Behaviour of steel reinforced concrete beams considering overall fire stages
| Autor: | Yong-Qian Zheng, Zheng Zhang |
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| Rok vydání: | 2015 |
| Předmět: | |
| Zdroj: | Magazine of Concrete Research. 67:294-307 |
| ISSN: | 1751-763X 0024-9831 |
| DOI: | 10.1680/macr.14.00275 |
| Popis: | Finite-element models (FEMs) for analysing the temperature field and mechanical performance of steel reinforced concrete (SRC) beams considering overall fire stages were established. This work also developed secondary programs for extracting the results of temperature and user subroutines for considering the influence of moisture at elevated temperature, steel creep at high temperature and the transformation of field variables. The results calculated using the FEMs were verified with related theoretical and experimental results. Based on the FEMs, the mechanical characteristics and parametric influences of SRC beams during the overall fire stage were analysed. Finally, practical calculation methods for the critical load level and the residual load-bearing capacity coefficient after fire were derived. The results show that, when the outer temperature drops, the temperature of the internal region keeps rising and the drop in temperature lags to some extent. The beam deflection increases further but gradually recovers after reaching the maximum deflection. For higher load levels, the time for deflection to reach the maximum and enter the recovery stage is later, and the extent of recovery is reduced. The critical load level and the residual load-bearing capacity coefficient after fire increase with a decrease in heating time or an increase in sectional dimension, section steel ratio or sectional depth-to-width ratio. The residual load-bearing capacity coefficient decreases with an increase in initial load level. |
| Databáze: | OpenAIRE |
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