• Structural Engineering and Mechanics
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• v.48 no.2
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• pp.221-239
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• 2013

This paper focuses on a development of strut-and-tie model (STM) to predict the capacity of an improved longitudinal joint for decked bulb-tee bridge systems. Nine reinforced concrete beam/slab specimens anchored by spliced headed bars with different details were tested. Test results were evaluated and compared with an anticipation of the validated STM. The proposed STM provides a lower bound of the ultimate capacity of the joint zone. It shows that the lap length of headed bars has a significant effect on structural behaviors of the improved joint. To develop a full strength joint, the range of the lap length can be determined by the strength and compatibility requirement. Design recommendations to spliced headed bars, concrete strength, as well as lacer bars in the joint zone are proposed for developing a full strength joint.

• The Journal of the Korea Contents Association
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• v.17 no.4
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• pp.108-118
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• 2017

This study focuses on an effectiveness of socially recommended advertising on social network sites (SNSs) and investigates the impact of three critical factors on SNS advertising effectiveness - reward type for advertising recommenders' intention, product type on advertisements, and tie strength. A $2{\times}2$ factorial design was used to test the interaction effects between the two variables, reward type and product type on advertisements, moderated by tie strength. The results indicate that when participants observe socially recommended advertising, hedonic product ads with non-monetary reward shows the most effectiveness, and reward type and product type are also effective. In the combination of reward type and product type, we have confirmed the regulating factor influencing the effectiveness of social advertising according to the tie strength between the recommenders and the consumers. Strong-tie recommenders have more influence on the effectiveness of the social advertising than weak-tie recommenders. Based on these results, theoretical and practical implications were provided to refine marketing environments on SNSs.

• Journal of the Korean Society of Clothing and Textiles
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• v.37 no.2
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• pp.186-201
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• 2013

This study investigates the effects of information type, direction of information, method of suggestion, tie strength, and interactions among these variables on the acceptance and diffusion of fashion product information in the mobile Facebook environment. Two subsequent studies were conducted to test the relationships among mobile SNS WOM factors. Two independent on-line surveys were implemented. Six hundred forty consumers aged between 20 and 39 were recruited for Study 1, and four hundred and eighty for Study 2. We manipulated the WOM delivery situation by information type (factual/evaluative), information directionality (positive/negative), tie-strength (strong/weak), and information presentation method (text/image/rink). Eight scenarios were developed and randomly assigned to the research participants. Frequency analysis, reliability, factor analysis, regression analysis, and ANOVA were implemented using SPSS 18.0. The Analysis of experiment data produced interesting results. Most WOM factors (including the information type, information presentation method, and tie strength) influence WOM acceptance; however, only the tie strength effected WOM activity. It was also proven that people are prone to accept information that is more realistic, objective, and negative, and they tend to accept information with visual factors, such as images and video clips rather than a simple text message. In this study, we offer a practical perspective to fashion industry and marketers who have an interest in SNS marketing. We have defined the distinct characteristics of mobile WOM that have been formed by a combination of former on/off-line WOM characteristics. To examine the moderating roles of two types of consumer innovativeness, fashion innovativeness and technology innovativeness were also measured and found to have significant moderating effects between mobile SNS WOM factors and their consequences. The paper concludes with a discussion on managerial implications and limitations.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.6
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• pp.2195-2209
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• 2013

The effective strength of concrete struts must be determined accurately for the reliable strut-tie model analysis and design of structural concrete. In this study, the equations of the effective strength, which are useful for the three types of determinate and indeterminate strut-tie models of reinforced concrete deep beams employed in current design codes, are proposed. The effects of shear span-to-effective depth ratio, compressive strength of concrete, and flexural and shear reinforcement ratios are reflected in the development of the proposed equations. To examine the appropriateness of the proposed equations, the strengths of 241 reinforced concrete deep beams, all tested to shear failure, are evaluated by using the three types of strut-tie models with the existing and proposed equations.

