The Influence of Spalling on the Fire Resistance of RC Structures

2011 ◽  
Vol 255-260 ◽  
pp. 519-523 ◽  
Author(s):  
Xin Meng Yu ◽  
Xiao Xiong Zha ◽  
Zhao Hui Huang
Keyword(s):  
Fire Resistance ◽  
Elevated Temperatures ◽  
Analysis Procedure ◽  
Structural Members ◽  
Thermal And Mechanical Properties ◽  
Structural Behaviour ◽  
Rc Structures ◽  
Parametric Studies ◽  
Rc Slabs ◽  
In Fire

A great many of experiments has shown that reinforced concrete (RC) structures suffered from spalling in fire. However, at present there are still no convincing spalling predicting models available due to the inhomogeneous nature and complicated thermo-hydro-mechanical interactions in concrete at elevated temperatures. In order to evaluate the fire resistance of RC structures which are subjected to concrete spalling, a thermal analysis procedure is developed which considers the effects of spalling on the growth of temperature in RC members. The predicted temperatures are then used to model the structural behaviour. The spalled portion of concrete is modelled as "void", which has no thermal and mechanical properties. A series of parametric studies carried out on RC structural members with different boundary conditions shows that the influence of spalling on fire resistance is very significant apart from the RC slabs subject to higher laterally restraint.

Study on the Data-Bases for Fire Engineering Design of Structural Steels Members

2012 ◽  
Vol 628 ◽  
pp. 156-160
Author(s):  
In Kyu Kwon ◽  
Hyung Jun Kim ◽  
Heung Youl Kim ◽  
Bum Yean Cho ◽  
Kyung Suk Cho
Keyword(s):  
Bearing Capacity ◽  
Fire Resistance ◽  
Engineering Method ◽  
Fire Tests ◽  
Structural Members ◽  
Data Bases ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
In Fire ◽  
Resistance Performance

Structural steel has been used since the early 1970’s in Korea as primary structural members such as columns, beams, and trusses. The materials have much higher strength such as fast construction, high load bearing capacity, high construction quality but those have a fatal weakness as well. Load-bearing capacity is going down when the structural members are contained in fire condition. Therefore, to protect the structural members made of steels from the heat energy the fire resistance performance required. Generally, the fire resistance performance have evaluated from the exact fire tests in fire furnaces. But the evaluation method takes much more time and higher expenses so, the engineering method requires. The engineering method not only adopts a science but also an engineering experience. In this paper, to make various data-bases for evaluation of structural members such as columns(H-section, RHS), beams, loaded fire tests were conducted and derived not only each limiting temperature but also fire resistance respectively.

Behaviour of steel frames under fire conditions

1999 ◽  
Vol 26 (2) ◽  
pp. 156-167 ◽  
Author(s):  
D I Nwosu ◽  
VKR Kodur
Keyword(s):  
Fire Resistance ◽  
Steel Frames ◽  
Load Ratio ◽  
Steel Structures ◽  
Point Of View ◽  
Frame Structures ◽  
Structural Behaviour ◽  
Analysis And Design ◽  
In Fire ◽  
Fire Conditions

A state-of-the-art review of the behaviour of steel frame structures in fire is presented. Results from different studies indicate that the behaviour of a complete structure is different from that of a single structural member under fire conditions from the point of view of fire resistance. Earlier studies also show that analysis and design of steel structures against fire based on their overall behaviour could lead to a reduction or the elimination of applied fire protection to certain structural members. The effects of continuity, restraint conditions, and load ratio on the fire resistance of frame structures are discussed. The beneficial aspects derived from considering overall structural rather than single-member behaviour in fire are illustrated through the analysis on two one-bay, one-storey, unprotected steel portal frames, a column, and a beam. Also comparison is made between the performance of a beam with different end restraints in fire. Results from the analyses indicate that the fire resistance of a member is increased when it is considered as part of a structure compared with when it is considered as a single member.Key words: steel, frames, fire resistance, buckling, loads, overall structural behaviour.

scholarly journals Properties of Concrete at Elevated Temperatures

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Venkatesh Kodur
Keyword(s):  
Fire Resistance ◽  
Elevated Temperatures ◽  
Mechanical Deformation ◽  
Structural Members ◽  
Fire Response ◽  
Key Characteristics ◽  
Deformation Properties ◽  
Different Types ◽  
Resistance Performance

Fire response of concrete structural members is dependent on the thermal, mechanical, and deformation properties of concrete. These properties vary significantly with temperature and also depend on the composition and characteristics of concrete batch mix as well as heating rate and other environmental conditions. In this chapter, the key characteristics of concrete are outlined. The various properties that influence fire resistance performance, together with the role of these properties on fire resistance, are discussed. The variation of thermal, mechanical, deformation, and spalling properties with temperature for different types of concrete are presented.

