REALISTIC MODELING OF COMPOSITE AND REINFORCED CONCRETE FLOOR SLABS UNDER EXTREME LOADING. II: VERIFICATION AND APPLICATION

This paper deals with the large displacement behavior of floor slab systems under extreme loading conditions. The analytical model, presented in the companion paper, is verified through comparisons against existing experimental results on both reinforced concrete and composite slabs, with flat or ribbed profiles. The new model incorporates a novel shell element and accounts for material and geometric nonlinearities under ambient as well as elevated temperatures. The verification studies examine the response of reinforced concrete slabs under unrestrained and restrained edge conditions. An assessment of the behavior of ribbed floor slabs is also undertaken, in addition to simulation of the structural response of a full-scale composite beam-slab floor system under a realistic compartment fire situation. The results show good correlation between the experimental findings and numerical predictions, and demonstrate the reliability and robustness of the proposed analytical model. Additionally, the studies and discussions presented in this investigation provide an insight into the key behavioral aspects of floor slabs under extreme conditions. In particular, the significance of compressive arching and tensile membrane actions, under various boundary conditions, is illustrated. Also, the importance of adopting a realistic representation of the composite slab geometry is highlighted. The proposed analytical model is of particular relevance to developments in performance-based structural fire design, where realistic assessment of the floor slab response is of paramount importance.

[1]  Yong Wang,et al.  The behaviour of steel frames subject to fire , 1995 .

[2]  Bassam A. Izzuddin,et al.  REALISTIC MODELING OF COMPOSITE AND REINFORCED CONCRETE FLOOR SLABS UNDER EXTREME LOADING. I: ANALYTICAL METHOD , 2004 .

[3]  Jef Robinson.  Fire -- A Technical Challenge and a Market Opportunity , 1998 .

[4]  A. Y. Elghazouli,et al.  Analytical assessment of the structural performance of composite floors subject to compartment fires , 2001 .

[5]  Knud Winstrup Johansen.  Yield-line theory , 1962 .

[6]  M. A O'Connor,et al.  Behaviour of a Multi-storey Steel Framed Building Subjected to Fire Attack , 1998 .

[7]  P. F Johnson.  International developments in fire engineering of steel structures , 1998 .

[8]  Bassam A. Izzuddin,et al.  Lessons from a full-scale fire test , 2002 .

[9]  A. Y. Elghazouli,et al.  Failure of lightly reinforced concrete members under fire. II: Parametric studies and design considerations , 2004 .

[10]  Denis Mitchell,et al.  Preventing Progressive Collapse of Slab Structures , 1984 .

[11]  B. A. Izzuddin.  Quartic formulation for elastic beam-columns subject to thermal effects , 1996 .

[12]  Nicholas S. Trahair,et al.  Computer design of cold-formed C- and Z-section purlins , 1998 .

[13]  Andrew H. Buchanan,et al.  Structural Design for Fire Safety , 2001 .

[14]  D. B. Moore,et al.  The tensile membrane action of unrestrained composite slabs simulated under fire conditions , 2000 .

[15]  A. Y. Elghazouli,et al.  Failure of Lightly Reinforced Concrete Members under Fire. I: Analytical Modeling , 2004 .

[16]  B. Izzuddin,et al.  Nonlinear dynamic analysis of framed structures , 1990 .

[17]  P. J. Dowling,et al.  An integrated adaptive environment for fire and explosion analysis of steel frames — Part I:: analytical models , 2000 .

[18]  D. C. Drucker,et al.  Plastic and Elastic Design of Slabs and Plates , 1963 .

[19]  John F. Brotchie,et al.  MEMBRANE ACTION IN SLABS , 1971 .

[20]  R Park,et al.  ULTIMATE STRENGTH OF RECTANGULAR CONCRETE SLABS UNDER SHORT-TERM UNIFORM LOADING WITH EDGES RESTRAINED AGAINST LATERAL MOVEMENT. , 1964 .

[21]  A. Y. Elghazouli,et al.  Response of idealised composite beam–slab systems under fire conditions , 2000 .

[22]  G. M. Newman.  Structural design for fire , 1991 .

[23]  A. Y. Elghazouli,et al.  Numerical modelling of the structural fire behaviour of composite buildings , 2000 .

[24]  Amr S. Elnashai,et al.  ADAPTIVE SPACE FRAME ANALYSIS. PART II: A DISTRIBUTED PLASTICITY APPROACH. , 1993 .