scholarly journals Flexural Design and Analysis of Composite Beams with Inverted-T Steel Girder with Ultrahigh Performance Concrete Slab

2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Wonchang Choi ◽  
Youngcheol Choi ◽  
Sung-Won Yoo

This study intends to improve the efficiency of the composite beam combining a slab made of steel fiber-reinforced ultrahigh performance concrete (UHPC) and a steel girder without top flange. To that goal, the experiment is conducted on 24 composite beams fabricated with varying compressive strength of UHPC, steel fiber content, stud spacing, and slab thickness to evaluate the behavior of the studs and the flexural behavior of the composite beam combining the UHPC slab and the inverted-T steel girder. The experimental results show the test members developed sufficient ductile behavior with respect to the slip limit of 6 mm stipulated in Eurocode-4 and regardless of the considered test variables. The experimental ultimate horizontal shear force is seen to be clearly larger than the static strengths of the stud predicted by Eurocode-4 and AASHTO-LRFD. Improved design formulae for the composite beam shall be derived to reflect the UHPC slab thickness.

2018 ◽  
Vol 28 (4) ◽  
pp. 149-162 ◽  
Author(s):  
Marcin Chybiński ◽  
Łukasz Polus

Abstract In this paper, the bending resistance of three metal-concrete composite beams was compared in real car fires in an open car park. Steel and concrete composite beams are often used for the construction of ceilings in multi-storey car parks. The authors made an attempt to evaluate how the replacement of a non-alloy steel girder with a stainless steel or aluminium alloy girder affects the bending resistance of a composite beam under fire conditions. The analysed beams were not fire-protected. They consisted of a concrete slab and a girder made of: non-alloy (carbon) S235J2 (1.0117) steel, X6CrNiMoTi17- 12-2 (1.4571) stainless steel, and AW-6061 T6 (EN AW-Al Mg1SiCu) aluminium alloy.


1976 ◽  
Vol 3 (4) ◽  
pp. 514-522 ◽  
Author(s):  
M. N. El-Ghazzi ◽  
H. Robinson ◽  
I. A. S. Elkholy

The longitudinal shear failure of the slab of composite beams is constrained to occur at a predetermined shear surface. A method for calculating the longitudinal shear capacity of the slab of simply-supported steel–concrete composite beams is presented. The method is based on analyzing the stresses at failure of the concrete elements located at the slab shear surface.A design chart based on estimating the transverse normal stress required within the concrete slab to achieve the full ultimate flexural capacity of the composite beam is proposed. Alternatively, using elastic–plastic stress distribution across the concrete slab, the longitudinal compressive force due to bending and hence the applied moment can be predicted for any longitudinal shear capacity of the slab. The proposed design and analysis when compared to previous tests and analysis showed good agreement.The slab width and the shear span of the composite beam are found to be two important parameters which cannot be neglected when estimating the longitudinal shear capacity of the slab. These two parameters have been neglected in the empirical solutions previously adopted.


2018 ◽  
Author(s):  
◽  
Ayman Elzohairy

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] The steel-concrete composite beam represents a structural system widely employed in both buildings and girder bridges. The coupling between steel beams and concrete flanges assures both economic and structural benefits because of quick construction of steel structures and large increase in stiffness due to the presence of concrete. Strengthening with external post-tensioning (PT) force is particularly effective and economical for long-span steel-concrete composite beams and has been employed with great success to increase the bending and shear resistance and correct excessive deflections. Applying external PT force to the steel-concrete composite beam is considered an active strengthening technique that can create permanent internal straining action in the beam which is opposite to the existing straining action due to the applied service loads. The most benefits of using this system of strengthening are an elastic performance to higher loads, higher ultimate capacity, and reduction in deformation under the applied loads. Under service loads, bridge superstructures are subjected to cyclic loads which may cause a premature failure due to fatigue. Therefore, fatigue testing is critical to evaluate existing design methods of steel-concrete composite beams. ... This research presents static and fatigue tests on four steel-concrete composite specimens to evaluate the effect of externally post-tensioned tendons on the ultimate strength and fatigue behavior of composite beams. Fatigue tests are conducted to a million cycles under a four-point bending test. In addition, final static tests are performed on fatigued specimens to evaluate the residual strength of the strengthened specimen. A numerical model is described to predict the fatigue response of the composite beam by considering the fatigue damage in the concrete flange. The accuracy of the developed numerical model is validated using the existing test data. The static test results indicate that the external post-tensioning force improves the flexural behavior of the strengthened specimen by increasing the beam capacity and reducing the tensile stress in the bottom flange of the steel beam. The fatigue results demonstrate that the external post-tensioning significantly decreases the strains in the shear connectors, concrete flange, and steel beam. The tendons demonstrated an excellent fatigue performance, with no indication of distress at the anchors.


