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.

scholarly journals Punching Shear Behavior of Reinforced Concrete Slabs under Fire using Finite Elements

2020 ◽  
Vol 26 (5) ◽  
pp. 106-127
Author(s):  
Athraa H. Gharbi ◽  
Akram S. Mahmoud
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Shear Failure ◽  
Punching Shear ◽  
Concrete Slabs ◽  
Mechanical And Thermal Properties ◽  
Element Analysis ◽  
Reinforced Concrete Slabs ◽  
Fire Condition ◽  
Increasing Temperature

The main aim of this paper is studied the punching shear and behavior of reinforced concrete slabs exposed to fires, the possibility of punching shear failure occurred as a result of the fires and their inability to withstand the loads. Simulation by finite element analysis is made to predict the type of failure, distribution temperature through the thickness of the slabs, deformation and punching strength. Nonlinear finite element transient thermal-structural analysis at fire conditions are analyzed by ANSYS package. The validity of the modeling is performed for the mechanical and thermal properties of materials from earlier works from literature to decrease the uncertainties in data used in the analysis. A parametric study was adopted in this study,  it has many factors such as the ratios of length to thickness, fire temperature, time exposed to fire, concrete compressive strength, area exposed to fires and type of support. It can be concluded from this research the significant factors that affect the punching shear strength. However, the increasing ratio of length to thickness may be lead to increasing the deflection more than 123% at fire condition. Also, the increasing temperature leads to increasing the deflection about 40% at fire condition.

scholarly journals Finite Element Analysis of Reinforced Concrete Slabs with Spherical Voids

2013 ◽  
Vol 6 (4) ◽  
pp. 15-37
Author(s):  
Amer M. Ibrahim ◽  
Nazar K. Ali ◽  
Wissam D. Salman
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Compressive Strain ◽  
Strain Curve ◽  
Point Load ◽  
Concrete Slabs ◽  
Finite Element Models ◽  
Element Analysis ◽  
Reinforced Concrete Slabs ◽  
Spherical Voids

This paper presents a numerical analysis using ANSYS finite element program to simulate the reinforced concrete slabs with spherical voids when subjected to five point load. Six slabs with length 1.0m, width 1.0m, height (0.1m and 0.125m) and simply supported were modeled. Nonlinear materials behavior, as it relates to steel reinforcing bars and plain concrete, and linear behavior for steel plate is simulated using appropriate constitutive models. The results showed that the general behavior of the finite element models represented by the load-deflection curves at mid-span, ultimate load, load-maximum concrete compressive strain curve, and crack patterns show good agreement with the test data from the experimental test. The finite element models represented by this work can be used to carry out parametric study for the BubbleDeck slab specimens

scholarly journals Elaboration of testing technique of flat slabs on punching shear strength using finite element modeling

2018 ◽  
Vol 196 ◽  
pp. 02048
Author(s):  
Valery Filatov ◽  
Zulfat Galyautdinov ◽  
Alexander Suvorov
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Cross Section ◽  
Strain State ◽  
Concrete Slabs ◽  
Finite Element Models ◽  
Bending Moments ◽  
Stress Strain ◽  
Stress Strain State ◽  
Reinforced Concrete Slabs

The results of researches on finite-element models of stress-strain state of flat reinforced concrete slabs of beamless frame under punching by columns of square and rectangular cross-section are presented. The purpose of the study was to develop a technique for testing samples plates for punching in the presence of bending moments in a column. The results of the study of deflections of reinforced concrete slabs, the distribution of bending moments in the punching zone of the plate under various loading schemes are presented. Variable parameter was the ratio of the sides of the column cross-section. Comparative analysis of studies results on finite element models has made it possible to choose the optimal variant of applying the load to the test samples, depending on the aspect ratio of rectangular section of column. Results of the conducted research will allow simulating the stress-strain state in the punching zone of natural reinforced concrete slabs of monolithic beamless frame during the test of samples.

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

scholarly journals Designing reinforced concrete slabs under fire condition

2018 ◽  
Vol 196 ◽  
pp. 02036
Author(s):  
Michał Maciąg ◽  
Szymon Spodzieja
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slabs ◽  
Reinforced Concrete Slabs ◽  
Fire Condition

In this article the capacity of reinforced concrete slabs of thickness larger than 15 cm was calculated with Isotherm 500 Method. For designed elements were analysed the support and span zone. There have been proposed tables for designers, on which basis it is possible to design slab of demanded fire capacity.

scholarly journals Modelling of reinforced concrete slabs in fire

2018 ◽  
Vol 100 ◽  
pp. 171-185 ◽  
Author(s):  
Yong Wang ◽  
Guanglin Yuan ◽  
Zhaohui Huang ◽  
Junli Lyu ◽  
Qingtao Li ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slabs ◽  
Reinforced Concrete Slabs ◽  
In Fire
Sign in / Sign up

Export Citation Format

Share Document