Reliability of Steel Columns Protected by Intumescent Coatings Subjected to Natural Fires

This thesis studied the effect of aging of intumescent coatings (ICs) on the reliability of protected steel columns in fire condition and developed a probabilistic approach to assess the service life of ICs applied on steel columns. In the study, Monte Carlo simulations were conducted to obtain the reliability index or failure probability of steel columns protected by ICs subjected to compartment fires.  The effect of aging of intumescent coatings on the failure probability of protected steel columns was investigated by using variable insulation property of intumescent coatings in the simulation. The test data on aging effect on insulation property of intumescent coatings from literature was used. Based on the reliability analysis, a probabilistic approach is given to determine the service life of intumescent coatings for steel columns. In that approach, the failure probability of the protected steel columns is compared with the target probability of the structural fire design. The approach can also be used for probabilistic analysis of steel columns protected by conventional inert fire protection materials.

Introduction.- Fire Modeling.- Steel Temperature in Natural Fires.- Thermal Properties of Intumescent Coatings in Fire.- Behavior of Steel Columns in Fire.- Reliability Analysis.- Service Life of Intumescent Coatings.- Conclusions and Further Work.

Honors:
2014 IAFSS Best Thesis Award “Excellence in Research” for years 2011-2014
2013 Excellent Doctor Degree Dissertation of Tongji University 2013
2011 Arup Research Prize; Outstanding Graduate Student of Tongji University
2010 Fluor Scholarship; Outstanding Student of Tongji University;
Best Paper Award from China Association for Engineering Construction Standardization
2002-04 Outstanding Student of Wuhan University (3 times)

Publication list:
[1] GB Lou, MC Zhu, M Li, C Zhang, GQ Li. Experimental research on slip-resistant bolted connects after fire.
Journal of Constructional Steel Research, 2015;104:1-8.
[2] C Zhang, GQ Li, YC Wang. Probabilistic analysis of steel columns protected by intumescent coatings to
natural fires. Structural Safety , 2014;50:16-26.
[3] C Zhang*, JL Gross, TP McAllister. Lateral torsional buckling of steel W-beams subjected to localized
fires. Journal of Constructional Steel Research, 2013; 88:330-8. (*Corresponding author)
[4] C Zhang*, GQ Li, A Usmani. Simulating the behavior of restrained steel beams to flame impingement from
localized-fires. Journal of Constructional Steel Research, 2013; 83:156-65.
[5] GQ Li, C Zhang. The Chinese performance-based code for fire-resistance of steel structures. International
Journal of High-Rise Buildings, 2013;2:123-130.
[6]C Zhang, GQ Li, RL Wang. Using adiabatic surface temperature for thermal calculation of steel members
exposed to localized fires. International Journal of Steel Structures, 2013;13:547-56.
[7] C Zhang*, GQ Li. Modified one zone model for fire resistance design of steel structures. Advanced Steel
Construction, 2013;9:284-99.
[8] C Zhang, GQ Li, YC Wang. Predictability of buckling temperature of axially loaded steel columns in fire.
Journal of Constructional Steel Research, 2012; 75:32-7.
[9] GQ Li, C Zhang*. Creep effecton buckling of axially restrained steel columns in real fires. Journal of
Constructional Steel Research, 2012; 71:182-88.
[10] GQ Li, C Zhang*. Simple approach for calculating maximum temperature of insulated steel members in
natural-fires. Journal of Constructional Steel Research, 2012; 71:104-10.
[11] GQ Li, C Zhang*, GB Lou, YC Wang, LL Wang. Assess the fire resistance of intumescent coatings by
equivalent constant thermal resistance. Fire Technology, 2012; 48:529-46.
[12] C Zhang*, GQ Li, YC Wang. Sensitivity study on using different formulas for calculating the temperatures
of insulated steel members in natural fires. Fire Technology, 2012; 48:343-66.
[13] C Zhang*, GQ Li. Fire dynamic simulation on thermal actions in localized fires in large enclosure.
Advanced Steel Construction. 2012; 8:124-36.
[14] C Zhang*, GQ Li. Thermal response of steel columns exposed to localized fires – numerical simulation
and comparison with experimental results. Journal of Structural Fire Engineering,2011;2:311-7.
[15] GQ Li, C Zhang*. Thermal response to fire of uniformly insulated steel members: background and
verification of the formulation recommended by Chinese code CECS200. Advanced Steel Construction. 2010;
6:788-802.
[16] C Zhang*, JL Gross, L Choe. Behavior of steel components subjected to localized fires. Proceedings of
the 8th International Conference on Structures in Fire (SiF14), Shanghai, China, 2004, pp.171-8. (Poster
presentation)
[17] C Zhang*, GQ Li, YC Wang. Effect of aging on reliability of steel columns protected by intumescent
coatings to natural fires. Proceedings of the 7th International Conference on Structures in Fire (SiF12), ETH
Zurich, Zurich, Switzerland, pp. 145-54. (Oral presentation)
[18] C Zhang*, SC Jiang, GQ Li. Performance based fire resistance design of CFT columns in a railway
station. Proceedings of the 6thInternational Conference on Structures in Fire (SiF10), East Lansing, USA, 2010,
pp. pp. 441-8. (Poster presentation)
[19] GQ Li, C Zhang*. Thermal response of steel columns exposed to localized fires - numerical simulation
and comparison with experimental results. Proceedings of the 6th International Conference on Structures in Fire
(SiF10), East Lansing, USA, 2010, pp. 35-42. (Oral Presentation)
[20] GQ Li, C Zhang. Special issues for fire-resistance of steel buildings. HKIE 4th Annual Symposium 2012.
(Invited keynote)
[21] GQ Li, C Zhang. Fire resistance design on steel structures for large enclosure in China. 3rd International
Symposium on Cold-formed Metal Structures. Hong Kong, 2010. (Invited keynote)
[22] C Zhang*, GQ Li, YZ Yin, MC Luo. Fire resistance design of large space grid structures by PBA - a case
study of the fire resistance design of the roof structure of Kunming International Airport. ICASS09, 2009. (Oral
Presentation)
[23] GQ Li, C Zhang. Fire resistance of restrained steel components. 4th International Conference on
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