An approach for calculating the failure loads of unprotected concrete filled steel columns exposed to fire

Abstract

/npsi/ctrl?lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?lang=fr Access and use of this website and the material on it are subject to the Terms and Conditions set forth at http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur.Structural Engineering and Mechanics, 7, 2, pp. 127-145, 1999-02-01 An approach for calculating the failure loads of unprotected concrete filled steel columns exposed to fire Wang, Y. C.; Kodur, V. K. R. Structural Engineering and Mechanics, 7, (2), February, pp. 127-145, February 01, 1999 The material in this document is covered by the provisions of the Copyright Act, by Canadian laws, policies, regulations and international agreements. Such provisions serve to identify the information source and, in specific instances, to prohibit reproduction of materials without written permission. For more information visit http://laws.justice.gc.ca/en/showtdm/cs/C-42Les renseignements dans ce document sont protégés par la Loi sur le droit d'auteur, par les lois, les politiques et les règlements du Canada et des accords internationaux. Ces dispositions permettent d'identifier la source de l'information et, dans certains cas, d'interdire la copie de documents sans permission écrite. Pour obtenir de plus amples renseignements : http://lois.justice.gc.ca/fr/showtdm/cs/C-42 .... . .&2Srructural Engineering and Mechanic.., Vol. 7. No.2 (1999) [127][128][129][130][131][132][133][134][135][136][137][138][139][140][141][142][143][144][145] An approach for calculating the failure loads of unprotected concrete filled steel columns exposed to fire Abstract. This paper deals with the development of an approach for evaluating the squash load and rigidity of unprotected concrete filled steel columns at elevated temperatures. The current approach of evaluating these properties is reviewe!!. It is shown that with a non-uniform temperature distribution, over the composite cross-section, the calculations for the squash load and rigidity are tedious in the current method. A simplified approach is proposed to evaluate the temperature distribution, squash load, and rigidity of composite columns. This approach is based on the model in Eurocode 4 and can conveniently be used to calculate the resistance to axial compression of a concrete filled steel column for any fire resistance time. The accuraey of the proposed approach is assessed by comparing the predicted strengths against the results of fire tests on concrete filled circular and square steel columns. The applicability of the proposed approach to a design situation is iIlustra:ed thrOUgh a numerical example.

Study of recycled concrete–filled steel tubular columns on the compressive capacity and fire resistance

“…In summary, at a certain temperature, the axial compression load N src (T) of the HRCFST section with plasticity concern, as expressed in equation (35), and stability coefficient u src (T ), as expressed in equation (37), for the axial compression load of the HRCFST column with stability concern can be verified by the present experimental value and other experiments. 13,[31][32][33][34][35][36] The ratio results of calculated value to experimental value for verification are tabulated in Table 4.…”

Fire resistance of concrete-filled steel tube columns with preload. Part II: Numerical and analytical investigation

“…The mean value of the ratios of the numerical results to the results from the formulas and the variance are, respectively, 0.975 and 0.012. The maximum error is within 7.5%, illustrating that the predictions from the formulas are sufficiently accurate compared to the predictions from other researchers [30,31] .…”

A unified method for calculating the fire resistance of concrete-filled steel tube with fire protection under combined loading

“…for CFST columns was proved to be unsafe, which led to a recent inclusion of an amendment stating that the relative slenderness of the columns should be less than 0.5 for the use of the method. Under this context, a number of practical design formulas were proposed by many researchers, e.g., [24] , who conducted parametric analysis through experiments and numerical calculations, and proposed formulas for calculating fire resistance of solid circular and square CFST columns using regression analysis; Wang and Kodur (1999) [25] developed an approach for evaluating squash load and rigidity of solid CFST columns at elevated temperature based on Euro Code 4 [1] . Wang (2000) [26] presented a method for circular CFST columns with and without fire protection, which required point interpolation to obtain the squash load and rigidity of a column.…”

“…In the authors' previous research [33] , a simplified method was proposed to calculate average temperature of the steel and the concrete in a CFST column, as shown in Eq. 24and (25). In this section, new research on calculating average temperature of unprotected CFST columns is presented.…”