SLIDE 1 International Conference on Urban Habitat Constructions under Catastrophic Events COST Action C26 Naples, Italy, 2010
Fire Resistance of Self-Compacting Concrete Beam-Column Sub-Assemblage
- I. K. Fang , C. C. Lee, L. W. Chou, P. S. Chiu,
- T. W. Liu, J. M. Yeh
Department of Civil Engineering National Cheng Kung University Taiwan
SLIDE 2
Objectives
(1)Fire resistance of beam-column sub- assemblage designed based on seismic provisions (2)Possible differences between ordinary and self-compacting concrete components under fire (3)Establish the data base for future fire- performance based design
SLIDE 3
Model residential building
SLIDE 4
Deformation of model building at service load stage
SLIDE 5
Specimen installed inside the furnace before heating
SLIDE 6
Reinforcement details and locations of thermocouples
SLIDE 7
Fabrication of specimens
SLIDE 8
SLIDE 9
SLIDE 10
SLIDE 11
Beam support away from joint
SLIDE 12
Instrumentation of beam deflection measurement
SLIDE 13
Variations of furnace temperature
SLIDE 14
Temperature gradient inside beam
SLIDE 15
Variations of temperature of longitudinal reinforcement in beam
SLIDE 16
Variations of temperature of stirrup in beam
SLIDE 17
Deformed shape of beam during heating (Specimen NC5)
SLIDE 18
Deformed shape of beam during heating (Specimen SCC5)
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Deformed shape of beam during heating (Specimen SCC4)
SLIDE 20
Spalling occurred along the bottom edge of beam during early stage of heating
SLIDE 21
Spalling of specimen SCC4 after heating test
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Spalling of specimen SCC5 after heating test
SLIDE 23
Spalling of specimen NC5 after heating test
SLIDE 24 Spalling of column (NC5, SCC5, SCC4) NC5n
NC5 SCC5 SCC4
SLIDE 25
Load procedure
SLIDE 26
Specimen SCC4 (Top of beam near joint)
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Horizontal displacements of beam and column during heating (Specimen SCC5)
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Rate of deflection at P2 during heating
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Total beam load vs. deflection at P2 (Residual strength test)
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Flexural failure near P2 (Residual strength test, Specimen NC5)
SLIDE 31
Shear failure at P1 (Residual strength test, Specimen SCC5)
SLIDE 32 Conclusions
1) The specimens, designed according to the ACI 318 seismic provisions, behaved satisfactorily under ISO834 standard fire exposure for three hours. 2) Most of the concrete spalling occurred along the bottom edge of beams and corner of lower column during the early twenty five minutes of
- heating. Relatively more spalling was observed
at bottom of beam in normal concrete specimen NC5.
SLIDE 33
Conclusions
3) The maximum temperatures recorded at several locations in longitudinal reinforcements of beam and column reached 580℃, which exceeds the limit 550℃ at single point specified in Taiwanese Standard CNS 12514.
SLIDE 34 Conclusions
4) Relatively more vertical displacements in beam occurred in the first thirty minutes
- f heating, and then the increase of
vertical displacement decreased during the thirty to sixty minutes due to the low temperature rise in beam.
SLIDE 35
Conclusions
5) The normal and self-compacting concrete specimens behaved quite closely in their load- displacement relationships at load point in residual strength test.
SLIDE 36
Conclusions
6) Two specimens failed in ductile flexural mode and one specimen failed in unfavorable diagonal shear after exhibiting significant yield behavior in beams. The decrease of shear strength in beam cross section has to be checked carefully after fire hazard.
