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Article
Publication date: 23 August 2019

Shanmukha Shetty, Subrahmanya R.M., Sushanth Bhandary and Thushar Shetty

Columns are structural elements that are predominantly subjected to compressive forces and moments that are to be transferred from the super-structure to the…

Abstract

Purpose

Columns are structural elements that are predominantly subjected to compressive forces and moments that are to be transferred from the super-structure to the sub-structure. The geometrical shape of a column is a significant factor to be considered. The paper aims to discuss this issue.

Design/methodology/approach

Pushover analysis is carried out, to study the behavior of RC frames with rectangular and specially shaped columns for the same building layout.

Findings

Reduction of 27.3 percent in base shear, 67.4 percent in spectral displacement, 66.5 percent reduction in storey displacement, 70.22 percent in storey drift and 0.315 percent reduction in storey shear is observed.

Practical implications

Special shaped RC columns can effectively enhance the structural behavior of high rise structures under seismic excitation in comparison to those with regular shaped RC columns.

Originality/value

Applications of special shaped columns in structures have showed a great deal of reduction in displacement and shear forces developed due to seismic activity, for the same area of concrete and steel as in rectangular columns.

Details

International Journal of Structural Integrity, vol. 11 no. 2
Type: Research Article
ISSN: 1757-9864

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Article
Publication date: 1 February 2021

Nurizaty Zuhan, Mariyana Aida Ab Kadir, Muhammad Najmi Mohamad Ali Mastor, Shek Poi Ngian and Abdul Rahman Mohd. Sam

Concrete-filled steel hollow (CFHS) column is an innovation to improve the performance of concrete or steel column. It is believed to have high compressive strength, good…

Abstract

Purpose

Concrete-filled steel hollow (CFHS) column is an innovation to improve the performance of concrete or steel column. It is believed to have high compressive strength, good plasticity and is excellent for seismic and fire performance as compared to hollow steel column without a filler.

Design/methodology/approach

Experimental and numerical investigation has been carried out to study the performance of CFHS having different concrete in-fill and shape of steel tube.

Findings

In this paper, an extensive review of experiment performed on CFHS columns at elevated temperature is presented in different types of concrete as filling material. There are three different types of concrete filling used by the researchers, such as normal concrete (NC), reinforced concrete and pozzolanic-fly ash concrete (FC). A number of studies have conducted experimental investigation on the performance of NC casted using recycled aggregate at elevated temperature. The research gap and the recommendations are also proposed. This review will provide basic information on an innovation on steel column by application of in-filled materials.

Research limitations/implications

Design guideline is not considered in this paper.

Practical implications

Fire resistance is an important issue in the structural fire design. This can be a guideline to define the performance of the CFHS with different type of concrete filler at various exposures.

Social implications

Utilization of waste fly ash reduces usage of conventional cement (ordinary Portland cement) in concrete production and enhances its performance at elevated temperature. The new innovation in CFHS columns with FC can reduce the cost of concrete production and at the same time mitigate the environmental issue caused by waste material by minimizing the disposal area.

Originality/value

Review on the different types of concrete filler in the CFHS column. The research gap and the recommendations are also proposed.

Details

Journal of Structural Fire Engineering, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2040-2317

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Article
Publication date: 1 April 1983

H. McArthur

About 26,000 Airey Houses were erected during the post war years (1946–55) as part of the house building programme of that period. The Airey House is essentially a…

Abstract

About 26,000 Airey Houses were erected during the post war years (1946–55) as part of the house building programme of that period. The Airey House is essentially a prefabricated concrete structure which was erected on site to form a box. This box was erected upon a concrete raft which acted as the foundation and floor of the dwelling. The basic box was formed from several framed ‘goal posts’ to which thin concrete cladding panels were fastened to the upright columns by copper wire. The vertical loading from the first floor and roof is taken on the vertical columns but may also be shared with the concrete cladding panels (see Figure 1).

Details

Structural Survey, vol. 1 no. 4
Type: Research Article
ISSN: 0263-080X

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Article
Publication date: 21 February 2019

Yagho S. Simões, Fabio M. Rocha and Jorge Munaiar Neto

Isolated steel columns, when exposed to high temperatures, lose strength in a few minutes due to the high thermal conductivity of its constituent material. When these…

Abstract

Purpose

Isolated steel columns, when exposed to high temperatures, lose strength in a few minutes due to the high thermal conductivity of its constituent material. When these structural elements are embedded in walls, the response to exceptional action is altered so that the compartmentation offers an increase in the fire resistance of the columns. Therefore, the purpose of this paper is to analyze the behavior of steel columns inserted in walls subject to thermal action in a numerical context.

