scholarly journals Analytical study of in-plane buckling of longitudinal bars in reinforced concrete columns under extreme earthquake loading

2017 ◽  
Vol 134 ◽  
pp. 48-60 ◽  
Author(s):  
Alireza Nojavan ◽  
Arturo E. Schultz ◽  
Shih-Ho Chao
Keyword(s):  
Reinforced Concrete ◽  
Analytical Study ◽  
Concrete Columns ◽  
Earthquake Loading ◽  
Reinforced Concrete Columns

scholarly journals The use of Grade 380 steel for transverse confining reinforcement in columns

1987 ◽  
Vol 20 (2) ◽  
pp. 99-115
Author(s):  
F. A. Zahn ◽  
R. Park ◽  
M. J. N. Priestley
Keyword(s):  
Reinforced Concrete ◽  
Axial Load ◽  
Analytical Study ◽  
Concrete Columns ◽  
Lateral Loading ◽  
Transverse Reinforcement ◽  
Reinforced Concrete Columns ◽  
Ductility Factor ◽  
Strain Behaviour ◽  
Curvature Ductility

The results of recent experimental and analytical studies of the stress-strain behaviour of concrete confined by New Zealand manufactured Grade 275 or Grade 380 reinforcing steel are presented. First, the behaviour of three pairs of concentrically loaded reinforced concrete columns containing spirals from either Grade
275 or Grade 380 steel are compared, including the stage at which spiral fracture occurred. Second, the results of tests on four reinforced concrete columns containing Grade 380 spiral or rectangular hoop reinforcement and subjected to combined axial
load and cyclic lateral loading are reported. An analytical
study which was conducted to determine the available curvature ductility factor at the stage of fracture of the transverse reinforcement is described. The results are used to give a guideline for the safe use of Grade 380 steel as transverse confining reinforcement.

SETTING A DIAGRAM APPROACH TO CALCULATING VIBRATED, CENTRIFUGED AND VIBROCENTRIFUGED REINFORCED CONCRETE COLUMNS WITH A VARIATROPIC STRUCTURE

2020 ◽  
pp. 22-34
Author(s):  
Л. Р. Маилян ◽  
С. А. Стельмах ◽  
Е. М. Щербань ◽  
М. П. Нажуев
Keyword(s):  
Experimental Data ◽  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Cross Section ◽  
Concrete Columns ◽  
Reinforced Concrete Columns ◽  
The Cross ◽  
Concrete Elements ◽  
Diagram Approach

Состояние проблемы. Железобетонные элементы изготавливаются, как правило, по трем основным технологиям - вибрированием, центрифугированием и виброцентрифугированием. Однако все основные расчетные зависимости для определения их несущей способности выведены, исходя из основного постулата - постоянства и равенства характеристик бетона по сечению, что реализуется лишь в вибрированных колоннах. Результаты. В рамках диаграммного подхода предложены итерационный, приближенный и упрощенный способы расчета несущей способности железобетонных вибрированных, центрифугированных и виброцентрифугированных колонн. Выводы. Расчет по диаграммному подходу показал существенно более подходящую сходимость с опытными данными, чем расчет по методике норм, а также дал лучшие результаты при использовании дифференциальных характеристик бетона, чем при использовании интегральных и, тем более, нормативных характеристик бетона. Statement of the problem. Reinforced concrete elements are typically manufactured according to three basic technologies - vibration, centrifugation and vibrocentrifugation. However, all the basic calculated dependencies for determining their bearing capacity were derived using the main postulate, i.e., the constancy and equality of the characteristics of concrete over the cross section, which is implemented only in vibrated columns. Results. Within the framework of the diagrammatic approach, iterative, approximate and simplified methods of calculating the bearing capacity of reinforced concrete vibrated, centrifuged and vibrocentrifuged columns are proposed. Conclusions. The calculation according to the diagrammatic approach showed a significantly better convergence with the experimental data than that using the method of norms, and also performs better when using differential characteristics of concrete than when employing integral and particularly standard characteristics of concrete.

Experimental Study on the Effect of Moisture Content on Hysteretic Behavior of Reinforced Concrete Columns

2018 ◽  
Vol 12 (1) ◽  
pp. 47-61
Author(s):  
Wenjuan Lv ◽  
Baodong Liu ◽  
Ming Li ◽  
Lin Li ◽  
Pengyuan Zhang
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Moisture Content ◽  
Early Stage ◽  
Damping Ratio ◽  
Concrete Columns ◽  
Hysteretic Behavior ◽  
Cyclic Test ◽  
Experimental Result ◽  
Reinforced Concrete Columns

Background: For reinforced concrete structures under different humid conditions, the mechanical properties of concrete are significantly affected by the moisture content, which may result in a great change of the functional performance and bearing capacity. Objective: This paper presents an experiment to investigate the influence of the moisture content on the dynamic characteristics and hysteretic behavior of reinforced concrete column. Results: The results show that the natural frequency of reinforced concrete columns increases quickly at an early stage of immersion, but there is little change when the columns are close to saturation; the difference between the natural frequencies before and after cyclic test grows as the moisture content rises. The damping ratio slightly decreases first and then increases with the increase of moisture content; the damping ratio after the cyclic test is larger than before the test due to the development of the micro-cracks. Conclusion: The trend of energy dissipation is on the rise with increasing moisture content, although at an early stage, it decreases slightly. According to the experimental result, a formula for the moisture content on the average energy dissipation of reinforced concrete columns is proposed.

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