scholarly journals BUCKLING LOAD OF RC COLUMNS EXPOSED TO ISO FIRE LOAD, The influence of the cross-sectional dimensions

2016 ◽  
Author(s):  
Urška Bajc ◽  
Miran Saje ◽  
Tomaž Hozjan ◽  
Igor Planinc ◽  
Sebastjan Bratina
Keyword(s):  
Reinforced Concrete ◽  
Elevated Temperatures ◽  
Load Capacity ◽  
Buckling Load ◽  
Concrete Column ◽  
Mechanical And Thermal Properties ◽  
Fire Load ◽  
Reinforced Concrete Column ◽  
Cross Sectional ◽  
The Cross

The influence of the cross-sectional dimensions on the buckling load capacity of reinforced concrete column exposed to ISO fire load is presented. The fire analysis is divided in two separate phases. In the first phase, the calculation of the temperatures over the cross-section of the concrete column is performed. Here more advanced hygro-thermal analysis is executed to take into account the influence of moisture on the distribution of the temperatures. In the second step of the fire analysis, the mechanical analysis is performed. The mechanical and thermal properties of concrete and reinforcement at elevated temperatures are used in accordance with EN 1992-1-2 (2004). For two different cross-sections, the parametric study has been performed. The critical buckling time and critical buckling capacity as a function of a load and slenderness of reinforced concrete column have been determined.

A self-locking steel bearing connection for circular reinforced concrete columns

2019 ◽  
Vol 22 (12) ◽  
pp. 2605-2619
Author(s):  
Denghu Jing ◽  
Shuangyin Cao ◽  
Theofanis Krevaikas ◽  
Jun Bian
Keyword(s):  
Reinforced Concrete ◽  
Cross Sections ◽  
Axial Loading ◽  
High Strength ◽  
Axial Stiffness ◽  
Concrete Column ◽  
Reinforced Concrete Column ◽  
Cross Sectional ◽  
Locking Mechanism ◽  
The Cross

This article proposes a new connection between a steel bearing and a reinforced concrete column, which is mainly used for provisionally providing jack support in existing reinforced concrete structures. In this suggested connection joint, the steel bearing consisted of two or four symmetrical components assembled by high-strength bolts, which surrounds the reinforced concrete column by a tapered tube and balances the vertical load via the friction force between the tapered tube and concrete, that is, through a self-locking mechanism. The proposed connection joint can be assembled easily at a construction site and can also be disassembled and reused many times. To demonstrate the feasibility of this type of connection joint, a simple test was conducted to illustrate the concept, that is, a total of four medium-scale steel bearing–reinforced concrete column connections with circular cross sections were fabricated and tested under axial loading. The test results showed that the steel bearing–reinforced concrete column connection based on self-locking mechanism exhibited good working performance. Furthermore, a simplified formula to predict the axial stiffness of the connection joint was presented. From the tests and the proposed formula, the most important factors that influence the axial stiffness of this type of connection joint on the premise of an elastic working state are the slope of the tapered tube, the height of the steel bearing, the thickness of the tapered tube, the cross section of the reinforced concrete column, the cross-sectional area of all the connecting bolts, the proportion of the number of top bolts, the area of the top ring plate, and the effective contact area ratio.

Inelastic buckling load of a locally weakened reinforced concrete column

2012 ◽  
Vol 34 ◽  
pp. 278-288 ◽  
Author(s):  
N. Krauberger ◽  
S. Bratina ◽  
M. Saje ◽  
S. Schnabl ◽  
I. Planinc
Keyword(s):  
Reinforced Concrete ◽  
Buckling Load ◽  
Concrete Column ◽  
Reinforced Concrete Column ◽  
Inelastic Buckling

Evaluation for RC Column Confined Partially with Externally FRP Wrapping Sheet Using Nonlinear FE Analysis

2019 ◽  
Vol 972 ◽  
pp. 129-133
Author(s):  
Yasmeen Taleb Obaidat
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Finite Element Model ◽  
Load Capacity ◽  
Element Model ◽  
Material Behavior ◽  
Nonlinear Material ◽  
Concrete Column ◽  
Reinforced Concrete Column ◽  
Number Of Layers

