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.

scholarly journals THE RELATIONSHIP BETWEEN COMPRESSIVE STRENGTH AND DENSITY OF POLYSTYRENE LIGHTWEIGHT CONCRETE WITH MIX PROPORTIONS

2021 ◽  
pp. 1-7
Author(s):  
Faisal K. Abdulhussein ◽  
Qais Frayyeh ◽  
Marwan Al-Shaikhli ◽  
Zahraa F. Jawad ◽  
Mohammed Salman5
Keyword(s):  
Fire Resistance ◽  
Absorption Rate ◽  
Building Materials ◽  
Elevated Temperatures ◽  
Lightweight Concrete ◽  
Short Circuit ◽  
Different Types ◽  
Aerated Concrete ◽  
Resistance Performance ◽  
The Relationship

Autoclaved aerated concrete (Called Thermostone in Iraq) is one of the popular building materials that are used in various purposes in construction industries. It is factory-made material that can be moulded into blocks which can be used in framework buildings. However, these buildings are under the risk of fire since it has different cusses such as arson and electrical short circuit. It is important to find ways to improve counter such phenomenon. Therefore the objective of this paper is investigating the fire resistance performance of Thermostone with and without plastering. Five different samples were used for the test, four of them were covered with different types of plastering. Three tests were employed for this study: Compressive, absorption, and density test. For all tests, the samples were exposed to elevated temperatures from 250 °C to 900 °C. It was shown that plastered samples have demonstrated a higher fire resistance and lower absorption rate than non-plastered ones.

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.

Comparison Study of Structural Stabilities for H-Section Columns Built with Ordinary Grade Strength Structural Steels According to Boundary Conditions and Lengths at High Temperature

2014 ◽  
Vol 937 ◽  
pp. 424-427
Author(s):  
In Kyu Kwon
Keyword(s):  
Boundary Condition ◽  
High Temperature ◽  
Boundary Conditions ◽  
Fire Resistance ◽  
Structural Steels ◽  
Structural Members ◽  
Steel Buildings ◽  
Standard Fire ◽  
Fire Curve ◽  
Resistance Performance

Fire resistance performance of structural members has been evaluated from each singular section and standard fire curve since the beginning of fire tests. However, the need of the exact fire resistance of H-section columns applied in the steel buildings has increased. The main reason for this is there is a difference between the conditions being conducted during the fire test and that from real situation. In this paper, the structural stability of H-section column made of an ordinary strength grade structural steels, SS 400, SM 400, and SM 490 at high temperature were evaluated and compared with boundary conditions and column’s length. This was done in order to suggest a new guideline for the application of fire protective materials in steel column in which the boundary conditions and column lengths are different from that tested with hinge to hinge and 3500 mm. The findings from this study showed hinge to hinge boundary condition was more conservative. And fire resistance performance of longer columns in the case of hinge to fixed and fixed to fixed boundary condition than from 3500 mm and hinge to hinge boundary condition can sustain at high temperature without adding fire protective materials.

Fire Resistance Evaluation of Reinforced Concrete Columns Using Axial Load Ratio and Slenderness Ratio

2014 ◽  
Vol 905 ◽  
pp. 268-272
Author(s):  
In Hwan Yeo ◽  
Bum Yean Cho ◽  
Jae Hong An ◽  
Byung Youl Min
Keyword(s):  
Fire Resistance ◽  
Axial Load ◽  
Slenderness Ratio ◽  
Load Ratio ◽  
Cost Effective ◽  
Concrete Columns ◽  
Accurate Estimation ◽  
Structural Members ◽  
Standard Fire ◽  
Resistance Performance

Since the column members in buildings deal with both vertical and horizontal loads, appropriated amount of load should be estimated in order to evaluate the fire resistance performance of the columns under loaded condition. However, according to the ISO 834, the international standard for the evaluation of structural members, the fire resistance performance evaluation of column members is only based on the displacement and displacement rate under loaded condition in a standard fire. The purpose of this study is to suggest appropriate axial load ratios for the evaluation of fire resistance performance. The test conducted in this study produced appropriate axial load ratios for different slenderness ratios. They are expected to contribute to more accurate estimation of fire resistance performance and more efficient and cost-effective structural design.

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.

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.

