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

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.

2020 ◽  
Vol 6 (1) ◽  
pp. 27
Author(s):  
Yohanes Laka Suku ◽  
Kristoforus Je

Holes are often made inside the column structure for plumbing, mechanical, and electrical installation purposes may affect the structural performance of the column. Therefore, this paper aims to model and analyze the effect of holes in reinforced concrete column structures due to lateral loads. Data were obtained from the reference frame structure of the previous researcher, with varying centric column holes of 0%, 2%, 4%, 6%, 8%, 10%, and 12%, respectively to the column cross-sectional area. Furthermore, a hole with a ratio of 4% to the column cross-sectional area was placed at 5 and 10 mm eccentric to the center of column cross-section to examine the influence of holes position in the perforated column. The frame structure was modelled and analyzed by Finite Element (FE) using ABAQUS software. The result showed that the maximum load, displacement, and crack pattern resulted from the model is close to the experimental result. The results of the analysis showed that with the hole size of 2% to 12% of the column cross-sectional area, the frame strength was reduced by 5.43% to 15.56%.  The frame strength was also reduced by 2.77% and 6.14% when the hole placed 5mm and 10 mm eccentric to the center of the column cross-section area. The displacement of the frame also decreases by 59.63% to 74.60% when the holes with the ratio of 2% to 12% to the column cross-sectional area exist in the column. The existence of eccentric holes on the column reduced the performance of the frame structure, by decreasing its strength, displacement and ductility.


2013 ◽  
Vol 351-352 ◽  
pp. 401-405
Author(s):  
Cheng Zhu Qiu ◽  
Gang Yang

The steel reinforced concrete column is one of the important members for structures, it is essential to study the high temperature performance of concrete column. The numerical simulation research is done using finite element software ANSYS. Under the high temperature, the analysis of the compressive bearing capacity and flexural capacity of the concrete columns strengthened by CFRP is done, and the compressive bearing capacities of different cross-section concrete columns strengthened with CFRP are tested.


2020 ◽  
Vol 10 (3) ◽  
pp. 9-14
Author(s):  
Nikolay A. ILYIN ◽  
Sergey S. MORDOVSKIY ◽  
Yulia A. POTATYEVA ◽  
Ksenia V. REZYAPKINA

The developed method for assessing fi re resistance relates to the fi eld of fi re safety of buildings and structures and can be used to classify a reinforced concrete column of circular cross-section according to fi re resistance indicators. The essence of the proposed solution is to assess the design limit of fi re resistance of a reinforced concrete column of circular cross-section for the loss of bearing capacity under fi re conditions according to a set of single quality indicators without direct testing. The description of the process of resistance of a reinforced concrete column to fi re impact is presented by a mathematical relationship that takes into account the dimensions of the cross-section of the column, the degree of reinforcement, the intensity of force stresses, the normative strength of concrete to the resistance to axial compression and the rate of thermal diff usion of concrete. To determine the fi re resistance limit of a reinforced concrete column with a circular cross-section, an analytical expression that combines all the described indicators is proposed. The proposed method for determining fi re resistance refers to a thermal strength problem, which makes it possible to determine the fi re resistance of a reinforced concrete column of circular cross-section without full-scale fi re exposure, and reduces economic costs.


2019 ◽  
Vol 22 (12) ◽  
pp. 2605-2619
Author(s):  
Denghu Jing ◽  
Shuangyin Cao ◽  
Theofanis Krevaikas ◽  
Jun Bian

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.


2018 ◽  
Vol 8 (1) ◽  
pp. 4-9
Author(s):  
Sergey S. MORDOVSKY ◽  
Rustam I. DAVLIKAMOV

Theoretical studies of reinforced concrete eccentrically compressed columns of circular cross-section on strength indexes are analyzed. These studies rely on the use of a nonlinear deformation model that approximates the work of concrete to real experimental conditions. A comparative analysis of the results of calculating the strength of reinforced concrete columns of circular cross-section is carried out according to the methodology proposed in the current set of rules, is the author’s program for determining the stress-strain state of a reinforced concrete column of circular cross-section implemented in the MathCad software environment. The results of a numerical experiment are compared in the form of a fi nite-element model in the Lira-CAD program complex using a nonlinear deformation model. Calculations and schemes are given taking into account the possibility of conducting an experimental study.


