scholarly journals Reinforced concrete bridge pier ductility analysis for different levels of detailing

2017 ◽  
Vol 10 (5) ◽  
pp. 1042-1050
Author(s):  
R. W. SOARES ◽  
S. S. LIMA ◽  
S. H. C. SANTOS
Keyword(s):  
Reinforced Concrete ◽  
Axial Loading ◽  
Structural Element ◽  
Reinforced Concrete Column ◽  
Elastoplastic Behavior ◽  
Response Modification Factor ◽  
Concrete Confinement ◽  
Plastic Displacement ◽  
Displacement Based ◽  
Ductility Capacity

Abstract The structural design under seismic loading has been for many years based on force methods to consider the effects of energy dissipation and elastoplastic behavior. Currently, displacement-based methods are being developed to take into account elastoplastic behavior. These methods use moment-curvature relationships to determine the ductility capacity of a structural element, which is the deformation capacity of the element before its collapse. The greater the plastic displacement or rotation a structural member can achieve before it collapses, the more energy it is capable of dissipating. This plastic displacement or rotation capacity of a member is known as the member ductility, which for reinforced concrete members is directly related to efficient concrete confinement. This study investigates at which extents transverse reinforcement detailing influences reinforced concrete column ductility. For this, a bridge located in Ecuador is modeled and analyzed, and its ductility evaluated considering several cases of axial loading and concrete confinement levels. After the performed displacement-based analyses, it is verified whether the response modification factor defined by AASHTO is adequate in the analyzed case.

scholarly journals Behaviour of Steel Reinforced Concrete Section with CFRP Wrapping Under Axial Compression

2019 ◽  
Vol 9 (1) ◽  
pp. 1955-1958 ◽  
Keyword(s):  
Reinforced Concrete ◽  
Concrete Columns ◽  
Radial Compression ◽  
Axial Loads ◽  
Structural Element ◽  
Reinforced Concrete Column ◽  
Element Analysis ◽  
Steel Reinforced Concrete ◽  
Tubular Columns ◽  
Cfrp Wrapping

The composite structural element under study is a carbon fiber wrapped, steel I section reinforced concrete column. The wrapped CFRP is under tension and reinforced concrete under radial compression. The aim of the research is to determine the behavior of the composite structural element under axial loads. The Stress-strain characteristics and load bearing capacity of control and CFRP wrapped tubular columns were determined experimentally. Further, Finite element analysis of steel, reinforced concrete and CFRP wrapped concrete columns sections, was conducted using ANSYS Workbench 15.0 software. The experimental and analytical results were compared.

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.

Displacement-based seismic design of regular reinforced concrete shear wall buildings

2011 ◽  
Vol 38 (6) ◽  
pp. 616-626 ◽  
Author(s):  
JagMohan Humar ◽  
Farrokh Fazileh ◽  
Mohammad Ghorbanie-Asl ◽  
Freddy E. Pina
Keyword(s):  
Reinforced Concrete ◽  
Seismic Design ◽  
Pushover Analysis ◽  
Shear Wall ◽  
Base Shear ◽  
Ductility Demand ◽  
Inelastic Demand ◽  
Displacement Based ◽  
Ductility Capacity ◽  
Shear Demand

A displacement based method for the seismic design of reinforced concrete shear wall buildings of regular shape is presented. For preliminary design, approximate estimates of the yield and ultimate displacements are obtained, the former from simple empirical relations, and the latter to keep the ductility demand within ductility capacity and to limit the maximum storey drift to that specified by the codes. For a multi-storey building, the structure is converted to an equivalent single-degree-of-freedom system using an assumed deformation shape that is representative of the first mode. The required base shear strength of the system is determined from the inelastic demand spectrum corresponding to the ductility demand. In subsequent iterations a pushover analysis for the force distribution based on the first mode is used to obtain better estimates of yield and ultimate displacements taking into account stability under P–Δ effect. A multi-mode pushover analysis is carried out to find more accurate estimates of the shear demand.