Design/methodology/approach

For this purpose, the computational code ABAQUS version 6.14, which applies the finite element method formulation to solve engineering problems, was used.

Findings

The thermo-mechanical modeling, considering the wall only as a compartmentation element, generated few consistent results, leading to the conclusion that the walls influence the structural response of columns in a fire situation.

Originality/value

There is a lack of both numerical and experimental research works. In numerical modeling, the research works found in the literature had difficulties in developing a numerical model that satisfactorily represented steel columns inserted in walls, not being able to adequately understand their behavior at high temperatures. All of them did not consider the influence of masonry on the thermo-structural behavior of the columns. In this paper, this influence was evaluated and discussed.

Details

Multidiscipline Modeling in Materials and Structures, vol. 15 no. 2
Type: Research Article
ISSN: 1573-6105

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Article
Publication date: 10 July 2009

W.K. Chow, Min Lin and Diankui Liu

The fire response of structural reinforced concrete columns is usually justified by the reduction in ultimate load bearing capacity. This is due to the decrease in…

Abstract

Purpose

The fire response of structural reinforced concrete columns is usually justified by the reduction in ultimate load bearing capacity. This is due to the decrease in mechanical strength of steel and concrete upon exposure to a fire. In structural design, it is more desirable to consider the action of load directly. The concept of equivalent accidental load due to a fire might give more convenient structural design data. This paper aims to focus on these issues.

Design/methodology/approach

A theoretical analysis for the equivalent accidental load imposed on reinforced concrete columns (axially loaded columns, uniaxially loaded columns and biaxially loaded columns) exposed to four‐side fires is carried out. The test results of previous research are used as examples and for checking computations. After determining its temperature field, the equivalent accidental load due to fire is calculated using simplified methods. The fire resistance period of reinforced concrete columns can also be determined.

Findings

If the response of a structural element to a fire can be converted into an accidental load, it can be combined with other components such as wind load and earthquake action to give a total design load. With this method, the equivalent accidental load due to a fire and fire resistance of reinforced concrete columns at elevated temperature can be derived directly, and the process is very simple. The equivalent accidental load and fire resistance of reinforced concrete columns exposed to fire on one, two or three sides can also be derived by the same method. However, the thermal performance of steel and concrete cannot be considered during the calculation.

Originality/value

A simplified approach of equivalent accidental load due to fire is proposed. Much simpler guides can be drafted in structural fire design.

Details

Structural Survey, vol. 27 no. 3
Type: Research Article
ISSN: 0263-080X

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Article
Publication date: 8 April 2019

Lin Li

Damage detection of frame structures is important for guaranteeing the safety of people’s lives and property. Sensitivity analysis is an effective method for damage…

Abstract

Purpose

Damage detection of frame structures is important for guaranteeing the safety of people’s lives and property. Sensitivity analysis is an effective method for damage identification. The purpose of this paper is to conduct a sensitivity analysis of beam–column joint rotation angles for frame structures with limited flexural stiffness beams.

Design/methodology/approach

First, based on the D-value method and the assumption of inflection points, statically indeterminate frames were transformed to statically determinate structures, and the expressions of beam–column joint rotation angles were derived. Next, the sensitivity coefficients of beam–column joint rotation angles were obtained by taking the derivative of the expressions of beam–column joint rotation angles with respect to the linear stiffness of column. Finally, the expressions of the sensitivity coefficients were verified by a numerical example.

Findings

The analytical solutions of the sensitivity coefficients are in good agreement with finite element results. The results show that the beam–column joint rotation angles of damaged column decrease and those of intact columns within the same story increase when damage occurs.

Originality/value

In this study, the sensitivity coefficients of beam–column joint rotation angles with respect to the linear stiffnesses of columns were derived for frame structures. Based on the result of the sensitivity analysis, the relationship between the changes of beam–column joint rotation angles and damaged columns is revealed. The findings provide an important base to further detect damage of frame structures.

Details

International Journal of Structural Integrity, vol. 10 no. 2
Type: Research Article
ISSN: 1757-9864

Keywords

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Article
Publication date: 1 August 1999

Hsien‐Tang Tsai

In the Taguchi’s experimentations, orthogonal arrays, interaction tables, and linear graphs are provided for planning experiments, but they become quite unwieldy when the…

Abstract

In the Taguchi’s experimentations, orthogonal arrays, interaction tables, and linear graphs are provided for planning experiments, but they become quite unwieldy when the number of runs is large. The purpose of this article is to propose a quick and easy method for obtaining two‐factor interaction columns in two‐level orthogonal arrays. Geometrical designs proposed by Plackett and Burman are two‐level orthogonal arrays and can be obtained very easily by a successive doubling method. Based on the property of doubling, a NR method using a number representation system whose base is a power of 2 is derived in this article for obtaining two‐factor interaction columns in geometrical designs. Furthermore, since Taguchi’s two‐level orthogonal arrays are obtainable by successive doubling with some column permutations, it is shown that their two‐factor interaction columns can be obtained directly by using the NR method without looking up tables.