2012 ◽  
Vol 4 (4) ◽  
pp. 320-325
Author(s):  
Aidas Jokūbaitis ◽  
Arnoldas Šneideris

The article discusses principles calculating resistance of a reinforced concrete column to fire. The paper provides column calculation models, the main characteristics of materials and characteristic stress set points applying finite element program SolidWorks. A comparative analysis of stresses in the cross-section of the reinforced concrete column and the reinforced concrete column strengthened with a metallic shell is made. Santrauka Analizuojami gelžbetoninės kolonos atsparumo ugniai skaičiavimo principai. Pateikiami baigtinių elementų programa SolidWorks sudaryti kolonų skaičiuojamieji modeliai, pagrindinės medžiagų charakteristikos ir būdingi įtempių nustatymo taškai. Atliekama gelžbetoninės ir sustiprintos metaliniu apvalkalu gelžbetoninės kolonos įtempių skerspjūvyje lyginamoji analizė.


2012 ◽  
Vol 479-481 ◽  
pp. 2041-2045
Author(s):  
Yue Qi

Based on experimental research on plain concrete columns with high strength concrete core, the formula to predict the bearing capacity of concrete columns with high strength concrete core under axial compression loading was brought forward in previous paper, in order to verify the formula whether right, axial compression test including 3 concrete columns with high strength concrete core and 1 ordinary reinforced concrete column were completed, and the failure characteristic was analyzed additionally. According to experimental results, it can be shown that the failure modes of concrete columns with high strength concrete core are similar to that of ordinary reinforced concrete columns, however, the bearing capacity of concrete columns with high strength concrete core is significant higher compared with that of ordinary reinforced concrete column; the results of the bearing capacity obtained by the formula (2) was in good agreement with the experimental results.


2008 ◽  
Vol 400-402 ◽  
pp. 269-274 ◽  
Author(s):  
Naveed Anwar ◽  
Mohammad Qaasim

Several parameters and corresponding performance of reinforced concrete column cross-sections of different shapes (square, rectangular, circular, T-shape, I-shape, cross-shape, L-shape and C-shape) under various loading conditions have been studied in order to determine the suitable and optimum cross-sections for strength and ductility. In each cross-section shape, parameters include compressive strength of concrete (f’c), tensile strength of steel (fy), steel ratio (As/Ag), and angle of bending. In order to demonstrate the behavior and performance of the sections in terms of strength and ductility, CSISectionBuilder software was used to define the stress-strain curve for concrete and steel and then compute the moment-curvature relationship for each section. Considering different sections, the number of parameters in every section and various loading conditions, a total of around 1,800 sections were analyzed. The comparison procedures started within each section shape, and then across different sections in order to determine the most suitable cross-section for strength and ductility. Results of the study are deemed very useful in the system selection and preliminary design of important structures such as buildings with complicated geometry and high architectural demand including bridge piers and hydraulic structures.


Author(s):  
Maurício Castelo Branco de Noronha Campos ◽  
Paulo Marcelo Vieira Ribeiro ◽  
Romilde Almeida de Oliveira

abstract: This study addresses a numerical analysis of reinforced concrete columns in which the lengths are significantly larger than their widths with a rectangular cross section. Numerical simulations of 1,440 cases were performed, each case simulated with the single bar model, isolated bar model and mesh model, in addition, 3D model simulations were carried out. For the validation of 3D models and bar models, comparisons were made between the numerical simulation e experimental results of 24 reinforced concrete columns. Second order effects were analyzed on the vertical moment at the edge of the columns in which the lengths are significantly larger than the widths (localized second-order effects) and also the values of the horizontal moments along the cross sectional length in the mesh model. Influences of the main variables were observed influencing the behavior of the columns in which the lengths are significantly larger than their widths: the ratio between the cross sectional dimensions, the slenderness and the stresses (normal stress and bending moment around the axis of greatest inertia).


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