Fig. 1. Confinement of concrete by lateral reinforcement
Fig. 2. Behavior of column with lateral reinforcement
Fig. 3. Geometry of test specimens(unit : mm)
Fig. 4. Temperature Cycle
Fig. 5. The furnace and test setup
Fig. 6. Compression test
Fig. 7. Temperatures of specimen at 800℃
Fig. 8. Normalized peak stress versus temperature(ST5 type)
Fig. 9. Normalized peak stress versus temperature(ST9 type)
Fig. 10. Comparison of residual stress between ST5 and ST9 type specimen
Fig. 11. Comparison of strains between ST5 and ST9 type specimen
Fig. 12. Elastic modulus of high temperatures compared with E of 20℃(ST 5 TYPE)
Fig. 13. Elastic modulus of high temperatures compared with E of20℃(ST 9 TYPE)
Fig. 14. Elastic modulus due to heating faces(ST5)
Fig. 15. Elastic modulus due to heating faces(ST9)
Fig. 16. Load-displacement curves depending on different heating faces with ST5 type specimen
Fig. 17. Load-displacement curves depending on different heating faces with ST9 type specimen
Table 1. The concrete mixture proportions
Table 2. Test results on specimens
Table 3. Percent residual peak stress after thermal cycle
Table 4. Difference of residual stresses between ST9 and ST5 type(%)
Table 5. Strains by difference of heating faces and stirrups at 10MPa of stress
Table 6. Remaining elastic modulus resulting from a thermal cycle
Table 7. Variation in elastic modulus due to heating faces
References
- Arioz, O. (2007). Effect of elevated temperatures on properties of concrete, Fire Safety Journal, 42(8), 516-522. https://doi.org/10.1016/j.firesaf.2007.01.003
- Choi, K.H., Lee, J.W. (2011). Effect of high temperature on mechanical properties of confined concrete with lateral reinforcement, Journal of the Korean Institute of Structural Maintanence and Inspection, 16(1), 213-220 [in Korean].
- Dos Santos, J.R., Branco, F.A., Brito, J. (2002). Assessment of concrete structures subjected to fire, Magazine of Concrete Research, 54(3), 203-208. https://doi.org/10.1680/macr.2002.54.3.203
- Kim, S.S. (2018). Structural Design of Reinforced Concrete, Munundang, 307-312 [in Korean].
- Khoury, G.A. (1992). Compressive strength of concrete at high temperatures: a reassessment, Magazine of Concrete Research, 44(161), 291-309. https://doi.org/10.1680/macr.1992.44.161.291
- Wu, B., Su, X., Li, H., Yuan, J. (2002). Effect of high temperature on residual mechanical properties of confined and unconfined high-strength concrete, ACI Material Journal, 99(4), 399-407.