Experimental study of two-way post-tensioned flat slabs in fire

2018 ◽  
Vol 9 (3) ◽  
pp. 237-251 ◽  
Author(s):  
Li Zhang ◽  
Ya Wei ◽  
Francis Tat Kwong Au ◽  
Jing Li
Keyword(s):  
Design Methodology ◽  
Structural Integrity ◽  
Elevated Temperatures ◽  
Testing Temperature ◽  
Structural Behaviour ◽  
Content Type ◽  
Flat Slabs ◽  
Temperature Distributions ◽  
In Fire ◽  
Post Tensioned

Purpose This study aims to investigate the influence of tendon layout, pre-stressing force, bond condition and concrete spalling on the structural behaviour of two-way post-tensioned flat slabs at elevated temperatures. Design/methodology/approach Fire tests of four scale specimens of two-way post-tensioned concrete flat slabs were performed and analysed. Three of them were provided with bonded tendons, while the other was unbonded for comparison. The fabrication of specimens, phenomena observed during testing, temperature distributions, deflections and occurrence of concrete spalling were examined. Findings Different degrees of concrete spalling observed at the soffit had significant effects on the temperature distribution and stress redistribution. This was the major reason for the progressive concrete spalling observed, resulting in loss of structural integrity and stiffness. Originality/value The structural behaviour of two-way post-tensioned concrete flat slabs at elevated temperatures is less understood compared to their one-way counterparts. Therefore, the present study has focused on the structural behaviour of two-way post-tensioned concrete flat slabs with bonded tendons in fire, a field in which relatively little information on experimental work can be found.

scholarly journals Thermal and mechanical properties of steel-fibre-reinforced concrete at elevated temperatures

1996 ◽  
Vol 23 (2) ◽  
pp. 511-517 ◽  
Author(s):  
T. T. Lie ◽  
V. K. R. Kodur
Keyword(s):  
Mechanical Properties ◽  
Thermal Properties ◽  
Reinforced Concrete ◽  
Fire Resistance ◽  
Elevated Temperatures ◽  
Steel Fibre ◽  
Fibre Reinforced Concrete ◽  
Thermal And Mechanical Properties ◽  
Steel Fibre Reinforced Concrete ◽  
Deformation Properties

For use in fire resistance calculations, the relevant thermal and mechanical properties of steel-fibre-reinforced concrete at elevated temperatures were determined. These properties included the thermal conductivity, specific heat, thermal expansion, and mass loss, as well as the strength and deformation properties of steel-fibre-reinforced siliceous and carbonate aggregate concretes. The thermal properties are presented in equations that express the values of these properties as a function of temperature in the temperature range between 0 °C and 1000 °C. The mechanical properties are given in the form of stress–strain relationships for the concretes at elevated temperatures. The results indicate that the steel fibres have little influence on the thermal properties of the concretes. The influence on the mechanical properties, however, is relatively greater than the influence on the thermal properties and is expected to be beneficial to the fire resistance of structural elements constructed of fibre-reinforced concrete. Key words: steel fibre, reinforced concrete, thermal properties, mechanical properties, fire resistance.

scholarly journals Stability of Stainless Steel I-Section Beam-Columns at Elevated Temperatures

2020 ◽  
pp. 2150037
Author(s):  
Merih Kucukler ◽  
Zhe Xing ◽  
Leroy Gardner
Keyword(s):  
Stainless Steel ◽  
Elevated Temperatures ◽  
Steel Beam ◽  
Design Rules ◽  
Beam Columns ◽  
Parametric Studies ◽  
In Fire ◽  
Improved Accuracy ◽  
Rules Set ◽  
Fire Design

With the growing use of stainless steel in the construction and offshore industries, there is an increasing interest and need to study the performance of stainless structures at elevated temperatures. The behavior and design of stainless steel I-section beam-columns in fire is investigated in this paper, addressing a scarcity of previous research on this topic. Finite element (FE) models of stainless steel beam-columns, able to replicate their response at elevated temperatures, are created and validated; the validated models are then used to perform parametric studies to generate extensive benchmark structural performance data. The design rules set out in the European structural steel fire design standard EN 1993-1-2 are assessed and shown to provide rather inaccurate and often unsafe ultimate strength predictions for stainless steel I-section beam-columns in fire. New fire design rules for stainless steel beam-columns are put forward. It is shown that the new proposals are able to offer improved accuracy and design efficiency relative to the EN 1993-1-2 beam-column design rules. The reliability of the proposed design rules is also verified on the basis of the fire design reliability criteria set out by Kruppa [Eurocodes–Fire parts: Proposal for a methodology to check the accuracy of assessment methods, CEN TC 250, Horizontal Group Fire, Document no: 99/130 (1999)], thereby demonstrating the suitability of the proposed design rules for inclusion in the upcoming revised version of EN 1993-1-2.