2020 ◽  
Vol 2020 ◽  
pp. 1-17 ◽  
Author(s):  
Boxin Wang ◽  
Ruichang Fang ◽  
Qing Wang

Given the excellent crack resistance performance of steel fiber-reinforced self-stressing concrete (SFRSSC), the bending performance of some composite beams with SFRSSC laminated layers was studied. The experiment conducted in this study comprised a single-span composite beam test (including 3 test beams) and a two-span continuous composite beam test (including 2 test beams). All the test beams were T-shaped. The cracking load, yielding load, and ultimate load of all the test beams were recorded and comparatively analyzed. Experimental results showed that the cracking load of the test beam with an SFRSSC laminated layer is significantly increased. Mechanical analysis and numerical simulation of the test beams were conducted, and the obtained results agreed well with the experimental results. The composite beams under different working conditions were also numerically simulated. Through the simulation, reasonable ranges of precompressive stress and length of the SFRSSC laminated layer at intermediate support of continuous composite beam were obtained.


2019 ◽  
Vol 10 (4) ◽  
pp. 411-434 ◽  
Author(s):  
Mohammad Hajjar ◽  
Elie Hantouche ◽  
Ahmad El Ghor

Purpose This study aims to develop a rational model to predict the thermal axial forces developed in shear tab connections with composite beams when subjected to transient-state fire temperatures. Design/methodology/approach Finite element (FE) models are first developed in ABAQUS and validated against experimental data available in the literature. Second, a parametric study is conducted to identify the major parameters that affect the behavior of shear tab connections with composite beams in the fire. This includes beam length, shear tab thickness, shear tab location, concrete slab thickness, setback distance and partial composite action. A design-oriented model is developed to predict the thermal induced axial forces during the heating and cooling phases of a fire event. The model consists of multi-linear springs that can predict the stiffness and strength of each component of the connection with the composite beam. Findings The FE results show that significant thermal axial forces are generated in the composite beam in the fire. This is prominent when the beam bottom flange comes in contact with the column. Fracture at the toe of the welds governs the behavior during the cooling phase in most FE simulations. Also, the rational model is validated against the FE results and is capable of predicting the thermal axial forces developed in shear tab connections with composite beams under different geometrical properties. Originality/value The proposed model can predict the thermal axial force demand and can be used in performance-based approaches in future structural fire engineering applications.


2016 ◽  
Vol 7 (2) ◽  
pp. 142-157 ◽  
Author(s):  
Kristi L. Selden ◽  
Amit H. Varma

Purpose The purpose of this study was to develop a three-dimensional (3D) finite element modeling (FEM) technique using the commercially available program ABAQUS to predict the thermal and structural behavior of composite beams under fire loading. Design/methodology/approach The model was benchmarked using experimental test data, and it accounts for temperature-dependent material properties, force-slip-temperature relationship for the shear studs and concrete cracking. Findings It was determined that composite beams can be modeled with this sequentially coupled thermal-structural 3D FEM to predict the displacement versus bottom flange temperature response and associated composite beam failure modes, including compression failure in the concrete slab, runaway deflection because of yielding of the steel beam or fracture of the shear studs. Originality/value The Eurocode stress-strain-temperature (σ-ε-T) material model for structural steel and concrete conservatively predict the composite beam deflections at temperatures above 500°C. Models that use the National Institute of Standards and Technology (NIST) stress-strain-temperature (σ-ε-T) material model more closely match the measured deflection response, as compared to the results using the Eurocode model. However, in some cases, the NIST model underestimates the composite beam deflections at temperatures above 500°C.


2018 ◽  
Vol 7 (3.10) ◽  
pp. 54
Author(s):  
T Subramani ◽  
A Periasamy

Composite plays a vital role in replacing the existing mild steel in reinforcement and exterior truss structure. This study proposed to design shear connector for joining concrete slab and steel section. Shear connectors has analyzed and predict the best connector for a particular composite beam with respect to static load and the amount of steel in the connector as a common aspect. The use of composite structures is increasingly present in civil construction works nowadays. Composite beams, especially, are structures which include substances, a metal phase placed in particular inside the tension region and a concrete phase, positioned in the compression go sectional location, both are related with the aid of steel gadgets called shear connectors. The main features of this connector are to permit the weight for the joint the beam-column, to restriction longitudinal slipping and uplifting on the factors interface the shear forces. Our project paper presents 3D numerical models of steel-concrete composite beams to simulate their structural behaviour, with emphasis on the beam column interface using Simulations software ANSYS 18.1 based on the Finite Element Method. Mostly these type of structures are widely used in the dynamic loading structures like bridges and high rise buildings.  


Author(s):  
Balbir Singh ◽  
Ee Loon Tan ◽  
Zhu Pan ◽  
Olivia Mirza ◽  
Julius Boncato

To combat the present situation of greenhouse gases emission from cement production, a promising solution is to utilise supplementary cementitious by-product materials such as fly ash to produce green concrete known as Geopolymer concrete (GPC). However, despite fly ash based concrete is a promising substitute for ordinary Portland cement (OPC) concrete, it is not yet being utilised to its full potential for structural applications.  And so, to utilise green concrete to its full potential, this paper aim is to conduct an experimental study that will integrate fly ash based concrete within steel-concrete composite beams. The research will include casting of composite beams with GPC mix, and an OPC concrete as a reference mix designed according to British Standards. To determine the ultimate moment capacity, a total of Four (4) composite beams comprised of coventional and Bondek steel profile concrete slab are designed and tested according to Australian Standards. From the test results, it was found that composite beam with conventionalconcrete slab outperformed the beams with Bondek profile sheeting. Also, regarding of ultimate bending moment capacity, the composite beam with geopolymer concrete experienced almost identical to OPC composite beam.


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