Little research has been carried out in validating, fiber reinforced polymer (FRP) concrete strengthened column and the effective using partial wrapping. Also the effect of several parameter on strengthen column using the partial wrapping sheet of desired width and thickness around column have not been found out. To this end, a nonlinear 3D finite element model has been developed in current study for CFRP strengthened reinforced concrete column to simulate the behavior accompanied by the effect of partial wrapping with emphasis on load capacity and failure mode. The finite element simulation of CFRP strengthened RC columns is performed using commercial finite element program ABAQUS. Modelling was conducted on reinforced concrete columns with dimensions of 160 x 250 x 960 mm. The finite element model incorporates the nonlinear material behavior of concrete, bilinear stress-strain curve of steel and linear elastic behavior of CFRP material. The concrete was modeled using a plastic damage model. The performance of the FE model was studied by simulating experimental columns from the literature. The load, and strain of CFRP obtained from the FE study were compared with the corresponding experimental results. The FEM results agreed well with the experiments. In addition, to enhance our understanding of the behavior of strengthened reinforced concrete column capacity using partial wrapping the effect of changing the spacing between the CFRP sheets and number of layers were examined. The increase number of layers and decrease spacing give a higher ultimate load capacity, and delay the failure.

Fire Resistance of Reinforced Concrete Corrosion-Damaged Columns of the "Standard" Fire

2019 ◽  
Vol 828 ◽  
pp. 163-169
Author(s):  
Ashot Georgievich Tamrazyan ◽  
Micheal Sergeevich Mineev ◽  
Aishat Urasheva
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Fire Resistance ◽  
Protective Layer ◽  
Operating Conditions ◽  
Corrosive Environment ◽  
Reinforced Concrete Column ◽  
Cross Sectional ◽  
Standard Fire ◽  
The Cross

The article describes the features of the effect of corrosion of reinforcement on the bearing capacity of reinforced concrete columns in a "standard" fire. On the basis of the standard calculation method, the fire resistance of the column was estimated under a four-sided fire effect taking into account the different duration of the fire. The study examined the operation of the column in a corrosive environment, it was assumed that the initiation of corrosion of concrete and reinforcement will occur after 10 years of exploitation. It was found that the destruction of concrete protective layer 25 mm thick in a medium aggressive environment will occur after 25 years, and the diameter of the reinforcement during this period will decrease by 20%. To compare the results, a reinforced concrete column with a section of 400x400mm was calculated under the influence of a “standard” fire under normal operating conditions and taking into account work in a corrosive environment. The results of heat engineering calculations are presented, where the temperature changes in the reinforcement depending on the heating time and reduction of the protective layer thickness, as well as the change in the diameter of the reinforcement and its effect on the bearing capacity are shown. It has been established that reducing the cross-sectional area of the working reinforcement and reducing the cross-sectional dimensions of the column due to the occurring corrosion processes leads to a decrease in the fire resistance limit on the loss of bearing capacity by 58%.

Calculation Method Investigation on Jacketing Reinforcement of RC Eccentric Compressive Column Subjected to Fire

2012 ◽  
Vol 166-169 ◽  
pp. 1548-1553
Author(s):  
Jin Jun Guo ◽  
Yan Lu ◽  
Ping Xian Li
Keyword(s):  
Reinforced Concrete ◽  
Temperature Distribution ◽  
Calculation Method ◽  
Load Capacity ◽  
Concrete Column ◽  
Compressive Failure ◽  
Reinforced Concrete Column ◽  
Rc Column ◽  
Column Section ◽  
Reinforcement Design

Based on eccentric compressive experiments of reinforced concrete column strengthened with jacketing method, the paper calculated and analyzed jacketing reinforcement of RC eccentric compressive column subjected to fire. The calculation procedure of residual load capacity of compressive member after fire was put forward according to temperature distribution at column section. To distinguish tensile or compressive failure of RC column, the formulas of relative balanced depth of compressive zone of jacketing section were deduced as well as the corresponding applied calculation method of norm section load capacity was presented under the second loaded stage. In addition, the reinforcement design and construction of one fire damaged building was conducted in terms of this paper’s method. The good running status of strengthened columns for many years validates the applicability of this method.

Experimental Study on Axial-Compression Reinforced Concrete Column Strengthened by Circular Steel Tube

2011 ◽  
Vol 94-96 ◽  
pp. 1261-1270 ◽  
Author(s):  
Mei Hua Wang
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Axial Compression ◽  
Work Performance ◽  
Load Capacity ◽  
Steel Tube ◽  
Concrete Column ◽  
Reinforced Concrete Column ◽  
Circular Steel Tube ◽  
Core Column

