Structural System Degradation due to High Temperature Arising from Fire

Jamshid Mohammadi*, Jiahong (Joanne) Zuo**
* Professor, Department of Civil, Architectural and Environmental Engineering, Illinois Institute of Technology, Chicago, Illinois.
** Structural Engineer, Aurora, Illinois.
Periodicity:December - February'2013
DOI : https://doi.org/10.26634/jste.1.4.2134

Abstract

Among major effects of high temperatures on structural materials include a dramatic change in thematerial behavior and a reduction in the load resistance capacity. In a structural system, the high temperatures from fire along with the changes occurredto the material properties and behavior may affect the system's integrity and capability to supportloads. As the fire persists in a building, structural components suffer a gradual degradation processthat may eventually lead to structural collapse. From the serviceability point of view, a building isconsidered a loss once fire spreads to a major portion of it regardless of whether structural collapseoccurs or not. However, the collapse prevention is especially important to the safety of fire fighterswho stay around or inside the building until the fire is completely contained. In this regard, animportant design consideration is how to treat the collapse issue in a design code. At the presenttime, fire protection coating remains as the only safeguard against fire in buildings. No specificguidelines exist to address design strategies to reduce the risk of collapse in buildings during fire.In an effort to clarify on design issues for buildings subject to high temperature arising from fire,this paper presents the results of an investigation into the behavior of structures subject to hightemperatures during fire. Floor systems made up of reinforced concrete slabs with or withoutintermediate beams were investigated under application of a loading that consisted of dead load andfire exposure. The effect of high temperature on material strength and behavior; creep and crackingin concrete; formation of localized failures; and structural degradation resulting from loss of stiffnesswere investigated using a nonlinear finite element analysis. The analysis simulated the loadingprocess and followed the step-by-step structural degradation of floor systems until a predeterminedcollapse criterion was reached. The results revealed a dramatic loss of structural stiffness after atemperature increase of about 400-500 ° C. The paper also describes the significance of fire loadsin structural analysis and design. Issues pertinent to design include: (1) prevention; and (2) designfor safe performance in a fire. These issues as related to a performance-based design code arereviewed and discussed.

Keywords

Fire Effects, High Temperature Effects, Material Behavior, Structural Degradation, Structural Stability

How to Cite this Article?

Mohammadi, J., and Zuo, J. (2013). Structural System Degradation due to High Temperature Arising from Fire. i-manager’s Journal on Structural Engineering, 1(4), 1-12. https://doi.org/10.26634/jste.1.4.2134

References

[1]. ABAQUS (1995), ABAQUS user's manual, Version 5.3, Rabbitt, Karlson and Sorenson, Inc.,Pawtucket, R.I.
[2]. ACI (1989), Guide for Determining the Fire Endurance of Concrete Elements, ACI 261R, American Concrete Institute, Detroit, Michigan.
[3]. ASTM (1989) Standard test method for fire tests of building construction and materials, ASTME119-89, American Society for Testing and Materials, Philadelphia, Pennsylvania.
[4]. Bangash, M.Y.H. (1989), Concrete structures: numerical modeling and applications, Elsevier Applied Sciences, London and New York.
[5]. Barnett, J.R. (1991), "New design approach for steel structures exposed to fire," Journal of Fire Protection Engineering, Vol. 3, No. 1, p. 1-8.
[6]. Barnett, J.R. (1995) Structures subjected to accidental fire, in Proceedings of the 1995 Structural Lecture Series, American Society of Civil Engineers, Illinois Section, 203 North Wabash, Chicago, Illinois, USA.
[7]. Branson, D.E. and Christiason, M.L. (1970) Time dependent properties related to design strength and elastic properties, creep and shrinkage, in Designing for effects of creep, shrinkage, temperature in concrete structures, ACI Publication SP-27, American Concrete Institute, Detroit, Michigan, USA.
[8]. CRSI (1980), Reinforced Concrete Fire Resistance, 1st Edition, Engineering Practice Committee, Concrete Reinforcing Steel Institute, Chicago, Illinois, USA.
[9]. Lin, T.D. and Abrams, M.S. (1983). Simulation of realistic thermal restraint during fire test of floor and roofs, in Fire safety of concrete structures, ACI Publication SP-80, American Concrete Institute, Detroit, Michigan, USA.
[10]. Zienliewicz, O.C. and Watson, M. (1966), "Some creep effects in stress analysis with particular references to concrete pressure vessels," Nuclear Engineering & Design, Vol. 2, No.4.
[11]. Zuo, J. and Moharnmadi, J. (1996) Time-dependent degradation of structural systems during fire, Structural Engineering Series, Report# IIT-CAE-96-01, Department of Civil and Architectural Engineering, Illinois Institute of Technology, Chicago, Illinois, USA.
If you have access to this article please login to view the article or kindly login to purchase the article

Purchase Instant Access

Single Article

North Americas,UK,
Middle East,Europe
India Rest of world
USD EUR INR USD-ROW
Online 15 15

Options for accessing this content:
  • If you would like institutional access to this content, please recommend the title to your librarian.
    Library Recommendation Form
  • If you already have i-manager's user account: Login above and proceed to purchase the article.
  • New Users: Please register, then proceed to purchase the article.