REVIEW ON COLUMN FIRE RESISTANCE DESIGN FOR CONCRETE FILLED STEEL TUBE

2018 ◽  
Vol 80 (6) ◽  
Author(s):  
Bishir Kado ◽  
Shahrin Mohammad ◽  
Yeong Huei Lee ◽  
Poi Ngian Shek ◽  
Mariyana Aida Ab. Kadir ◽  
...  
Keyword(s):  
Fire Resistance ◽  
Elevated Temperatures ◽  
Steel Tube ◽  
Tube Steel ◽  
Outer Diameter ◽  
Structural Behaviour ◽  
Concrete Filled Steel Tube ◽  
Standard Fire ◽  
Foamed Concrete ◽  
Cfst Columns

The use of concrete filled steel tube (CFST) columns offers an alternative for providing the required fire resistance and load bearing capacity, making its use in medium and high rise structures are highly popular. This paper aims to review the previous studies on CFST column under fire. The standards or codes of practice used in fire resistance designs have been highlighted. The design of the CFST column is summarised with previous investigations on experiments and numerical modelling at ambient temperature and elevated temperature. Different conclusions were drawn depending on the material’s properties, considered parameters and the method used for the investigations. Outer diameter or width of the steel tube, steel tube thickness, concrete grade, column length, and eccentricity of loadings are among the parameters that affects the structural behaviour of CFST columns under fire. Several numerical analyses software were adequately used for simulating the behaviour of CFST columns at elevated temperatures, and validated using experimental results. Furthermore, the advantages of using the fire resistance design approaches on CFST columns filled with lightweight foamed concrete is highlighted. In conclusion, there is the need for more studies on standard fire tests of CFST column filled with light weight foamed concrete which is not covered in the current design guide.

scholarly journals The structural fire design of concrete structures with externally bonded reinforcement and fire protection system

2013 ◽  
Vol 12 (1) ◽  
pp. 179-186
Author(s):  
Piotr Turkowski
Keyword(s):  
Fire Protection ◽  
Test Procedure ◽  
Structural Members ◽  
Rc Structures ◽  
Structural Fire ◽  
Building Research Institute ◽  
Protection Systems ◽  
Externally Bonded ◽  
In Fire ◽  
Fire Design

This work describes the structural fire design process of RC structures with externally bonded reinforcement. First part is based on the calculation method given in EN 1992-1-2 and addresses the question whether the fire protection of externally bonded reinforcement is necessary in every situation? The second part shows what such fire protection should look like and how it should be designed. Moreover, a test procedure for determining the effectiveness of applied fire protection systems to concrete structural members reinforced with FRP, used in Fire Testing Laboratory of Building Research Institute (ITB) is presented.

scholarly journals BEHAVIOUR OF ALUMINIUM STRUCTURES IN FIRE, A review

2016 ◽  
Author(s):  
Davor Skejić ◽  
Ivan Ćurković ◽  
Marija Jelčić Rukavina
Keyword(s):  
Carbon Steel ◽  
Structural Material ◽  
Fire Resistance ◽  
Steel Structures ◽  
Future Research ◽  
Surface Emissivity ◽  
Structural Behaviour ◽  
Structural Fire ◽  
In Fire ◽  
Fire Design

The interest in the application of aluminium as a structural material has been greatly increased in recent years. However, behaviour of aluminium structures when exposed to fire is still relatively unresearched. Due to low melting temperature of the alloy, aluminium structures have low fire resistance, but aluminium is reflective and has surface emissivity which is more than two times lower compared to carbon steel. The Eurocode facing this issue (EN 1999-1-2) is based mainly on the Eurocode for structural fire design of steel structures (EN 1993-1-2) and therefore is not fully suitable for the application on aluminium structures. Here, an overview of the structural behaviour of aluminium structures exposed to fire is given through the comparison with steel structures. As a conclusion, priorities for a future research are highlighted, which should provide a base for the next generation of modern codes for structural fire design of aluminium structures.

scholarly journals Effect of air-gap on response of fabricated slim floor beams in fire

2019 ◽  
Vol 10 (2) ◽  
pp. 155-174 ◽  
Author(s):  
Naveed Alam ◽  
Ali Nadjai ◽  
Chrysanthos Maraveas ◽  
Konstantinos Tsarvdaridis ◽  
Charles Kahanji
Keyword(s):  
Thermal Behaviour ◽  
Design Methodology ◽  
Elevated Temperatures ◽  
Structural Response ◽  
Structural Members ◽  
Considerable Influence ◽  
Content Type ◽  
Modelling Method ◽  
Perform Sensitivity Analysis ◽  
In Fire

PurposeThe purpose of this study is to investigate the effect of the airgap on thermal behaviour and structural response of fabricated slim floor beams (FSFBs) in fire.Design/methodology/approachA detailed analytical model is established and validated by replicating the response of FSFBs. The validated finite element modelling method is then used to perform sensitivity analysis. First, the influence of the airgap presence is analysed, and later, the effect of the airgap size on thermal behaviour and structural response of FSFBs at elevated temperatures is investigated.FindingsResults from the study demonstrate that the presence of the airgap has a considerable influence on their thermal behaviour and structural response of FSFBs. The size of the airgap, however, has no significant influence on their thermal and structural response in fire.Originality/valueNo investigations, experimental or analytical, are available in literature addressing the effect of airgap on the structural response of FSFBs in fire. The presence of airgap is helpful and beneficial; hence, the findings of this research can be used to develop designs for structural members with airgap as an efficient and inexpensive way to improve their response in fire.

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