scholarly journals DEVELOPMENT OF AN OPTIMUM PRE-FOUNDED COLUMN SYSTEM FOR TOP-DOWN CONSTRUCTION

2012 ◽  
Vol 18 (5) ◽  
pp. 735-743 ◽  
Author(s):  
Hong-Chul Rhim ◽  
Kyung-Min Kim ◽  
Seung-Weon Kim
Keyword(s):  
Test Results ◽  
Top Down ◽  
Construction Costs ◽  
Shear Connectors ◽  
Shear Connection ◽  
Flat Slabs ◽  
Column System ◽  
Connection System ◽  
Headed Stud

In this work, circular concrete-filled steel tubular (CCFT) columns, rather than the more popular H-shaped columns, were suggested as pre-founded columns for top-down construction. In addition, a novel shear connection system with headed stud shear connectors between the CCFT columns and the flat slabs was developed. It was noted that a CCFT column with a design compressive strength similar to that of an H-shaped column without consideration of length effects can be easily installed, even into a smaller borehole. Furthermore, compared to the H-shaped column, less steel is required for the CCFT column. It was shown that the amount of steel needed can be reduced by decreasing the wall thicknesses or diameters of the CCFT column depending on the exposed length of the column during excavation. The fillet-welded joint of the developed shear connector system was also tested before its in-situ application. The test results revealed that the joint possessed sufficient shear and deformation capacities. The CCFT column with the developed shear connection system was ultimately applied to an actual top-down construction process. The good constructability of the CCFT column system and reductions in construction costs and time were confirmed.

Reliability analysis of shear connection in composite beams with profiled steel sheeting

2011 ◽  
Vol 8 (1) ◽  
pp. 29-34
Author(s):  
M. Youcef ◽  
M. Mimoune ◽  
F. Mimoune
Keyword(s):  
Reliability Analysis ◽  
Failure Modes ◽  
Composite Beams ◽  
Steel Beam ◽  
British Standard ◽  
Shear Connectors ◽  
Shear Connection ◽  
Composite Slabs ◽  
European Code ◽  
Headed Stud

This paper describes the reliability analysis of shear connection in composite beams with profiled steel sheeting. The profiled steel sheeting had transverse ribs perpendicular to the steel beam. The level of safety of shear connection, and failure modes were determinate. An extensive parametric study was conducted to study the effects on the safety and behaviour of shear connection by changing the profiled steel sheeting geometries, the diameter and height of headed stud, as well as the strength of concrete. We compared the level safety calculated using the American specification, British standard and European code for headed stud shear connectors in composite slabs with profiled steel sheeting perpendicular to the steel beam. It is found that the design overestimated the level safety of shear connection.

ESTIMATION OF THE POWDER-ACTUATED SHEAR CONNECTORS TESTS

2021 ◽  
Vol 295 (2) ◽  
pp. 16-26
Author(s):  
D.V. Konin ◽  
Keyword(s):  
Bearing Capacity ◽  
Estimation Methods ◽  
Shear Connector ◽  
Connection Strength ◽  
Test Results ◽  
European Standard ◽  
Design Code ◽  
Shear Connectors ◽  
Shear Connection

The shear connector design should be executed according to the SP 266.1325800.2016. For the different typed of welded connectors are there analytic dependences, which could be used for shear connection strength estimation. The design code also allows to use powder-actuated Z-shape shear connectors. Their bearing capacity should be proved by tests according to the GOST R 58336-2018. Inasmuch the GOST doesn't consist the test estimation approach, the authors offer the method. For the test estimation methods the test results of 15 series specimen had been used. The results were compared with estimation according to the European standard for the verification.

FEASIBILITY OF USING BOLTED SHEAR CONNECTOR WITH COLD-FORMED STEEL IN COMPOSITE CONSTRUCTION

2016 ◽  
Vol 78 (6-12) ◽  
Author(s):  
Mustapha Muhammad Lawan ◽  
Mahmood Md. Tahir ◽  
Emad Hosseinpour
Keyword(s):  
Shear Connector ◽  
Test Results ◽  
Composite Construction ◽  
Composite Action ◽  
Shear Connectors ◽  
Shear Connection ◽  
Cold Formed Steel ◽  
Hot Rolled ◽  
Hot Rolled Steel ◽  
Push Out