The role of bark type in relative tolerance to fire of three central Victorian Eucalypts

1968 ◽  
Vol 16 (3) ◽  
pp. 491 ◽  
Author(s):  
AM Gill ◽  
DH Ashton
Keyword(s):  
Fire Resistance ◽  
Fire Intensity ◽  
Bark Thickness ◽  
Relative Tolerance ◽  
Different Types ◽  
Heat Penetration ◽  
Fuel Accumulation ◽  
Extent Of Damage

A laboratory approach to the study of fire resistance in trees is described and the method applied to three central Victorian eucalypts which possess different types of bark. For each species, bark thickness increases with the girth of the trunk or older branches. The fibrous bark of E. obliqua is thicker than the subfibrous bark of E. radiata, and this in turn is thicker than the decorticating bark of E. cypellocarpa for the same girth of trunk or branch. The rate of heat penetration to the cambium, however, is greatest in E. obliqua and least in E. cypellocarpa. This apparent anomaly is due to the greater inflammability of the fibrous bark. It is suggested that the fire tolerance of a species should be evaluated against fuel accumulation and the fire intensity of the site, as well as the extent of damage to various parts of the tree and the ability of these parts to recover.

scholarly journals Case Study on Prediction of Temperature in Compartment Considering Fire Conditions in Buildings

2021 ◽  
Vol 21 (4) ◽  
pp. 61-68
Author(s):  
Gyuhwan Cho ◽  
Jaekwon Ahn
Keyword(s):  
Case Studies ◽  
Fire Resistance ◽  
Structural Member ◽  
Structural Members ◽  
Simulation Results ◽  
Resistance Performance ◽  
Fire Conditions ◽  
Room Corner Test

Current fire resistance standards for major structural members of buildings require uniform fire resistance performance (in hours). However, buildings may be vulnerable to various local-fire conditions, depending on the industry or business, so it is necessary to examine their differences through simulations. In this study, the existing room corner test (KSF ISO 9705) and simulation results were compared to verify the reliability of the simulations. Next, the similarity of the results was identified. Simulations of actual buildings were performed based on local-fire conditions, and it was verified that the temperature varies by location. Based on the results, it is necessary to focus on performance-based fire resistance design rather than the specification-based design, which requires uniform fire resistance performance in hours. Simulation case studies should be conducted to reflect the diversity of the fire and structural member conditions.

scholarly journals PREDICTION OF RESIDUAL STRENGTH OF COMPOSITE COLUMNS USING FEM ANALYSIS

2016 ◽  
Author(s):  
Sun-Hee Kim ◽  
Kyong-Soo Yom ◽  
Sung-Mo Choi
Keyword(s):  
Temperature Distribution ◽  
Fire Resistance ◽  
Residual Strength ◽  
Load Capacity ◽  
Fem Analysis ◽  
Economic Losses ◽  
Structural Members ◽  
Steel Columns ◽  
Structural Deterioration ◽  
Resistance Performance

Fires in buildings cause not only economic losses but also many casualties. A prolonged fire involves the possibility of the damage to structural members, which calls for the repair or reinforcement of the building. Since it is critical to decide whether structural members need reinforcement, the technique to determine the degree of the damage to structural members caused by a fire should be established.  CFT columns are superior to generic steel columns in terms of fire resistance performance thanks to the thermal storage effect of the concrete inside the columns.  Studies have suggested how to reinforce the concrete to further improve the structural strength and fire resistance performance of CFT columns. When CFT columns of a building are damaged by a fire, it is required to determine preciously how serious the structural deterioration of the members is.  The purpose of this study is to evaluate the residual strength of CFT columns damaged by a fire by evaluating the temperature distribution inside the columns and determining the degree of deterioration in the load capacity of concrete and steel in relation to temperature distribution.

Potential Uses of Vinegar as a Medicine and Related in vivo Mechanisms

2016 ◽  
Vol 86 (3-4) ◽  
pp. 127-151 ◽  
Author(s):  
Zeshan Ali ◽  
Zhenbin Wang ◽  
Rai Muhammad Amir ◽  
Shoaib Younas ◽  
Asif Wali ◽  
...  
Keyword(s):  
Chemical Structure ◽  
Review Paper ◽  
Heart Diseases ◽  
Folk Medicine ◽  
Active Role ◽  
Current Review ◽  
Different Types ◽  
Positive Effect

While the use of vinegar to fi ght against infections and other crucial conditions dates back to Hippocrates, recent research has found that vinegar consumption has a positive effect on biomarkers for diabetes, cancer, and heart diseases. Different types of vinegar have been used in the world during different time periods. Vinegar is produced by a fermentation process. Foods with a high content of carbohydrates are a good source of vinegar. Review of the results of different studies performed on vinegar components reveals that the daily use of these components has a healthy impact on the physiological and chemical structure of the human body. During the era of Hippocrates, people used vinegar as a medicine to treat wounds, which means that vinegar is one of the ancient foods used as folk medicine. The purpose of the current review paper is to provide a detailed summary of the outcome of previous studies emphasizing the role of vinegar in treatment of different diseases both in acute and chronic conditions, its in vivo mechanism and the active role of different bacteria.

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