Push-out tests of shear connectors for new fully assembled steel- concrete composite beams

Author(s):  
Hetao Hou ◽  
Ning Wang ◽  
Zengyun Zang

<p>To accomplish rapid installation and replaceability, a new type of connector for new fully assembled steel-concrete composite beams was studied. The connectors are fixed on the C-shaped channels of the prefabricated floor slab. The load transfer along the interface of the precast floor slab and the steel beam is primarily achieved through the friction between the beam flange and the channels. Push-out tests were conducted to study the mechanical properties of new composite beam. The effects of different C-shaped channel types, repeated loading and number of connectors were investigated. Test results showed that all the connectors exhibited satisfactory performance. When the section height of C-shaped channel is small, the restraining effect on the connector is more remarkable. The shear strength and shear stiffness of the connectors can be improved by reloading. The formulas for calculating the shear strength derived agree well with the experimental results.</p>

2011 ◽  
Vol 243-249 ◽  
pp. 1497-1503
Author(s):  
Qing Tian Su ◽  
Dong Fang Wang

Connectors are the key element in steel and concrete composite structure. To research and develop new type connector for steel and concrete composite structure, a new type connector, corrugated rib connector, was developed. The base mechanical properties of this connector were tested by push-out tests. The test results shown the mechanical properties of this connector are excellent. Comparing to the push-out test results of perfobond rib connector, the shear strength of corrugated rib connector increased 24 percent than that of the perfobond rib connector, and the shear stiffness of corrugated rib connector is larger than that of the perfobond rib connector, Especially the ductility of corrugated rib connector is 1.9 times that of the perfobond rib connector when they reach the ultimate load. Based on the load-slip relation of corrugated rib connector by push-out tests, relative stiffness expressions under normal service state and ultimate bearing capacity state are obtained.


Author(s):  
Zhanchong Shi ◽  
Qingtian Su ◽  
Xinyi He ◽  
Quanlu Wang ◽  
Kege Zhou ◽  
...  

<p>In order to solve the construction problem of perforating rebars’ precise location and it’s getting through the circular holes for the the conventional perfobond connector, a new type of perfobond connector with boot shaped slots was proposed. This new type perfobond connector has the advantage of convenient construction and pricise location. Three groups of push-out tests with nine specimens were carried out to study the shear capacity of the new type perfobond connector. The effect of the number and the spacing of boot shaped slots on failure modes, shear capacity, peak slip and shear stiffness were mainly studied. The test results show that the new type of perfobond connector with boot shaped slots has a high shear capacity and a good ductility, it could be widely applied on the connection between the steel and the concrete structures.</p>


2018 ◽  
Vol 22 (1) ◽  
pp. 202-213 ◽  
Author(s):  
Xizhi Wang ◽  
Yuqing Liu ◽  
Yangqing Liu

It is restricted in applying perfobond connectors in steel-concrete composite bridges with shallow rib heights or narrow connector distances, because it is unfavorable to enhance shear connection by enlarging hole diameter of perfobond connectors and difficult to install transverse rebars in perforated holes. To address this issue, an alternative perfobond connector was proposed by making a notch on the outer edge of the lengthened circular hole in this paper. To investigate the differences of failure mode, shear strength, slip behavior, and load transferring mechanism between circular-hole and notched long-hole perfobond connectors, a total of eight push-out tests were performed. Experimental results show that the shear strength of notched long-hole perfobond connectors exhibits an increase of about 20% compared with that of circular-hole perfobond connectors, and the shear stiffness and peak slip increase by over 10%. The enlarged hole area in notched long-hole perfobond connectors could weaken contribution percentage of concrete dowel to shear capacities, although the shear strength increases as the product of concrete compressive strength and hole area raises. Repeated loading hardly impacts shear strength of perfobond connectors but raises peak slip by 11% and 14% of circular-hole and notched long-hole perfobond connectors, respectively. Compared with single-row connectors, multi-row connectors exhibit a reduction of about 5% in shear capacities and an increase of about 10% in peak slips. The first row along the shear direction in multi-row connectors would bear the maximum percentage of shear load. Based on push-out test results, several typical existing equations for predictions of shear strength are compared and evaluated.


2018 ◽  
Vol 11 (5) ◽  
pp. 960-965
Author(s):  
O. P. AGUIAR ◽  
R. B. CALDAS ◽  
F. C. RODRIGUES ◽  
R. H. FAKURY ◽  
G. S. VERÍSSIMO

Abstract This paper presents an experimental study with numerical modeling of Crestbond shear connectors in concrete filled tube columns. The Crestbond, which consists in a steel plate with regular cuttings, was originally conceived for composite beams and is now being proposed as an alternative device for load introduction and shear transfer at the steel-concrete interface in concrete filled tube columns. The results achieved in this work were very favorable to the new application proposed for the connector as high values of shear strength were obtained. Moreover, the numerical and experimental results enabled comparative analysis and investigations regarding the influence of concrete conditions and the geometry of the column section on the mechanical properties of the connector.


2014 ◽  
Vol 578-579 ◽  
pp. 196-200
Author(s):  
Jian Sheng Fan ◽  
Wen Liu

Push-out tests were conducted to study the performance of shear studs in composite beams with profiled sheeting. All stud specimens were through-deck welded on steel beams. Three variables, i.e. the presence of profiled sheeting, the direction of the steel sheeting and the loading patterns were studied. Comparison between test results and predictions according to design specifications were also proposed. The research shows that, direction of the profiled steel sheeting has little influence on the ultimate load with shank shearing failure; shear failure of concrete rib decreases the shear strength; and the shear resistance of a parallel concrete rib is about twice of a transverse one.


