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Article
Publication date: 1 October 2003

H.Y. Leung and R.V. Balendran

Use of fibre‐reinforced polymer (FRP) composite rods, in lieu of steel rebars, as the main flexural reinforcements in reinforced concrete (RC) beams have recently been suggested…

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Abstract

Use of fibre‐reinforced polymer (FRP) composite rods, in lieu of steel rebars, as the main flexural reinforcements in reinforced concrete (RC) beams have recently been suggested by many researchers. However, the development of FRP RC beam design is still stagnant in the construction industry and this may be attributed to a number of reasons such as the high cost of FRP rods compared to steel rebars and the reduced member ductility due to the brittleness of FRP rods. To resolve these problems, one of the possible methods is to adopt both FRP rods and steel rebars to internally reinforce the concrete members. The effectiveness of this new reinforcing system remains problematic and continued research in this area is needed. An experimental study on the load‐deflection behaviour of concrete beams internally reinforced with glass fibre‐reinforced polymer (GFRP) rods and steel rebars was therefore conducted and some important findings are summarized in this paper.

Details

Structural Survey, vol. 21 no. 4
Type: Research Article
ISSN: 0263-080X

Keywords

Article
Publication date: 23 October 2020

Jiaqiang Chen

The main supporting frame of steel structure buildings is steel, and the beam-column joints of the steel structure directly affect the stability and strength of the supporting…

Abstract

Purpose

The main supporting frame of steel structure buildings is steel, and the beam-column joints of the steel structure directly affect the stability and strength of the supporting frame.

Design/methodology/approach

This paper briefly introduced the beam-column joints which are used for ensuring the stability of buildings in the steel structure building, selected the fabricated beam-column joints which were different from the traditional welding methods, tested the fabricated beam-column joints with the reaction frame and jack and detected the influence of the thickness and length of the splice plate on the mechanical properties of joints.

Findings

The results showed that the joint stress and the displacement in the vertical direction increased under greater load no matter which kind of fabricated joint was used; under the same load, the thickness and length of the splice significantly affected the mechanical properties of joints, and the larger the thickness and length, the smaller the joint stress and displacement in the vertical direction.

Originality/value

To sum up, increasing the thickness or length of the splice plate of the fabricated joint can effectively improve the mechanical properties of joints.

Details

International Journal of Building Pathology and Adaptation, vol. 39 no. 4
Type: Research Article
ISSN: 2398-4708

Keywords

Article
Publication date: 28 February 2019

Ataollah Taghipour Anvari, Mustafa Mahamid, Michael McNallan and Mohammadreza Eslami

The purpose of this paper is to present the effect of damaged fireproofing on structural steel members. This study will show that a minor damage in fireproofing will reduce the…

Abstract

Purpose

The purpose of this paper is to present the effect of damaged fireproofing on structural steel members. This study will show that a minor damage in fireproofing will reduce the fire rating of members significantly. Damaged fireproofing happens in structures due to various reasons, and the question is always how effective is this fireproofing? This paper presents the results of one type of fireproofing and presents a parametric study on the size of damage and its effect on fire resistance of structural steel members.

Design/methodology/approach

The study has been performed using numerical methods, thermal and structural finite element analysis. The analysis method has been verified by experimental results.

Findings

Small fire protection damage or loss leads to significant rise of temperature at the damaged parts and causes severe fire resistance reduction of beams. The higher fire protection damage’s extension at the bottom flange of the steel beams does not have any major influence on the rate of reduction of fire resistance of the beams. Steel beams experience greater fire resistance reduction at higher load levels because of the existing of higher stresses and loads within the steel beam section.

Research limitations/implications

The study has been performed using finite element analysis, and it covers a wide range of practical sizes. However, experimental work will be performed by the researchers when funding is granted.

Practical implications

The study provides researchers and practitioners with an estimate on the effect of damaged fireproofing on fire resistance of structural steel beams.

Social implications

Understanding the effect of the effect of damaged fireproofing helps in estimating the fire resistance of structural steel members, which may protect collapses and disasters.

Originality/value

The research is original; extensive literature review has been performed, and this research is original.

Details

Journal of Structural Fire Engineering, vol. 10 no. 1
Type: Research Article
ISSN: 2040-2317

Keywords

Article
Publication date: 23 January 2019

Mustafa Mahamid, Ataollah Taghipour Anvari, Ines Torra-Bilal, Tom Brindley and Michael McNallan

The purpose of this paper is to investigate different types of fire on structural steel members with damaged fireproofing. Two types of fire scenarios are considered, ASTM E119…

192

Abstract

Purpose

The purpose of this paper is to investigate different types of fire on structural steel members with damaged fireproofing. Two types of fire scenarios are considered, ASTM E119 fire and Hydrocarbon fire. In industrial facilities such as oil refineries, certain units maybe subjected to hydrocarbon fire, and its effect might be different than standard fire. The purpose of this study is to compare both types of fire scenarios on steel beams with damaged fireproofing and determine the fire rating of the damaged beams under each fire scenario.

