and property. The fire safety of any RC structure depends strongly on its resistance to fire, which in turn depends on the combustibility and fire resistance of its main structural elements, beams and columns. No two fires are the same so modeling must be employed to study the behavior of RC beams exposed to fire. The fact that different parts of the cross-section of a beam are exposed to different temperatures during a building fire makes the analysis in such beam structures a nontrivial problem. In this study, our thermal analysis employs the finite different method to model the various temperature distributions of reinforced concrete beam after sustaining high temperature. The modified version of the ACI (American Concrete Institute) Code then is used to include the effects of temperature on the reinforced steel and concrete materials, and the residual abilities of reinforced concrete beams are accordingly calculated. The analytical results, including the residual ultimate bending moment, residual shear strength and residual elastic modulus, are compared to experimental results in the literature with actual full-scale RC beam fire attack, and consistency between them has proved our method to be an accurate mathematical modeling. Extensive simulations are carried out to calculate a new equivalent beam which has the same residual abilities like the beam exposed to fire.