Details

International Journal of Quality & Reliability Management, vol. 16 no. 6
Type: Research Article
ISSN: 0265-671X

Keywords

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Article
Publication date: 26 November 2020

Oliver Bahr

Unbraced one-bay composite frames are an interesting load-bearing structure for buildings with up to three storeys. However, their fire design is demanding given the lack…

Abstract

Purpose

Unbraced one-bay composite frames are an interesting load-bearing structure for buildings with up to three storeys. However, their fire design is demanding given the lack of simplified design methods. This paper aims to deepen the understanding of the load-bearing behaviour of both unbraced and braced frames when exposed to fire.

Design/methodology/approach

In a previous paper, a numerical model for the fire design of these frames was established and validated with good agreement against fire tests. In the current paper, this model was used to compare the typical differences between braced, semi-braced and unbraced composite frames under fire conditions. Further studies addressed the effect of different heating regimes, i.e. partial fire exposure of the columns in the frames and varying location of the ISO standard fire.

Findings

Numerical investigations showed that it is necessary to take local failure and deformation limits of the fire-exposed frames into account. On this basis, unbraced composite frames can compete with braced frames as they have to endure less thermal restraints than braced frames.

Originality/value

In contrast to other investigations on frames, the numerical model is able to take into account the shear failure, which is especially important within the frame corners. Using this model, it is shown that limited sway is reasonable to reduce thermal restraints and hence local stresses. In this regard, the concept of semi-rigid composite joints with a distinct amount of reinforcement has proven to be very rational in fire design.

Details

Journal of Structural Fire Engineering, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2040-2317

Keywords

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Article
Publication date: 7 December 2020

Fatimah De'nan, Nor Salwani Hashim and Zafira Nur Ezzati Mustafa

The purpose of this study is to know the buckling capacity for cold-formed C-column with perforation. Cold-formed C-column have been used in interior wall construction…

Abstract

Purpose

The purpose of this study is to know the buckling capacity for cold-formed C-column with perforation. Cold-formed C-column have been used in interior wall construction. The concept of web perforation in the column has been introduced to the construction sector to overcome the issue of material cost.

Design/methodology/approach

Initially, the determination of the suitable spacing for the space column for the affordable house is investigated. Analysis house frame has been done in STAAD Pro. (Staad Pro, 2003) software using cold-formed C-column without perforation. Perforation with circular shape has been used in this study with the size of 0.4, 0.6 and 0.8 D (D = 180 mm). Perforation spacing is 150, 250 and 350 mm are adopted.

Findings

For the specimen with 0.4 D perforation and the edge distance is 539 mm have the highest buckling capacity (26.59 kN). Reduction of buckling capacity is 5.31% from cold-formed C-column without perforation and reduction of the volume is −2.16%. For the same case with 0.8 D perforation, the buckling capacity reduces with 22.52% and volume is −6.85%.

Originality/value

The conclusion of this analysis, C-column without perforation have higher buckling capacity compare to C-column with perforations.

Details

World Journal of Engineering, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1708-5284

Keywords

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Book part
Publication date: 27 October 2005

Janice McCabe

Medicalization is the increasing social control of the everyday by medical experts. It is a key concept in the sociology of health and illness because it sees medicine as…

Abstract

Medicalization is the increasing social control of the everyday by medical experts. It is a key concept in the sociology of health and illness because it sees medicine as not merely a scientific endeavor, but a social one as well. Medicalization is a “process whereby more and more of everyday life has come under medical dominion, influence, and supervision” (Zola, 1983, p. 295); previously these areas of everyday life were viewed in religious or moral terms (Conrad & Schneider, 1980; Weeks, 2003). More specifically, medicalization is the process of “defining a problem in medical terms, using medical language to describe a problem, adopting a medical framework to understand a problem, or using a medical intervention to ‘treat’ it” (Conrad, 1992, p. 211). Sociologists have used this concept to describe the shift in the site of decision-making and knowledge about health from the lay public to the medical profession.

Details

Sociological Studies of Children and Youth
Type: Book
ISBN: 978-0-76231-256-6

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