Behavior of headed shear studs in stub–girder stub assemblages

1986 ◽  
Vol 13 (1) ◽  
pp. 106-115
Author(s):  
T. W. K. Chan ◽  
T. Rezansoff ◽  
M. U. Hosain

The paper summarizes the results of push-off tests conducted on 42 end stub assemblages. Written for conventional composite construction, the current Canadian Standards Association (CSA) standard on stud connectors offers little guidance for stub–girder design. A stud spacing of four times the stud diameter (the CSA requirement) does not appear to be adequate for a full development of the potential shear capacity of a stud connector in the stub–girder system. The required minimum stud spacing appears to be between five and six times the stud diameter for the case of 13 mm studs. Moreover, the CSA-recommended shear capacity of stud connector should be reduced to reflect the effect of prying forces. A modification factor of 0.9 is suggested for a 13 mm diameter stud connector. Test results for specimens with 19 mm studs indicated a further decrease in the shear capacity. However, a definite recommendation is postponed pending further tests.In addition to prying forces, stud configuration and spacing and the amount and location of transverse reinforcement must also be taken into account in determining the shear capacity of a stud connector. For a connection with 13 mm studs arranged in a single row, a reduction factor equal to stud spacing divided by six times the stud diameter is suggested when the stud spacing is less than six times the stud diameter. For a connection with staggered studs, the corresponding factor is obtained by dividing the stud spacing by five times the stud diameter when the stud spacing is less than five times the stud diameter. Key words: headed stud, shear capacity, minimum stud spacing, prying force.

2020 ◽  
Vol 8 (3) ◽  
pp. 127-136
Author(s):  
Taufiq Saidi ◽  
Rudiansyah Putra ◽  
Zahra Amalia ◽  
Munawir Munawir

Proper design of transverse reinforcement in the RC column is needed to maintain its ability to deform under axial and shear load safely. Even though mandatory building codes for transverse support of the RC column exist, shear failure was still found in the last high earthquake in Pidie, Aceh, in 2016. Therefore, as an attempt to improve RC column strength and elasticity, the effect of transverse reinforcement configuration was evaluated experimentally to a column subjected to an axial and shear load. The experiment was conducted by using four-column specimens with a cross-section 200 x 200 mm. Four types of transverse reinforcement configurations were applied in each column. The test was carried out by loading an axial load always and shear load gradually until its failure. The test results show that the configuration of transverse reinforcement has a significant effect of maintaining column stiffness, which was subjected to compressive axial load and shear load. Furthermore, the arrangement of transverse reinforcement influences the compressive strength significantly and enhance the concrete shear capacity of a column due to its confinement effect.


2013 ◽  
Vol 3 (1) ◽  
Author(s):  
Krishnamurthy Pandurangan ◽  
Gangolu Rao

AbstractFusion bonded epoxy coating is one of the methods used to protect steel against corrosion. The primary objective of this research reported in this paper is to evaluate the bond strength of epoxy coated bar splices confined with lateral reinforcement. Six full scale beams specimens, designed to fail in bond- splitting mode, were tested in positive bending. Each beam was reinforced with bars spliced in the constant moment region at mid span. The main variables were the amount of transverse reinforcement in the splice region and the coating to the bar. Test results indicate that transverse reinforcement improves the bond strength of coated bars and the ductility of the beams. The bond strength of coated bars is 93%, 72% and 59% of uncoated bars for confinement indices of 1.8, 1.4 and 1.26 respectively. Moreover, a bond reduction factor of 1.35 is suggested for use in code in place of 1.5,when the confinement index is greater than 1.4.


1994 ◽  
Vol 21 (4) ◽  
pp. 614-625 ◽  
Author(s):  
E. C. Oguejiofor ◽  
M. U. Hosain

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.


2019 ◽  
Vol 9 (21) ◽  
pp. 4513
Author(s):  
Min Sook Kim ◽  
Joowon Kang ◽  
Young Hak Lee

An improved shear strength equation is proposed that considers transverse reinforcement spacing and support conditions for concrete wide beams. Eighteen specimens were fabricated to examine the influence of transverse reinforcement spacing, the number of transverse shear reinforcement, and support width on shear capacity. From the test results, a shear strength equation is proposed and used to evaluate the shear strength of 23 specimens from previous studies and 18 from this study. For the 41 specimens, the proposed shear strength equation results had a mean of 1.16 and a standard deviation of 0.16. It showed that the proposed shear strength equation can predict shear strength reasonably well for concrete wide beams.