Accelerated corrosion investigation of axially loaded reinforced concrete elements

2014 ◽  
Vol 61 (4) ◽  
pp. 215-223 ◽  
Author(s):  
Christos Zeris ◽  
George Batis ◽  
Vassilios Mouloudakis ◽  
John Marakis
Keyword(s):  
Reinforced Concrete ◽  
Axial Load ◽  
Load Capacity ◽  
Axial Loading ◽  
Load Level ◽  
Concrete Cover ◽  
Chloride Ingress ◽  
Reinforced Concrete Column ◽  
Accelerated Corrosion ◽  
Content Type

Purpose – This paper aims to present results of an experimental investigation on a series of scaled reinforced concrete column elements which were subjected to chloride exposure under accelerated conditions under a concurrent service axial load, over a period. In the presence of an axial load, directed microcracks of increasing density and width are introduced in the concrete mass, depending on the axial load level. Such cracks are believed to enhance the intrusion rate of chlorides in the concrete, relative to what is obtained in the normally performed unloaded specimen tests. Design/methodology/approach – Eighteen column specimens were tested over two chloride exposure periods, of duration up to a maximum of six months. Three different service axial load levels were considered, namely, none, 22 per cent and 43 per cent of the normalized axial load capacity of the columns. Findings – The results indicate that the specimens loaded to the higher axial load, which closely resembles actual service situation of such type of elements, exhibited up to ten times faster rates of induced current flow under a constant applied voltage of 500 mV, compared to the unloaded and less loaded specimens. Practical implications – It is proven that the presence of axial load influences the rate of chloride ingress in columns and, therefore, should be taken into account in estimating the concrete cover of such elements in durability design. Originality/value – The influence of axial loading on corrosion rate has not been considered in published experimental and analytical studies of chloride ingression. These studies have typically so far considered the accelerated corrosion of unloaded column specimens.

On lap splice length of lap-spliced crossties for reinforced concrete columns under cyclic loading

2020 ◽  
Vol 23 (12) ◽  
pp. 2669-2678
Author(s):  
Tai-Kuang Lee ◽  
Cheng-Cheng Chen
Keyword(s):  
Reinforced Concrete ◽  
Cyclic Loading ◽  
Concrete Columns ◽  
Seismic Resistance ◽  
Reinforced Concrete Column ◽  
Reinforced Concrete Columns ◽  
Lap Splice ◽  
Concrete Confinement ◽  
Confining Effect

A lap-spliced crosstie comprises two J-shaped rebars, each with a 180° hook at one end and straight at the other end. Six large reinforced concrete columns subjected to lateral cyclic loading were tested. The results indicated the following: (1) the confining effect of horizontally lap-spliced crossties is similar to that of vertically lap-spliced crossties. (2) Splice length of the lap-spliced crossties that is smaller than the code requirement can also provide sufficient concrete confinement. (3) A method for determining required lap splice length for lap-spliced crossties is proposed. (4) The lap-spliced crosstie can considerably improve the constructability of the crossties. Furthermore, the construction quality of reinforced concrete column reinforcement and the seismic resistance capability of reinforced concrete structures can be significantly upgraded.

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 Effect of Reinforced Concrete Jacketing on Axial Load Capacity of Reinforced Concrete Column

2020 ◽  
Vol 6 (7) ◽  
pp. 1266-1272
Author(s):  
Praveen Anand ◽  
Ajay Kumar Sinha
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Load Capacity ◽  
Concrete Surface ◽  
Structural Element ◽  
Reinforced Concrete Column ◽  
Rc Column ◽  
Finite Element Software ◽  
Design Values ◽  
Abaqus Software

Whenever a member of a structure becomes structurally deficient, it becomes vulnerable to the existing load and for the additional loads that it may be subjected to in the coming future. Since columns are the most important structural element, the structural retrofit of columns, relative to other structural elements is of prime importance. This study intends to investigate the performance and behaviour of an RC column jacketed with Reinforced Concrete columns under axial loads. The objective of this paper is to find out the efficiency of RC jacket in enhancing the strength of an existing RC column. A mathematical design based upon Indian Standards codes has been designed to identify the behaviour of jacketed RC columns. This has been followed by a finite element based numerical simulation using the same material properties as used in the process of designing. The simulation has been done in ABAQUS software with appropriate contact modelling. The analytical model considers that there is no bond slippage between the existing and new concrete surface i.e. the bond between the existing and new concrete is assumed to be perfect. This perfect bond between the surfaces has been modelled by using appropriate constraints in ABAQUS software. The finite element models show fair agreement with the designed values in terms of ultimate capacity and failure mode. The load bearing capacity enhancement of the RC jacketed column has been found to increase substantially. The enhancement capacity results obtained from the finite element software differs about 16-25% from the design values.

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