In conventional composite construction for hot-rolled steel (HRS) section, the composite action is usually achieved by using headed studs shear connectors. But, for cold-formed steel (CFS) section, the use of headed studs is not feasible as the section is very thin and difficult to be weld.  Therefore, an innovative way of shear connection mechanism of using bolt and nut is suggested in this study. This paper presents the feasibility of using bolt as shear connector by presenting experimental test results so as to explore more on their capability to be used as shear connectors. The study investigated the structural capability of the proposed bolted shear connector when used in concrete known as Self-compacting concrete (SCC) integrated with CFS to provide the required composite action. Push out test specimens with bolted shear connector of grade 8.8 at designated intervals longitudinally spaced were fabricated, cast and tested to failure. The results showed that the proposed shear connector was structurally capable and also an appreciable strength resistance was achieved. 

scholarly journals Experimental Study on a Novel Shear Connection System for FRP-Concrete Hybrid Bridge Girder

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2045 ◽  
Author(s):  
Mateusz Rajchel ◽  
Maciej Kulpa ◽  
Tomasz Siwowski
Keyword(s):  
Fatigue Strength ◽  
Adhesive Bonding ◽  
Laminated Composite ◽  
Shear Capacity ◽  
The Novel ◽  
Shear Connectors ◽  
Shear Connection ◽  
Hybrid Bridge ◽  
Connection System ◽  
Reliability And Robustness

The study presents experimental results of an investigation on a novel shear connection system for hybrid bridge girders composed of laminated composite beams and concrete slabs. The special connector comprised of a steel plate and welded bolts is attached to beam’s top flange by adhesive bonding and with a preset torque of nuts. The study’s purpose is to check ductility, safety, reliability and robustness of the shear connection before its implementation in the first Polish composite bridge. Three static push-out tests and fatigue test were performed to evaluate the shear connection behavior under static and cyclic loading. The load–slip curves, shear capacity, fatigue strength and failure mechanisms of the novel shear connectors are discussed. The high-slip modulus indicates that the connectors can very efficiently promote the composite action. The ultimate resistance and the fatigue strength obtained from the test was about 12% and 66% higher than the characteristic resistance and the fatigue strength of common headed studs, according to Eurocode 4, respectively. An estimated global safety factor of 3.67 showed the high safety, reliability and robustness of the novel connection system. The study discusses the structural performance of the proposed connection system, demonstrating its technical suitability.

A parametric study of perfobond rib shear connectors

1994 ◽  
Vol 21 (4) ◽  
pp. 614-625 ◽  
Author(s):  
E. C. Oguejiofor ◽  
M. U. Hosain
Keyword(s):  
Compressive Strength ◽  
Shear Capacity ◽  
Transverse Reinforcement ◽  
Shear Connectors ◽  
Shear Connection ◽  
New Type ◽  
Flat Steel ◽  
Compressive Strength Of Concrete ◽  
Headed Stud ◽  
Push Out

This paper summarizes the results of 40 push-out test specimens with a new type of shear connector called perfobond rib. This connector is a flat steel plate with a number of holes punched through. The test specimens were designed to study the effect of a number of parameters on the shear capacity of the connection. These were the number and spacing of rib holes, transverse reinforcement, and compressive strength of concrete. The main objective of this study was to derive an expression for predicting the capacity of perfobond rib connector based on the results of the parametric study.The test results indicate that the shear capacity of the perfobond rib connector increases with the number of rib holes as long as the hole spacing is at least 2.25 times the diameter of the holes. The effect of increasing the transverse reinforcement ratio from 0.27% to 0.36% was an increase of approximately 16% in the shear capacity of the connection. Similarly, an increase of 36% in the shear connection capacity was achieved due to a 63% increase in concrete strength.An expression for computing the shear capacity of perfobond rib connectors is proposed. A regression analysis, which is based on a model that takes into account the contributions of concrete dowels formed by the rib holes, the transverse reinforcement, and the strength of concrete, was used in the derivation. Key words: composite beam, perfobond rib connector, headed stud, push-out test, compressive strength of concrete, transverse reinforcement.

