scholarly journals Evaluation of Fire Resistance Performance and Temperature Distribution by Depth of Reinforced Concrete Slab Subjected to Fire

2021 ◽  
Vol 21 (1) ◽  
pp. 179-187
Author(s):  
Jangsik Yoon ◽  
Byongjeong Choi

The yield or ultimate strength of a structure can be deteriorated by fire, leading to structural collapse. Temperature estimation has been studied in concrete members to identify the internal temperature distribution of reinforced concrete members at high temperatures. While foreign standards such as ACI 216 and Eurocode exist, no domestic standards have not been established for fire-resistant designs (temperature of components, strength reduction factor). This study discussed the temperature estimation and comparison of slab members using the methods of Hertz, Wickstrőm, Kodur, Eurocode, and ACI 216.1 and analyzed the differences from actual experiments by comparing reinforced concrete experiments, foreign standards, and existing studies.

2011 ◽  
Vol 71-78 ◽  
pp. 712-716
Author(s):  
An Duan ◽  
Wei Liang Jin

The purpose of this research is to investigate the influence of the freeze-thaw cycles on the flexural behavior of reinforced concrete members. The variation of the concrete stress-strain relationship due to frozen-thawed deterioration was considered. The temperature distribution was calculated based on the heat conduction theory, and the damaged region affected by freeze-thaw cycles was determined. By using Reponse-2000 program, the flexural behaviour of a reinforced concrete slab was analyzed and predicted. The analytical results show that with increase of number of freeze-thaw cycles, the yield moment, the ultimate moment and the curvature ductility decreased, while the relative depth of neutral axis and the midspan deflection increased.


2021 ◽  
Vol 2 (7 (110)) ◽  
pp. 23-30
Author(s):  
Vitalii Kovalchuk ◽  
Artur Onyshchenko ◽  
Olexander Fedorenko ◽  
Mykola Habrel ◽  
Bogdan Parneta ◽  
...  

This paper reports the full-scale experimental measurements of temperature distribution over the surfaces of bridges' steel-concrete beams under the influence of positive and negative ambient temperatures. It has been established that the temperature is distributed unevenly along the vertical direction of a bridge's steel-concrete beam. It was found that the metal beam accepted higher temperature values. The maximum registered temperature difference between a metal beam and a reinforced concrete slab at positive ambient temperatures was +9.0 °C, and the minimum temperature difference was −2.1 °C. The mathematical models for calculating a temperature field and a thermally strained state of bridges' steel-concrete beams under the influence of variable climatic temperature changes in the environment have been improved, taking into consideration the uneven temperature distribution across a bridge's reinforced concrete beam. The possibility has been established to consider a one-dimensional problem or to apply the three-dimensional estimated problem schemes as the estimation schemes for determining the thermo-elastic state of reinforced concrete bridges. The temperature field and the stressed state of bridges' reinforced concrete beams were determined. It was found that the maximum stresses arise at the place where a metal beam meets a reinforced concrete slab. These stresses amount to 73.4 MPa at positive ambient temperatures, and 69.3 MPa at negative ambient temperatures. The amount of stresses is up to 35 % of the permissible stress values. The overall stressed-strained state of a bridge's reinforced concrete beams should be assessed at the joint action of temperature-induced climatic influences and loads from moving vehicles


2007 ◽  
Vol 13 (4) ◽  
pp. 295-302 ◽  
Author(s):  
Darius Bačinskas ◽  
Gintaris Kaklauskas ◽  
Viktor Gribniak ◽  
Edgaras Geda

There are many buildings and civil engineering works under construction which are at risk of fire. The fire resistance analysis of reinforced concrete structures constitutes an important part in their design. However, the analysis of the behaviour of load‐bearing members under high temperature conditions is very complicated. Various factors that influence the behaviour of the members need to be taken into account. Analytical and computation methods have been developed in the field of reinforced concrete building exposed to high temperature or accidental fire. Unfortunately, such models are computationally too demanding and their application are limited even for a simply supported reinforced concrete members (beams, plates etc). In this paper, an attempt has been made to extend application of the Flexural model to stress and strain analysis of flexural reinforced concrete members subjected to high temperature. Constitutive models and key material parameters describing thermo‐mechanical behaviour of concrete and reinforcement are discussed. A powerful calculation technique based on layered approach is briefly described. A numerical example of application of present method for calculating of stresses, strains and curvatures of reinforced concrete slab is presented.


Author(s):  
Ralph Alan Dusseau

The results of a study funded by the U.S. Geological Survey as part of the National Earthquake Hazards Reduction Program are presented. The first objective of this study was the development of a database for all 211 highway bridges along I-55 in the New Madrid region of southeastern Missouri. Profiles for five key dimension parameters (which are stored in the database) were developed, and the results for concrete highway bridges are presented. The second objective was to perform field ambient vibration analyses on 25 typical highway bridge spans along the I-55 corridor to determine the fundamental vertical and lateral frequencies of the bridge spans measured. These 25 spans included six reinforced concrete slab spans and two reinforced concrete box-girder spans. The third objective was to use these bridge frequency results in conjunction with the dimension parameters stored in the database to develop empirical formulas for estimating bridge fundamental natural frequencies. These formulas were applied to all 211 Interstate highway bridges in southeastern Missouri. Profiles for both fundamental vertical and lateral frequencies were then developed, and the results for concrete highway bridges are presented.


1985 ◽  
Vol 50 ◽  
Author(s):  
A. Atkinson ◽  
D. J. Goult ◽  
J. A. Hearne

AbstractA preliminary assessment of the long-term durability of concrete in a repository sited in clay is presented. The assessment is based on recorded experience of concrete structures and both field and laboratory studies. It is also supported by results of the examination of a concrete sample which had been buried in clay for 43 years.The enoineering lifetime of a 1 m thick reinforced concrete slab, with one face in contact with clay, and the way in which pH in the repository as a whole is likely to vary with time have both been estimated from available data. The estimates indicate that engineering lifetimes of about 103 years are expected (providing that sulphate resisting cement is used) and that pH is likely to remain above 10.5 for about 106 years.


2014 ◽  
Vol 606 ◽  
pp. 229-232 ◽  
Author(s):  
Petr Tej ◽  
Vítězslav Vacek ◽  
Jiří Kolísko ◽  
Jindřich Čech

The paper focuses on a computer nonlinear analysis of the formation and development of cracks in a concrete slab exposed to a uniform continuous load on the lower surface. The analysis is based on an actual example of the formation and development of cracks in a basement slab exposed to ground water buoyancy.


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