In the case of small increase of cross-section, concrete column strengthened by circular steel tube can increase the bearing capacity greatly as well as ductility. This has resulted in engineering welcome. This paper studied the common work performance of reinforced concrete column strengthened by circular steel tube in three different conditions test of axial compression. The results show that outsourcing steel and core column can be achieved interaction. By strengthening, it can improve the load capacity of the concrete column as well as ductility. With the increase in initial load, although it has little effect on the bearing capacity of reinforced columns, it can affect the ductility to some extent. This paper can provide experimental basis for engineering applications.

scholarly journals Harmonic dynamic loading response of reinforced concrete column

2018 ◽  
Vol 162 ◽  
pp. 04024
Author(s):  
Saba Sabih
Keyword(s):  
Reinforced Concrete ◽  
Power Systems ◽  
Electrical Power ◽  
Three Dimensions ◽  
Concrete Column ◽  
Structural Element ◽  
Reinforced Concrete Column ◽  
Cross Sectional ◽  
Analysis And Design ◽  
Strength Capacity

A reinforced concrete column is classified as compression structural element mostly analyzed and designed due to the applied combinations of dead and live loading with other considered loadings. Industries of considerable or relatively great size, production and electrical utilities are very concerned about the presence of dynamic loads in their electrical power systems. This behavior provides current with different components that are multiples of the fundamental frequency of the system which are called harmonics. Reinforced concrete elements such as column must be checked for the strength capacity and the response due to applied harmonic loading after completed the static analysis and design. In present article evaluations of reinforced concrete columns under the effects of dynamic harmonic loadings are studied. The main parameters are the reinforcement ratio and harmonic ranged loadings. Finite elements approach was adopted to analyze the columns by ANSYS software and all models are simulated in three dimensions. The analysis results indicated that the square cross sections with that rectangular of the same cross sectional area are closed in performance against static and dynamic loadings.

scholarly journals Comparison of Stress-Strain Relationship for Confined Concrete Using Two-Dimensional Fiber-Based Cross-Sectional Analysis

2021 ◽  
Vol 4 (2) ◽  
pp. 93
Author(s):  
Nia Dwi Puspitasari ◽  
Aulia Dewi Fatikasari
Keyword(s):  
Experimental Data ◽  
Reinforced Concrete ◽  
Constitutive Model ◽  
Concrete Column ◽  
Two Dimensional ◽  
Reinforced Concrete Column ◽  
Stress Strain ◽  
Cross Sectional ◽  
Strain Relationship ◽  
Sectional Analysis

Stress-strain relationship is the main parameter to identify the strength, ductility and behavior of the structure. Various constitutive models were created in order to simplify the analytical approach of concrete behavior. In this paper, the behavior of reinforced concrete column is modeled using Attard and Setunge�s (1996) and Mander�s (1988) stress-strain constitutive model. The appropriate model for reinforced concrete column was determined based on the existing experimental data. Two-dimensional simulation of reinforced concrete column using fiber-based cross-sectional analysis in MATLAB is sighted. And the performance of the reinforced concrete column from the experimental data is compared with the analysis result from the simulation. There are two comparation methods used in this research. The first method is to compare the linear regression with the reference line. The smallest degree between the linear regression and the referrence line is expected. The second method is to compare the Root Mean Square Defiation (RMSD) value. The smallest RMSD value is expected to get the most suitable constitutive model compared to the experimental data. From the computational process, it was found that Mander�s Constitutive model is preferaed to be used in further analysis problem concerning reinforced concrete column

DETERMINATION OF THE AREA OF REINFORCEMENT OF REINFORCED CONCRETE COLUMNS OF CIRCULAR CROSS SECTION

2018 ◽  
Vol 8 (3) ◽  
pp. 8-11
Author(s):  
Nikolay A. ILYIN ◽  
Sergey S. MORDOVSKY ◽  
Ekaterina Ye. VASILYEVA ◽  
Valeriya N. TALANOVA
Keyword(s):  
Reinforced Concrete ◽  
Cross Section ◽  
Circular Cross Section ◽  
Mathematical Expression ◽  
Concrete Columns ◽  
Concrete Column ◽  
Longitudinal Reinforcement ◽  
Sectional Area ◽  
Reinforced Concrete Column ◽  
Cross Sectional

A mathematical expression has been developed for determining the cross-sectional area of reinforcement of an eccentrically compressed reinforced concrete column of circular cross section, which makes it possible to simplify consideration of the infl uence of structural indicators and quality parameters of reinforcement and concrete on the required area of longitudinal reinforcement of reinforced concrete column. An example of using this formula in the calculation is shown. This mathematical expression can be used in the design of reinforced concrete columns, racks of power lines and circular supports as the least time-consuming method of engineering calculation, allowing to determine the cross-sectional area of longitudinal reinforcement.

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