Numerical assessment of shear connection for steel and concrete composite floors

2019 ◽  
Author(s):  
Talita L. Silva ◽  
Isabel B. Valente
Keyword(s):  
Numerical Models ◽  
Concrete Slab ◽  
Shear Stresses ◽  
Shear Connectors ◽  
Shear Connection ◽  
Numerical Assessment ◽  
Connection System ◽  
Parametric Analyses ◽  
Push Out ◽  
Composite Floors

<p>The use of steel and concrete in composite floors contributes to more sustainable constructions, because they become lighter, the overall weight of the building is reduced and the steel components can act as formwork. Composite flooring solutions are usually composed by a composite concrete slab and a steel profile. This system is mechanically successful if shear connectors are used, as they guarantee the transmission of shear stresses between the steel and the concrete components. This investigation proposes the use of a connection system, composed by a ribbed steel plate welded to the profile and is embedded into the concrete slab after the concreting phase. The study was carried out through numerical modelling to represent a group of push-out tests previously performed. From the comparison with the experimental results, it was possible to calibrate the numerical models and developed parametric analyses.</p>

scholarly journals Experimental Investigation on Behavior of Composite Open Web Steel Joists

2018 ◽  
Vol 21 (3) ◽  
pp. 393-404
Author(s):  
Ali Farhan Hadeed ◽  
Laith Khalid Al-Hadithy ◽  
Riyadh J. Aziz
Keyword(s):  
Concrete Slab ◽  
Light Weight ◽  
Shear Connector ◽  
Test Results ◽  
Variable Parameters ◽  
Shear Connectors ◽  
Shear Connection ◽  
Strength Capacity ◽  
Floor Systems ◽  
The Web

The composite opened web steel joist supported floor systems have been common for many years. It is economic and has light weight and can embed the electrical conduit, ductwork and piping, eliminating the need for these to pass under the member, consequently eliminate the height between floors. In order to study the joist strength capacity under the various conditions, it had been fabricated seven joists composed of the steel and concrete slab connected to the top chord by shear connectors (headed studs). These joist have 2820 mm length c/c of the supports and 235 mm overall depth. In the present study, six variable parameters are adopted (Studs distribution, Degree of shear connection, Degree of the web inclination, Shape of the web, Density of concrete for slab and length of the shear connector). The test results exhibited that minimum strength capacity was 160kN for light weight joist and maximum capacity was 225kN for joist of long shear connectors at failure. The results were compared by ultimate flexural model by Azmi.

The strength of stud shear connectors at low temperatures

1983 ◽  
Vol 10 (3) ◽  
pp. 429-436 ◽  
Author(s):  
Karl Van Dalen
Keyword(s):  
Room Temperature ◽  
Concrete Slab ◽  
Concrete Strength ◽  
Normal Weight ◽  
Effect Of Temperature ◽  
Shear Connectors ◽  
Normal Weight Concrete ◽  
Shear Connection ◽  
Shear Connections ◽  
Headed Stud

The effect of temperature on the ultimate strength of shear connections consisting of headed stud shear connectors embedded in a normal weight concrete slab is examined by means of pushout tests conducted at temperatures of +20, −10, and −20 °C. The strength of the shear connection with 13 mm diameter studs was found to be lower at −20 °C than at room temperature, whereas the strength of the shear connection with 19 mm diameter studs was found to be greater at −20 °C than at room temperature. This is explained in terms of increased concrete strength and reduced stud strength with decreased temperature, causing a change in the mode of failure. Keywords: composite construction, shear strength, shear connection, stud shear connectors, low temperature pushout tests.

FIRE RESISTACE OF SHEAR CONNECTORS FOR COMPOSITE BEAMS

2020 ◽  
Vol 92 (6) ◽  
pp. 59-65
Author(s):  
G.P. TONKIH ◽  
◽  
D.A. CHESNOKOV ◽  
◽  
Keyword(s):  
Fire Resistance ◽  
Composite Structure ◽  
Composite Structures ◽  
Composite Beams ◽  
Design Codes ◽  
Connection Strength ◽  
Shear Connectors ◽  
Shear Connection ◽  
Capacity Reduction ◽  
Russian Research

Most of Russian research about composite structure fire resistance are dedicated to the composite slab behavior. The composite beams fire resistance had been never investigated in enough volume: the temperature evaluation within the scope of the actual Russian design codes leads to the significant reduction in the shear connection strength. Meanwhile, there no correlation between the strength decreasing and type of the shear connection. The article provides an overview of the relevant researches and offers some approaches which could take into account bearing capacity reduction of the shear connectors within composite structures design.

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