Design/methodology/approach

The study is performed using computational methods, thermal-stress finite element analysis that is validated with experimental results. The results of practical beam sizes and typical applied loads in such structures have been plotted and compared with steel beams with non-damaged fireproofing.

Findings

The results show significant difference in the beam fire resistance between the two fire scenarios and show the fire resistance for beam under each case. The study provides percentage reduction in fire resistance under each case for the most commonly used cases in practice under different load conditions.

Originality/value

Extensive literature search has been performed by the authors, and few studies were found relevant to the topic. The question this study answers comes up regularly in practice. There are no standards to codes that address this issue.

Details

Journal of Structural Fire Engineering, vol. 10 no. 2
Type: Research Article
ISSN: 2040-2317

Keywords

Article
Publication date: 1 January 1940

Leslie P. Dudley

ALTHOUGH it is common knowledge that a steel beam may be replaced by a geometrically similar duralumin beam, with a resultant saving in weight, it is not so generally known that…

Abstract

ALTHOUGH it is common knowledge that a steel beam may be replaced by a geometrically similar duralumin beam, with a resultant saving in weight, it is not so generally known that such a procedure invariably involves the use of an unnecessarily large quantity of the light‐alloy, and is, therefore, wasteful. The reason for this is that adherence to geometrical similarity, when changing from steel to duralumin, accords the same proportional increase in thickness to all parts of the beam, thus giving uneconomical distribution of metal. It seems, therefore, that some notes showing how more efficient metal distribution may be achieved by departure from geometrical similarity may perhaps prove of interest.

Details

Aircraft Engineering and Aerospace Technology, vol. 12 no. 1
Type: Research Article
ISSN: 0002-2667

Article
Publication date: 11 July 2022

Xiaomin Zhao, Fuminobu Ozaki, Takeo Hirashima, Kei Kimura, Yukio Murakami, Jun-ichi Suzuki and Naoya Yotsumoto

The main purpose of this study was to propose theoretical calculation models to evaluate the theoretical bending strengths of welded wide-flange section steel beams with local…

Abstract

Purpose

The main purpose of this study was to propose theoretical calculation models to evaluate the theoretical bending strengths of welded wide-flange section steel beams with local buckling at elevated temperatures.

Design/methodology/approach

Steady-state tests using various test parameters, including width-thickness ratios (Class 2–4) and specimen temperatures (ambient temperature, 400, 500, 600, 700, and 800°C), were performed on 18 steel beam specimens using roller supports to examine the maximum bending moment and bending strength after local buckling. A detailed calculation model (DCM) based on the equilibrium of the axial force in the cross-section and a simple calculation model (SCM) for a practical fire-resistant design were proposed. The validity of the calculation models was verified using the bending test results.

Findings

The strain concentration at the local buckling cross-section was mitigated in the elevated-temperature region, resulting in a small bending moment degradation after local buckling. The theoretical bending strengths after local buckling, evaluated from the calculation models, were in good agreement with the test results at elevated temperatures.

Originality/value

The effect of local buckling on the bending behaviour after the maximum bending strength in high-temperature regions was quantified. Two types of calculation models were proposed to evaluate the theoretical bending strength after local buckling.

Details

Journal of Structural Fire Engineering, vol. 14 no. 2
Type: Research Article
ISSN: 2040-2317

Keywords

Article
Publication date: 8 July 2019

Ahmed Allam, Ayman Nassif and Ali Nadjai

This paper aims to investigate computationally and analytically how different levels of restraint from surrounding structure, via catenary action in beams, affect the survival of…

Abstract

Purpose

This paper aims to investigate computationally and analytically how different levels of restraint from surrounding structure, via catenary action in beams, affect the survival of steel framed structures in fire. This study focuses on examining the mid-span deflection and the tensile axial force of a non-composite heated steel beam at large deflection that is induced by the catenary action during exposure to fires. The study also considers the effect of the axial horizontal restraints, load-ratio, beam temperature gradient and the span/depth ratio. It was found that these factors influence the heated steel beam within steel construction and its catenary action at large deflection. The study suggests that this may help the beam to hang to the surrounding cold structure and delay the run-away deflection when the tensile axial force of the beam has been overcome.