Author(s):  
Mohammed Abdulhussein Al-Shuwaili ◽  
Alessandro Palmeri ◽  
Maria Teresa Lombardo

Push-out tests (POTs) have been widely exploited as an alternative to the more expensive full-scale bending tests to characterize the behaviour of shear connections in steel-concrete composite beams. In these tests, two concrete slabs are typically attached to a steel section with the connectors under investigation, which are then subjected to direct shear. The results allow quantifying the relationship between applied load and displacements at the steel-concrete interface. Since this relationship is highly influenced by the boundary conditions of POT samples, different experimental setups have been used, where the slabs are either restricted or free to slide horizontally, as researchers have tried to reduce any discrepancy between POT and full-scale composite beam testing. Based on a critical review of various POT configurations presented in the dedicated literature, this paper presents an efficient one-sided POT (OSPOT) method. While OSPOT and POT specimens are similar, in the proposed OPSPOT setup only one of the two slabs is directly loaded in each test, and the slab is free to move vertically. Thus, two results can be obtained from one specimen, i.e. one from each slab. A series of POTs and OSPOTs have been conducted to investigate the behaviour and the shear resistance of headed stud connectors through the two methods of testing. The results of this study than were compared with those of different POTs setups conducted by other researchers. The new OSPOT results show in general an excellent agreement with the analytical predictions offered by both British and European standards, as well as the estimated shear resistance proposed other researchers in the literature. These findings suggest that the proposed one-sided setup could be used as an efficient and economical option for conducting the POT, as it has the potential not only to double the number of results, but also to simplify the fabrication of the samples, which is important in any large experimental campaign, and to allow testing with limited capacity of the actuator. 


1975 ◽  
Vol 2 (1) ◽  
pp. 98-115
Author(s):  
A. E. Long ◽  
K. Van Dalen ◽  
P. Csagoly

The fatigue behavior of the negative moment region of continuous steel–concrete composite beams under Canadian temperature conditions was studied. Tests were conducted on three 26 ft 0 in. (7.92 m) long beams, continuous over a central support, and on 11 conventional push-out specimens. These were supplemented by a theoretical study of the internal forces in the beams using an iterative method of analysis.The close agreement between measured and theoretical strains and deflections indicated that good interaction was achieved throughout the length of the beams. The beams sustained 500 000 cycles of loading with no serious deterioration of composite action. The pattern of stud failures was consistent from beam to beam and reflected closely the calculated distribution of horizontal shear force at the steel–concrete interface. Stud shear connectors in the negative moment region where the slab had cracked in tension were found to be slightly less effective than studs in the positive bending moment regions.Neither the detailed study of individual connectors in the beams nor the results of the push-out tests show evidence of a reduction in the fatigue life of studs at −20 °F (−29 °C) relative to room temperature. The beams also exhibited no significant difference in their overall performance at these two temperatures.


2018 ◽  
Vol 26 (1) ◽  
pp. 9-18
Author(s):  
Dooyong Cho ◽  
Jinwoong Choi ◽  
Hoseong Jeong

When Perfobond Rib shear connectors are used as flexural materials in structures such as bridges, they show flexural shear behavior due to external force, rather than direct shear behavior. The aim of this study is thus to analyze the difference between both behaviors. First, we prepared a specimen to analyze direct shear behavior using Perfobond Rib shear connectors, analyzed the characteristics of behavior with a push-out test and proposed a formula of shear resistance assessment. Proposed formula shows a relatively good fit with less than 10% error. A flexural shear test was then conducted based on the result of the direct shear test. Based on the static flexural test it analyzed the flexural behavior and the flexural shear stress it calculated. Direct shear stress and EN 1994-1-1 to lead and be calculated, it compared the flexural shear stress and it analyzed in about the shear resistance stress which it follows in load direction. Finally, we compared both test results, and the comparison showed that the flexural shear stress is approximately 6% stronger than the direct shear stress.


2006 ◽  
Vol 326-328 ◽  
pp. 1811-1816 ◽  
Author(s):  
Young Ho Kim ◽  
Jae Ho Jung ◽  
Soon Jong Yoon ◽  
Won Sup Jang

In the construction of composite bridge structures, various types of shear connectors are usually used to provide an efficient load transfer and the composite action of two or more different materials. In the previous work conducted by authors, a new type of the shear connector was introduced, which is the perforated shear connector with flange heads (T-shaped perforated shear connector), and the structural behavior of the shear connector was discussed based on the results of push-out tests. For the practical design of new shear connector, it is necessary to develop the equation for the prediction of the load carrying capacity of the shear connector. In this study, the existing design equations for the Perfobond shear connector were briefly analyzed and the equation for the prediction of the shear capacity of T-shaped perforated shear connector was suggested empirically. By comparing the results obtained by the suggested equation, the existing equations for the Perfobond shear connector, and the experiment, the applicability and effectiveness of the suggested equation was estimated.


2019 ◽  
Vol 31 (6) ◽  
pp. 413-421 ◽  
Author(s):  
Min-Ki Lee ◽  
Kyung-Jae Shin ◽  
Jun-Seop Lee ◽  
Il-Soo Chae

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