Recent Developments in Composite Construction in the USA

2005 ◽  
Vol 8 (3) ◽  
pp. 259-274 ◽  
Author(s):  
Roberto T. Leon
Keyword(s):  
Reinforced Concrete ◽  
Design Procedure ◽  
Concrete Columns ◽  
Short Description ◽  
Smooth Transition ◽  
American Institute ◽  
Recent Developments ◽  
The Usa ◽  
Column Design ◽  
Main Change

This paper presents an overview of the proposed changes in composite design provisions for the upcoming American Institute of Steel Construction (AISC) 2005 Specification. The main change insofar as member design is concerned relates to how composite column design is handled. The new provisions will provide a more smooth transition between design of composite and reinforced concrete columns and a more rational, mechanistically-based design procedure. Insofar as member detailing is concerned, the main change is in the strength values for shear studs, which have been considerably lowered under some circumstances. The paper also presents some ongoing developments in composite floor and lateral load resisting systems, and concludes with a short description of an unusual composite truss.

scholarly journals Development of design procedures for the flexural strength and ductility of reinforced concrete bridge columns

1986 ◽  
Vol 19 (3) ◽  
pp. 200-212 ◽  
Author(s):  
F. A. Zahn ◽  
R. Park ◽  
M. J. N. Priestley ◽  
H. E. Chapman
Keyword(s):  
Reinforced Concrete ◽  
Flexural Strength ◽  
Design Method ◽  
Design Procedure ◽  
Concrete Columns ◽  
Cyclic Stress ◽  
Code Design ◽  
Reinforced Concrete Column ◽  
Reinforced Concrete Columns ◽  
Design Charts

The assumptions and methods of analysis used to define the flexural strength and the available limit curvature of reinforced concrete columns sections are discussed. The results of cyclic moment-curvature analyses of a large range of reinforced concrete column sections, using cyclic stress-strain relationships for the steel and for the concrete, are outlined and the important variables and their influence on the available strength and curvature ductility are identified. Examples of design charts derived from these analytical results are discussed and a flow chart outlining the whole seismic resistance design procedure for bridge piers is introduced. The quantity of confining steel determined using the design charts is compared with the corresponding quantity required by the current New Zealand concrete design code equations. Finally a possible future development is discussed that would lead to an improvement of the code design method used to provide sufficient ductility in the plastic hinges of reinforced concrete columns.

Developments in the seismic design of reinforced concrete frames in New Zealand

1981 ◽  
Vol 8 (2) ◽  
pp. 91-113 ◽  
Author(s):  
T. Paulay
Keyword(s):  
Reinforced Concrete ◽  
New Zealand ◽  
Experimental Studies ◽  
Design Procedure ◽  
Capacity Design ◽  
Concrete Frames ◽  
Plastic Hinges ◽  
Reinforced Concrete Frames ◽  
Code Of Practice ◽  
Recent Developments

A review of recent developments in the formulation of a design approach for ductile earthquake resisting reinforced concrete frames is presented. In particular the concepts of a deterministic design procedure, termed "capacity design," the advantages of moment redistribution, and the effects of gravity load dominance are discussed. In capacity design (a detailed definition of the term is given in Sect. 2.1) the designer attempts to enforce the development of a unique and desirable pattern of plastic hinges when these are required to dissipate significant amounts of energy to ensure the necessary hysteretic damping. The application of a capacity design procedure in determining the design actions for columns of multistorey frames is examined. Some issues relevant to instability during the inelastic dynamic response of frames are also discussed. Using recent experimental evidence, the inelastic behaviour of reinforced concrete columns, shear effects on potential plastic hinges, and special features of the behaviour of beam–column joints, when these are subjected to severe earthquake simulating reversed cyclic loading, are briefly described. Conclusions drawn from these recent experimental studies, which are being considered for incorporation into the new New Zealand concrete design code of practice, are also reported.

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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