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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…

2551

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…

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…

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…

150

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…

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…

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. ahead-of-print no. ahead-of-print
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…

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.

1071

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: 10 December 2021

Long Liu, Lifeng Wang and Ziwang Xiao

Reinforcement of reinforced concrete (RC) beams in-service have always been an important research field, anchoring steel plate in the bottom of the beams is a kind of…

Abstract

Purpose

Reinforcement of reinforced concrete (RC) beams in-service have always been an important research field, anchoring steel plate in the bottom of the beams is a kind of common reinforcement methods. In actual engineering, the contribution of pavement layer to the bearing capacity of RC beams is often ignored, which underestimates the bearing capacity and stiffness of RC beams to a certain extent. The purpose of this paper is to study the effect of pavement layer on the RC beams before and after reinforcement.

Design/methodology/approach

First, static load experiments are carried out on three in-service RC hollow slab beams, meanwhile, nonlinear finite element models are built to study the bearing capacity of them. The nonlinear material and shear slip effect of studs are considered in the models. Second, the finite element models are verified, and the numerical simulation results are in good agreement with the experimental results. Last, the finite element models are adopted to carry out the research on the influence of different steel plate thicknesses on the flexural bearing capacity and ductility.

Findings

The experimental results showed that pavement layers increase the flexural capacity of hollow slab beams by 16.7%, and contribute to increasing stiffness. Ductility ratio of SPRCB3 and PRCB2 was 30% and 24% lower than that of RCB1, respectively. The results showed that when the steel plate thickness was 1 mm–6 mm, the bearing capacity of the hollow slab beam increased gradually from 2158.0 kN.m to 2656.6 kN.m. As the steel plate thickness continuously increased to 8 mm, the ultimate bearing capacity increased to 2681.0 kN.m. The increased thickness did not cause difference to the bearing capacity, because of concrete crushing at the upper edge.

Originality/value

In this paper, based on the experimental study, the bearing capacity of hollow beam strengthened by steel plate with different thickness is extrapolated by finite element simulation, and its influence on ductility is discussed. This method not only guarantees the accuracy of the bearing capacity evaluation, but also does not require a large number of samples, and has certain economy. The research results provide a basis for the reinforcement design of similar bridges.

Details

Multidiscipline Modeling in Materials and Structures, vol. 18 no. 1
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 3 August 2021

Long Liu, Lifeng Wang and Ziwang Xiao

The flexural reinforcement of bridges in-service has been an important research field for a long time. Anchoring steel plate at the bottom of beam is a simple and…

Abstract

Purpose

The flexural reinforcement of bridges in-service has been an important research field for a long time. Anchoring steel plate at the bottom of beam is a simple and effective method to improve its bearing capacity. The purpose of this paper is to explore the influence of anchoring steel plates of different thicknesses on the bearing capacity of hollow slab beam and to judge its working status.

Design/methodology/approach

First, static load experiments are carried out on two in-service RC hollow slab beams; meanwhile, nonlinear finite element models are built to study the bearing capacity of them. The nonlinear material and shear slip effect of studs are considered in the models. Second, the finite element models are verified, and the numerical simulation results are in good agreement with the experimental results. Finally, the finite element models are adopted to carry out the research on the influence of different steel plate thicknesses on the flexural bearing capacity and ductility.

Findings

When steel plates of different thicknesses are adopted to reinforce RC hollow slab beams, the bearing capacity increases with the increase of the steel plate thickness in a certain range. But when the steel plate thickness reaches a certain level, bearing capacity is no longer influenced. The displacement ductility coefficient decreases with the increase of steel plate thickness.

Originality/value

Based on experimental study, this paper makes an extrapolation analysis of the bearing capacity of hollow slab beams reinforced with steel plates of different thicknesses through finite element simulation and discusses the influence on ductility. This method not only ensures the accuracy of bearing capacity evaluation but also does not need many samples, which is economical to a certain extent. The research results provide a basis for the reinforcement design of similar bridges.

Details

International Journal of Structural Integrity, vol. 12 no. 4
Type: Research Article
ISSN: 1757-9864

Keywords

1 – 10 of over 4000