Stahlbeton-Durchlaufkonstruktionen unter Feuerangriff bei Variierung von Stahlart und -güte der Biegezugbewehrung im Stützbereich: Bericht

Kordina, Karl; Wesche, Julius

doi:10.24355/dbbs.084-201401101434-0

Cited by 2 publications

(15 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Unless strongly over-dimensioned (as some slabs shown in Figure 4), the top reinforcement at the intermediate support starts yielding in the first 10-20 min of fire exposure, as observed by Kordina and Wesche 4 and evidenced from all figures in this paper. In this early stage of fire exposure, the rotation capacity mainly depends on the ductility of reinforcing steel, just as at ambient temperature.…”

Section: Ductilitysupporting

confidence: 75%

“…On the other hand, the design provisions for one-way continuous slabs rely on a considerable amount of extrapolation and engineering judgment, given the rather scarce experimental evidence. In fact, only three of nine slabs tested by Kordina and Wesche 4 reached the fire resistance time expected based on the tabulated design data given in EN 1992-1-2. Therefore, the study presented in this paper mainly focuses on the behavior of statically indeterminate one-way slabs.…”

Section: Introductionmentioning

confidence: 75%

“…The parametric study investigates the behavior of statically indeterminate members exposed to fire using the configurations of the experimental studies carried out at TU Braunschweig in the 1970s 3,4 as its starting point. The specimens are denominated according to the names of the respective researchers, For this example, KW-9 for Slab 9 from Kordina and Wesche 4 or W-1 for Beam 1 from Wesche. 3 Adopting the configurations of the experimental studies allows a direct comparison as long as only material properties (e.g.…”

Section: Parametric Studymentioning

confidence: 99%

“…The curves representing the measured experimental results are plotted as dashed gray lines in all relevant figures. Note that the modeled reinforcement strains represent the bending moment directly at the intermediate support (modeled as line support), while the strains measured in the experiments 3,4 were determined over a length of 100 mm at the intermediate support with actual supports, implying lower strains than modeled.…”

Section: • Tension Stiffeningmentioning

confidence: 99%

“…campaigns carried out at TU Braunschweig in the 70s and 80s to study the behavior of (continuous) reinforced concrete members under fire conditions, [2][3][4][5][6] in addition to the observation and evaluation of real fires. Over the past 40 years, further experimental studies on restrained beams under fire conditions were carried out, [7][8][9][10] all showing the superior performance of continuous beams unless insufficient shear reinforcement is provided to account for load redistributions.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Assessment of parameters influencing the behavior of statically indeterminate reinforced concrete slabs and beams under fire conditions

Bischof

Morf

Kaufmann

2022

Structural Concrete

View full text Add to dashboard Cite

This paper investigates the effect of material properties, boundary conditions, and related modeling and design uncertainties on the fire behavior of statically indeterminate reinforced concrete beams and slabs by means of a parametric study based on a comprehensive model. This model uses material properties specified by EN 1992‐1‐2, complemented by considerations concerning the biaxial compressive strength of concrete, strain hardening and limitations of the ultimate strain of reinforcement, as well as tension stiffening. The parametric study identifies and explains the most influential parameters governing the fire behavior of statically indeterminate reinforced concrete beams and slabs. The implementation and generalization of these parameters are evaluated and compared to current design rules in EN 1992‐1‐2 derived from the evaluation of experimental testing and real fire cases. Overall, the detailing rules given in EN 1992‐1‐2 are found to be reasonably safe, and they can be easily used for practical applications. Furthermore, the results of the study indicate that model predictions for the studied statically indeterminate systems are subject to considerable uncertainty because (i) information on the used material is possibly incomplete and (ii) the models given in design codes do not (or only insufficiently) cover all relevant aspects of the thermo‐mechanical behavior. Specifically, the concrete aggregate type with its corresponding thermal expansion, the strain hardening properties of the reinforcement and tension stiffening with its detrimental effect on the ductility of the tension chord may affect the rating across several standard fire resistance times of statically indeterminate reinforced concrete members subjected to bending.

show abstract

Section: Ductilitysupporting

confidence: 75%

Section: Introductionmentioning

confidence: 75%

Section: Parametric Studymentioning

confidence: 99%

Section: • Tension Stiffeningmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Assessment of parameters influencing the behavior of statically indeterminate reinforced concrete slabs and beams under fire conditions

Bischof

Morf

Kaufmann

2022

Structural Concrete

View full text Add to dashboard Cite

show abstract

Modeling statically indeterminate reinforced concrete slabs and beams under fire conditions

Bischof

Morf

Bamonte

et al. 2022

Structural Concrete

View full text Add to dashboard Cite

EN 1992‐1‐2 generally limits the redistribution of bending moments from the intermediate supports to the span for continuous reinforced concrete slabs and beams in fire conditions to 15%. While higher redistributions are allowed if sufficient rotation capacity is provided, EN 1992‐1‐2 does not indicate how to assess the rotation capacity. However, plastic hinges caused by the rotation demand under fire conditions are highly relevant when predicting the global response and structural safety of a structure (partially) exposed to fire. Rotation capacity is specifically necessary at support regions subjected to negative bending and fire, where concrete in compression undergoes thermal degradation while the tension chord remains close to ambient temperature. This article presents a comprehensive model for the behavior of statically indeterminate members in fire conditions, enabling to estimate whether sufficient rotation capacity is provided. Material properties specified by EN 1992‐1‐2 are applied combined with complementary considerations concerning (i) the biaxial compressive strength of concrete, (ii) strain hardening and limitations of the ultimate strain of reinforcement, as well as (iii) tension stiffening. Tension stiffening detrimentally influences the ductility of the tension chord, limiting the rotation capacity. When comparing predictions obtained by the model to experimental results given in the literature, the correlation is good for the investigated one‐way continuous slabs and beams. However, considerable uncertainty exists regarding the type of concrete aggregate used. Moreover, uncertainties concerning the behavior of concrete under compression and fire conditions are highly relevant for modeling the region of supports with rotational restraint.

show abstract

Stahlbeton-Durchlaufkonstruktionen unter Feuerangriff bei Variierung von Stahlart und -güte der Biegezugbewehrung im Stützbereich: Bericht

Cited by 2 publications

References 0 publications

Assessment of parameters influencing the behavior of statically indeterminate reinforced concrete slabs and beams under fire conditions

Assessment of parameters influencing the behavior of statically indeterminate reinforced concrete slabs and beams under fire conditions

Modeling statically indeterminate reinforced concrete slabs and beams under fire conditions

Contact Info

Product

Resources

About