Fire Resistance of Reinforced Concrete Columns: a Parametric Study

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. For the publisher's version, please access the DOI link below./ Pour consulter la version de l'éditeur, utilisez le lien DOI ci-dessous.http://dx.doi.org/10.1177/104239158900100402Journal of Fire Protection Engineering, 1, 4, pp. 121-129, 1989 Fire resistance of reinforced concrete columns: a parametric study Lie, T. T. SUMMARYExperimental and theoretical studies were carried out to develop general methods for the prediction of the fire resistance of reinforced concrete columns. In these studies, which were carried out jointly between the National Research Council of Canada and the Portland Cement Association, 41 columns were tested. The parameters studied included bad level, amount of steel reinforcement, effective length of column, concrete strength, moisture Content, area and shape of cross section, aggregate type, axial restraint of thermal expansion and load eccentricity. The experimentally discovered effects of these parameters are discussed.

Heat transfer and structural response modelling of FRP confined rectangular concrete columns in fire

“…Hence, the model under predicted the failure time by at least 25% in comparison to the failure time observed by Lie and Woollerton [29] during the fire test. Furthermore, note that the heat transfer portion of the computational model predicted higher temperatures within the column in comparison to the temperatures observed during the fire test [29], which may have also resulted in the conservative of the current model. The current model uses a more precise method to determine the second order lateral deflections of the column in fire based an assumed effective length of 2000 mm obtained from previous research studies (e.g.…”

“…Preloaded concrete may be 25% stronger than an unloaded concrete at elevated temperatures provided that the initial compressive stress from the preload is about 25 to 30% of the initial room temperature compressive strength [13]. Hence, the model under predicted the failure time by at least 25% in comparison to the failure time observed by Lie and Woollerton [29] during the fire test. Furthermore, note that the heat transfer portion of the computational model predicted higher temperatures within the column in comparison to the temperatures observed during the fire test [29], which may have also resulted in the conservative of the current model.…”

“…Table 1 and Fig. 7 present selected predicted and observed axial load carrying capacity of the unwrapped square reinforced concrete columns in fire for tests reported by Lie and Woollerton [29]. Table 2 shows that the model is generally conservative, and under predicts the failure time by between 27% and 46%.…”

“…The computational model has been validated by comparing its predictions against experimental results presented in the literature [27][28][29][30][31] on both concentrically and eccentrically loaded unwrapped reinforced concrete and FRP strengthened reinforced concrete square columns under both ambient and fire conditions.…”

“…The computational model was also validated by comparison against several experiments presented by Lie and Woollerton [29] on unwrapped square reinforced concrete columns in fire. These tests were on 305 mm square columns which were 3810 mm long and reinforced internally with four 25 mm diameter deformed steel bars in the longitudinal direction and with 10 mm diameter ties at 406 mm spacing with a clear cover of 48 mm to the longitudinal reinforcement.…”