Design/methodology/approach

This paper is part one of the parametric study and discusses both the effect of the axial horizontal restraints and load-ratio on the heated steel-beam. Reliance on the prescriptive standard fire solutions may lead to an unpredicted behaviour of the structure members if the impact of potential real fires is not considered.

Findings

Variation of the horizontal end-restraint level has a major effect on the behaviour of the beam at high deflection, and the loading on a beam at large displacement can be carried effectively by catenary behaviour. An increase of axial horizontal stiffness helps the catenary action to prevent run-away at lower deflections. The studies also investigated the influence of varying the load ratio on the behaviour of the heated beam at large deflection and how it affects the efficacy of the catenary action. The study suggests that care should be taken when selecting the load ratio to be used in the design.

Originality/value

In a recent work, the large deflection behaviours of axially restrained corrugated web steel beam (CWSB) at elevated temperatures were investigated using a finite element method (Wang et al., 2014). Parameters that greatly affected behaviours of CWSB at elevated temperatures were the load ratio, the axial restraint stiffness ratio and the span–depth ratio. Other works included numerical studies on large deflection behaviours of restrained castellated steel beams in a fire where the impact of the catenary action is considered (Wang, 2002). The impact of the induced axial forces in the steel beam during cooling stage of a fire when the beam temperature decreases, if thermal shortening of the beam is restrained, large tensile forces may be induced in the beam (Wang, 2005; Allam et al., 2002). A performance-based approach is developed for assessing the fire resistance of restrained beams. The approach is based on equilibrium and compatibility principles, takes into consideration the influence of many factors, including fire scenario, end restraints, thermal gradient, load level and failure criteria, in evaluating fire resistance (Dwaikat and Kodur, 2011; Allam et al., 1998).

Details

Journal of Structural Fire Engineering, vol. 10 no. 3
Type: Research Article
ISSN: 2040-2317

Keywords

Article
Publication date: 15 May 2018

Osama A.B. Hassan and Christopher Johansson

This paper aims to compare glued laminated timber and steel beams with respect to structural design, manufacturing and assembly costs and the amount of greenhouse gas emissions.

1324

Abstract

Purpose

This paper aims to compare glued laminated timber and steel beams with respect to structural design, manufacturing and assembly costs and the amount of greenhouse gas emissions.

Design/methodology/approach

This paper presents structural design requirements in conformance with EN 1993: Eurocode 5 and Eurocode 3. With the help of these standards, expressions are derived to evaluate the design criteria of the beams. Based on the results of life-cycle analysis, the economic properties and environmental impact of the two types of beam are investigated. In this paper, the effect of beam span on the design values, costs and carbon dioxide emissions is analysed when investigating aspects of the structural design, economy and environmental impact. Different cross-sections are chosen for this purpose.

Findings

The study shows that the glued laminated (abbreviated as “glulam”) beams have a smaller tendency to lateral torsional buckling than the steel beams, and that they can be cheaper. From an environmental point of view, glulam beams are the more environmentally friendly option of the two beam materials. Furthermore, glulam beams may have a direct positive effect on the environment, considering the carbon storage capacity of the wood. The disadvantage of glued wood is that larger dimensions are sometimes required.

Research limitations/implications

Wind load and the effect of second-order effects have not been considered when analysing the static design. Only straight beams have been studied. Furthermore, the dynamic design of the beams has not been investigated, and the bearing pressure capacity of the supports has not been analyzed. We have investigated timber beams with a rectangular cross-section, and steel beams of rolled I-sections, known as “HEA profiles”. The cost analysis is based mainly on the manufacturing and assembly costs prevalent on the Swedish market. The only environmental impact investigated has been the emission of greenhouse gases. The design calculations are based on the European standards Eurocode 5 and Eurocode 3.

Practical implications

To achieve sustainability in construction engineering, it is important to study the environmental and economic consequences of the building elements. By combining these two effects with the technical design of buildings made of steel and/or timber, the concept of sustainable development can be achieved in the long run.

Social implications

The study concerns sustainability of building structures, which is an important of the sustainable development of the society.

Originality/value

The paper contains new information and will be useful to researchers and civil engineers.

Details

Journal of Engineering, Design and Technology, vol. 16 no. 3
Type: Research Article
ISSN: 1726-0531

Keywords

Article
Publication date: 20 December 2023

Lifeng Wang, Jiwei Bi, Long Liu and Ziwang Xiao

This paper presents the experimental and numerical results of the bending properties of low-height prestressed T-beams. The purpose is to study the bearing capacity, failure state…

Abstract

Purpose

This paper presents the experimental and numerical results of the bending properties of low-height prestressed T-beams. The purpose is to study the bearing capacity, failure state and strain distribution of low-height prestressed T-beams.