2002 ◽  
Vol 82 (1) ◽  
pp. 153-155
Author(s):  
S. L. Fox ◽  
L. K. Blomquist

A shield was developed to mount on a small plot combine header to separate and flatten adjacent unwanted rows from selected rows being harvested. Additional shielding was added underneath the combine to prevent stray spikes from discarded rows entering the combine. Approximately 25% more single row plots could be harvested per day with a plot combine modified with this device. Key words: Equipment, modification, wheat


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>


2020 ◽  
Vol 23 (3) ◽  
pp. 640-654
Author(s):  
Do Quang Thang

Introduction: This paper focuses on the derived equations to evaluate the ultimate strength of ring-stiffened cylinders with local denting damage under combined loadings. The damage generation scenarios in this research are representing the collision accidents of offshore stiffened cylinders with supply ships. Methods: Numerical analysis of structures are performed using Abaqus software after validation against the experiments from the authors. The responses from seventeen cylinder specimens are analyzed to develop the numerical methods. Results: Good accuracy results were achieved when comparing the test results and the simulation results. Parametric studies are then performed on design examples of ring-stiffened cylinders when considering both intact and damaged conditions for assessing the reduction factor. Then, the novel simple design equations to assess the residual strength of ring-stiffened cylinders after ship collision are derived based on the regression analysis. These equations have good accuracy with mean value Xm (Uncertainty modeling factor) around 1.0 and together with COV (Coefficient of Variation) lower than 5.3%. Conclusion: The accuracy and reliability of the derived equations are validated by comparing it with the existing test data in open access. It is concluded that the proposed equations have high accuracy and reliability, and convenient application for the purpose of checking the residual strength of dented offshore cylinder under ship collisions.


2019 ◽  
Vol 35 (3) ◽  
pp. 1163-1187 ◽  
Author(s):  
Ramazan Ozcelik ◽  
Elif Firuze Erdil

Three story–three bay reinforced concrete (RC) frames with and without chevron braces were tested using the continuous pseudodynamic test method. New steel–concrete composite lateral load–carrying members called Buckling Restrained Braces (BRBs) were used as chevron brace members while retrofitting the RC frame. The BRBs were fitted to the interior span of the RC frame by using anchorage rods. The chevron braced frame was observed to be effective in controlling interstory drift. The test results indicated that retrofitting with BRBs was beneficial in resisting deformation without significant damage under simulated ground motions. Furthermore, significant yielding that occurred on the core plate of the BRBs enabled the braced frame to dissipate energy induced by dynamic loading. The test results were compared with the results of the nonlinear time-history analysis. The analysis results were capable of estimating the base shear capacity and displacement demands with reasonable accuracy.


1996 ◽  
Vol 23 (5) ◽  
pp. 1051-1063 ◽  
Author(s):  
J. L. Humar ◽  
M. A. Rahgozar

The Geological Survey of Canada is currently producing a suite of new hazard maps for Canada. These maps take into account the additional recorded data obtained during the past 13 years, as well as the new geological and tectonic information that has recently become available. They provide elastic spectral acceleration values for a uniform probability of exceedance of 10% in 50 years. A method of using the uniform hazard spectral values to obtain design response spectral curves for different values of ductility is presented here. The method uses two spectral values obtained from the hazard maps, the peak spectral acceleration for the site and the spectral acceleration corresponding to a period of 0.5 s. Empirical expressions are developed to represent the design response spectra. It is shown that by using inelastic spectral accelerations rather than the elastic spectral values in association with a reduction factor, the new method provides a more reliable estimate of the design forces. Key words: uniform hazard spectra; inelastic spectra, seismic design forces, force modification factor, foundation factor, seismic hazard for Canada.


2011 ◽  
Vol 94-96 ◽  
pp. 1983-1988
Author(s):  
Jia Song ◽  
Zhen Bao Li ◽  
Yong Ping Xie ◽  
Xiu Li Du ◽  
Yue Gao

An experimental study was made of the mechanical properties of large scale confined concrete subjected to the axial compression test. Eleven tied concrete columns and six plain concrete prisms were tested. In the test, each specimen had the same transverse reinforcement configuration, and similar volumetric ratio of lateral steel, while different size. The test results in this paper indicate that the size of the specimen has no obvious relationship with the ultimate strength, however, it does affect the post-peak ductility to some extent. As a supplement to the experimental study, a finite element method was adopted to imitate the mechanical behavior of the confined concrete under axial compression. The results of the imitation in this paper indicate the confinement mechanism of large scale specimens.


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