• Journal of the Korea Society of Computer and Information
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• v.26 no.7
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• pp.103-108
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• 2021

In this paper, we an empirical study of the effects of control types on Tie strength and filed project performance of project participants in field project organization for Korean domestic construction industry. In the study, we try to tell what significant impact output control, process control and tie strength among field project participants have on field project performance and features unique to field project organization for Korean construction industry through empirical analysis. And the findings of the empirical analysis are that output control appeared to have significant impacts on tie strength among the participants and process control, and process control also appear to have significant impact on field project performance.

• Structural Engineering and Mechanics
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• v.18 no.2
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• pp.151-166
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• 2004

The interaction between concrete core expansion and deformation of perimeter ties has been known to have a significant effect on the effective confinement of rectangular reinforced concrete (RC) tied columns. This interaction produces passive confining pressure to the concrete core. Most existing models for determining the response of RC tied columns do not directly account for the influence of flexural stiffness of the ties and the variation of confining stress along the column height. This study presents a procedure for determining the confined compressive strength of RC square columns confined by rectilinear ties with various tie configurations considering directly the influence of flexural flexibility of the ties and the variation of confining stress along the vertical direction. The concept of area compatibility is employed to ensure compatibility of the concrete core and steel hoop in a global sense. The proposed procedure yields satisfactory predictions of confined strengths compared with experimental results, and the influence of tie flexibility, tie configuration and degree of confinement can be well captured.

• Journal of Korean Society of Steel Construction
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• v.28 no.3
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• pp.129-138
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• 2016

Buckling of surface plates is an important limit state in Steel-Plate Concrete (SC) walls under axial compression. The surface plates may be anchored to concrete using connectors of studs or tie-bars. In this paper, the effects of studs and tie-bars on buckling of surface plates were evaluated by conducting tests. Experiments have three types of connectors; all studs, all tie-bars, and the combination of studs and tie-bars. Also, experiments have the various ratios of stud or tie-bar spacing to surface plate thickness. The experimental investigation shows that the buckling shape and strength of the surface plate of SC wall with the combination of studs and tie-bars have good agreements with that of the surface plate of SC walls with all studs or all tie-bars.

• Journal of the Korea Institute of Building Construction
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• v.15 no.5
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• pp.465-471
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• 2015

This study proposed V-shaped tie bar method as an alternative of internal cross-tie for reinforced concrete columns in order to enhance the constructability and confinement effectiveness of the lateral tie bars. A total of 35 pull-out specimens were prepared with the parameters of concrete compressive strength and bending angle and embedment length of the V-shaped bar to examine the bond stress-slip relationship of the V-shaped tie bar. The bond strength of the V-shaped tie bars with the bending angle not exceeding $60^{\circ}$ was higher than the predictions obtained from the equations of CEB-FIP provision. Considering the constructability and bond behavior of the V-shpaed tie bar, the bending angle and embedment length of such bar can be optimally recommended as $45^{\circ}$ and 6db, respectively, where db is the diameter of the tie bar.

• Computers and Concrete
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• v.17 no.2
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• pp.157-172
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• 2016

This paper presents a Strut-and-Tie Model for reinforced concrete (RC) columns subject to lateral loading. The proposed model is based on the loading path for the post-yield state, and the geometries of struts and tie are determined by the stress field of post-yield state. The analysis procedure of the Strut-and-Tie Model is that 1) the shear force and displacement at the initial yield state are calculated and 2) the relationship between the additional shear force and the deformation is determined by modifying the geometry of the longitudinal strut until the ultimate limit state. To validate the developed model, the ultimate strength and associated deformation obtained by experimental results are compared with the values predicted by the model. Good agreements between the proposed model and the experimental data are observed.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.544-547
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• 2004

Predicting the failure modes of reinforced concrete corbels is difficult because the reinforced concrete corbels show the shapes of sudden shear failures at even slight deflection. For this reason, an exact analysis method is demanded highly. In this study, the validity of the grid softened strut-tie model method suggested for concrete member analysis was examined through the ultimate strength evaluation of the reinforced concrete corbels tested to failure. The evaluated ultimate strengths by the grid softened strut-tie model method were compared with those by the ACI 318-02 and the softened strut-tie model method.