Design/methodology/approach

First, two 13 m-long full-size test beams were fabricated with different positions of prestressed steel bundles in the span. The load–deflection curves and failure patterns of each test beam were obtained through static load tests. Secondly, the test data were used to validate the finite element model developed to simulate the flexural behavior of low-height prestressed T-beams. Finally, the influence of different parameters (the number of prestressed steel bundles, initial prestress and concrete strength grade) on the flexural performance of the test beams is studied by using a finite element model.

Findings

The test results show that when the distance of the prestressed steel beam from the bottom height of the test beam increases from 40 to 120 mm, the cracking load of the test beam decreases from 550.00 to 450.00 kN, reducing by 18.18%, and the ultimate load decreases from 1338.15 to 1227.66 kN, reducing by 8.26%, therefore, the increase of the height of the prestressed steel beam reduces the bearing capacity of the test beam. The numerical simulation results show that when the number of steel bundles increases from 2 to 9, the cracking load increases by 183.60%, the yield load increases by 117.71% and the ultimate load increases by 132.95%. Therefore, the increase in the number of prestressed steel bundles can increase the cracking load, yield load and ultimate load of the test beam. When the initial prestress is from 695 to 1,395 MPa, the cracking load increases by 69.20%, the yield load of the bottom reinforcement increases by 31.61% and the ultimate load increases by 3.97%. Therefore, increasing the initial prestress can increase the cracking load and yield load of the test beam, but it has little effect on the ultimate load. The strength grade of concrete increases from C30 to C80, the cracking load is about 455.00 kN, the yield load is about 850.00 kN and the ultimate load is increased by 4.90%. Therefore, the improvement in concrete strength grade has little influence on the bearing capacity of the test beam.

Originality/value

Based on the experimental study, the bearing capacity of low-height prestressed T-beams with different prestressed steel beam heights is calculated by finite element simulation, and the influence of different parameters on the bearing capacity is discussed. This method not only ensures the accuracy of bearing capacity assessment, but also does not require a large number of samples and has a certain economy. The study of prestressed low-height T-beams is of great significance for understanding the principle and application of prestressed technology. Research on the mechanical behavior and performance of low-height prestressed T beams can provide a scientific basis and technical support for the design and construction of prestressed concrete structures. In addition, the study of prestressed low-height T-beams can also provide a reference for the optimization design and construction of other structural types.

Details

International Journal of Structural Integrity, vol. 15 no. 1
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 1 October 2018

Amr M.I. Sweedan, Hothifa N. Rojob and Khaled M. El-Sawy

The purpose of this paper is to introduce a closed-form analytical solution to evaluate the nominal moment capacity and associated deflections of steel-FRP beam systems. The…

Abstract

Purpose

The purpose of this paper is to introduce a closed-form analytical solution to evaluate the nominal moment capacity and associated deflections of steel-FRP beam systems. The proposed solution takes into consideration the partial composite behavior resulting from the interfacial contact and slip between the subcomponents of the system.

Design/methodology/approach

The partial composite action theory was used to develop an elastic analytical solution for the deflection of simply supported composite steel-FRP beams subjected to a mid-span point load. The solution takes into consideration the partial composite behavior of the system that arises from the interlayer slip at the steel-FRP interface.

Findings

The developed analytical model is used to predict the nominal moment capacity of the composite beam and the load value at the onset of yielding in the steel subcomponent of the section. The distribution of shear forces induced in the steel fasteners due to the interfacial slip is also obtained analytically. A comparative study is conducted by comparing the analytical results to their counterparts resulting from finite element modeling of the composite steel-FRP system. The agreement between analytical results and finite element predictions validates the accuracy of the derived analytical solution for partial composite steel-FRP beams.

Research limitations/implications

The proposed solution applies only to the FRP strips and 6 mm steel bolts used in the study.

Originality/value

Recent studies revealed a promising efficiency of using mechanically fastened hybrid FRP sheets in strengthening steel beams. A major advantage of this technique is the ductile behavior of the steel-FRP system. The current paper introduces a closed-form analytical solution to evaluate the nominal moment capacity and associated deflections of steel-FRP beam systems. Forces developed at the steel-FRP interface due to the relative slip between both components are considered in the proposed analytical solution.

Details

International Journal of Structural Integrity, vol. 9 no. 5
Type: Research Article
ISSN: 1757-9864

Keywords

1 – 10 of over 4000