scholarly journals Buckling of Radially Loaded Concrete Cylinders in Fire Condition

2019 ◽  
Vol 5 (6) ◽  
pp. 1214-1226
Author(s):  
Abdelraouf Tawfik Kassem
Keyword(s):  
Parametric Study ◽  
Slenderness Ratio ◽  
Load Ratio ◽  
Structural Behaviour ◽  
Full Spectrum ◽  
Fire Condition ◽  
Concrete Cylinders ◽  
Buckling Stability ◽  
Fire Endurance ◽  
In Fire

Concrete cylinders are commonly used in water treatment and sewerage plants, in the form of wells or basins. They are mainly subjected to axial compression resulting from soil lateral pressure and aqueous hydrostatic pressure, in case of the presence of a groundwater table; that is why they are mostly designed in the form of a circular hollow section. Concrete cylinders face a complicated case of loading in fire condition, as a result of material degradation in addition to thermally induced stresses. This paper studies buckling stability of that case where, a concrete cylinder is subjected to an internal fire load in addition to superimposed structural loads from the surrounding environment. The main objective of the research is to study buckling stability of concrete cylinders through identifying various structural and thermal parameters, controlling that behaviour. Finite element modelling using "Ansys 18.1" has been chosen as an approach to deal with the research problem. Twenty-five solid elements models have been prepared to study both thermal and structural behaviour of concrete cylinders in fire condition. Cylinder thickness, slenderness ratio, load ratio, and groundwater presence have been adopted as main research parameters to identify their effect on well's fire buckling endurance, in accordance with ISO 834 standard fire curve. A parametric study has been designed to study fire endurance vulnerability to cylinder thickness ranging from 50 mm up to 800 mm; diameter to thickness ratio [D/t] ranging from "10" up to "160"; full spectrum of structural load ratios; in addition to the presence of a surrounding groundwater. Outputs of the parametric study have been introduced in the form of figures, which could be used as preliminary design aids to identify buckling fire endurance as function of load ratio for various spectrums of thickness and slenderness ratios. Moreover, critical thicknesses and load ratios have been revealed.

scholarly journals Deformations of R.C.Circular Slabs in Fire Condition

2018 ◽  
Vol 4 (4) ◽  
pp. 712 ◽  
Author(s):  
Abdelraouf Tawfik Kassem
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Slenderness Ratio ◽  
High Surface ◽  
High Surface Area ◽  
Concrete Slabs ◽  
Finite Element Models ◽  
Reinforced Concrete Slabs ◽  
Fire Condition ◽  
In Fire

Reinforced concrete slabs are elements in direct contact with superimposed loads, having high surface area and small thickness. Such a condition makes slabs highly vulnerable to fire conditions. Fire results in exaggerated deformations in reinforced concrete slabs, as a result of material deterioration and thermal induced stresses. The main objective of this paper is to deeply investigate how circular R.C. slabs, of different configurations, behave in fire condition. That objective has been achieved through finite element modelling. Thermal-structural finite element models have been prepared, using "Ansys". Finite element models used solid elements to model both thermal and structural slab behaviour. Structural loads had been applied, representing slab operational loads, then thermal loads were applied in accordance with ISO 843 fire curve. Outputs in the form of deflection profile and edge rotation have been extracted out of the models to present slab deformations. A parametric study has been conducted to figure out the significance of various parameters such as; slab depth, slenderness ratio, load ratio, and opening size; regarding slab deformations. It was found that deformational behaviour differs significantly for slabs of thickness equal or below 100 mm, than slabs of thickness equal or above 200 mm. On the other hand considerable changes in slabs behaviour take place after 30 minutes of fire exposure for slabs of thickness equals or below 100 mm, while such changes delay till 60 minutes for slabs of thickness equals or above 200 mm.

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.

Review of Fire Performance Experiment of Concrete-Filled Steel Tubular Columns

2014 ◽  
Vol 638-640 ◽  
pp. 1397-1401
Author(s):  
Kai Xiang ◽  
Guo Hui Wang ◽  
Yan Chong Pan
Keyword(s):  
Load Ratio ◽  
Experimental Results ◽  
Research Progress ◽  
Future Research ◽  
Fire Performance ◽  
Cross Sectional ◽  
Tubular Columns ◽  
Cross Sectional Dimension ◽  
Cfst Columns ◽  
In Fire

This paper presents a review of research progress in fire performance of concrete-filled steel tubular (CFST) columns. Experimental results of CFST columns in fire are reviewed with influence parameters, such as heights, cross-sectional dimension, section types, concrete types, concrete strengths, load ratio, load eccentricity, fire exposed sides and so on. Some conclusions of CFST columns under fire conditions are summarized. Deficiencies in the fire performance experiments of CFST columns are identified, which provide the focus for future research in the field.

Structural behaviour in fire compartment under different heating regimes — part 2: (slab mean temperatures)

2000 ◽  
Vol 35 (2) ◽  
pp. 117-130 ◽  
Author(s):  
A.M Sanad ◽  
S Lamont ◽  
A.S Usmani ◽  
J.M Rotter
Keyword(s):  
Structural Behaviour ◽  
In Fire

Structural behaviour of FRP reinforced concrete slabs in fire

2020 ◽  
Vol 221 ◽  
pp. 111058 ◽  
Author(s):  
Antonio Bilotta ◽  
Alberto Compagnone ◽  
Laura Esposito ◽  
Emidio Nigro
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slabs ◽  
Structural Behaviour ◽  
Reinforced Concrete Slabs ◽  
In Fire

Parametric Study of Beam to Column Extended Endplate Connection in Fire

2012 ◽  
Vol 594-597 ◽  
pp. 779-784
Author(s):  
Meng Wang
Keyword(s):  
Cross Section ◽  
Failure Modes ◽  
Numerical Study ◽  
Numerical Models ◽  
Great Influence ◽  
Load Ratio ◽  
Simulation Methodology ◽  
Study Results ◽  
Endplate Connection ◽  
In Fire

In this paper, numerical study results using ABAQUS are presents to demonstrate the failure modes and the behaviour of endplate connection with different parameters at elevated temperature. Numerical models and simulation methodology are first validated by the comparison to experimental data. Then the behaviour of beam and the failure modes endplate connection with different parameters- including beam span, beam load ratio, column cross section, endplate type- are studied. It can be concluded that all these parameters has a effects on the behaviour of the connection, while some parameters has a great influence on the survivability of the joint.

Structural fire performance of wood-steel-wood bolted connections with and without perpendicular-to-wood grain reinforcement

2019 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Adam Roman Petrycki ◽  
Osama (Sam) Salem
Keyword(s):  
Time To Failure ◽  
Bolted Connections ◽  
Content Type ◽  
Structural Fire ◽  
Fire Condition ◽  
Glued Laminated Timber ◽  
End Distance ◽  
Wood Grain ◽  
Mass Timber ◽  
In Fire

Purpose In fire condition, the time to failure of a timber connection is mainly reliant on the wood charring rate, the strength of the residual wood section, and the limiting temperature of the steel connectors involved in the connection. The purpose of this study is to experimentally investigate the effects of loaded bolt end distance, number of bolt rows, and the existence of perpendicular-to-wood grain reinforcement on the structural fire behavior of semi-rigid glued-laminated timber (glulam) beam-to-column connections that used steel bolts and concealed steel plate connectors. Design/methodology/approach In total, 16 beam-to-column connections, which were fabricated in wood-steel-wood bolted connection configurations, in eight large-scale sub-frame test assemblies were exposed to elevated temperatures that followed CAN/ULC-S101 standard time-temperature curve, while being subjected to monotonic loading. The beam-to-column connections of four of the eight test assemblies were reinforced perpendicular to the wood grain using self-tapping screws (STS). Fire tests were terminated upon achieving the failure criterion, which predominantly was dependent on the connection’s maximum allowed rotation. Findings Experimental results revealed that increasing the number of bolt rows from two to three, each of two bolts, increased the connection’s time to failure by a greater time increment than that achieved by increasing the bolt end distance from four- to five-times the bolt diameter. Also, the use of STS reinforcement increased the connection’s time to failure by greater time increments than those achieved by increasing the number of bolt rows or the bolt end distance. Originality/value The invaluable experimental data obtained from this study can be effectively used to provide insight and better understanding on how mass-timber glulam bolted connections can behave in fire condition. This can also help in further improving the existing design guidelines for mass-timber structures. Currently, beam-to-column wood connections are designed mainly as axially loaded connections with no guidelines available for determining the fire resistance of timber connections exerting any degree of moment-resisting capability.

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