• Journal of the Computational Structural Engineering Institute of Korea
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• v.31 no.1
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• pp.39-46
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• 2018

In this paper, an unbonded post-tensioning anchorage for a single-stranded wire that allows more efficient stress distribution in the post-tensioned anchorage zone was developed by using a finite element analysis using a commercial program. The stress analysis was carried out using a 3D model in the anchorage zone of the concrete member using the developed anchorage. The result of analysis ensured that the developed anchorage reduced the maximum bursting stress in anchorage zone compared to the case of existing anchorage and the location where maximum bursting stress also occurred closer to the anchorage. Bursting force was calculated using AASHTO, modified $M{\ddot{o}}rsch$ and Stone. As a result, it was concluded that an effective reinforcement design of the anchorage zone can be designed by modified $M{\ddot{o}}rsch$.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.1
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• pp.3-12
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• 2015

Bursting stress in anchorage zone of post tension girder can be estimated based on Guyon's equation. The major parameters in calculating bursting stress are prestressing force and the distance ratio between concrete edge and anchorage plate. Although Guyon's equation can be applied to calculate bursting stress for rectangular typed as well as circular typed plate, there is some limitation of accuracy due to 2 dimensional analysis. Therefore this study is proposed to suggest a bursting stress equation based on 3 dimensional finite element method.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.6
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• pp.63-71
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• 2018

Strands with ultimate strength of 2,400 MPa was developed and applied in the KCI Code and the KS standard. A high-strength prestressed strand to be applied to a structure, a suitable anchorage system should be used together. Recently, a post tension anchorage for 2,400 MPa strands was developed. but there is not much research on performance evaluation. Therefore, in this study, structural analysis of local zone with 9 strands, 15 strands, and 19 strands anchorage were investigated respectively, which are most widely used for post tensioning anchorages with 2,400 MPa strands, according to PTI anchorage zone design method, and Load transfer performance from ETAG013 and/or KCI-PS101 was evaluated. Furthermore, the adequacy of the test was also analyzed by nonlinear numerical analysis. As results, the anchorages with 2,400 MPa strands satisfied the structural performance of the local area and satisfied the load transfer performance condition.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.12
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• pp.21-26
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• 2018

For evaluating equations of bursting force in different codes, comparative study of the formulas was conducted. Because the equations does not consider variables such as shape of anchorages and duct, a relation between the bursting forces and the variables has to be analyzed. In this paper, the bursting forces equation was proposed by finite element analysis. As evaluation through comparison of the proposed equation with the previous ones and an experiment, it was figured out that bursting force computed by the proposed equation could be used for design of reinforcement in the anchorage zone.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.6
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• pp.73-83
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• 2016

Bearing stress near anchor plates is usually very high due to prestressing force in anchorage zone of concrete structure used post-tensioned prestressed method. In order to effective utilization of cross section and crack control, appropriate size of anchorage plates should be used to prevent crack initiation and failure of concrete structures eventually. This study aims to suggest equation for effective area of bearing plate of rectangle type and circular type by Highway Bridge Design Specification and PTI etc. A shape factor according to bearing plate shape is suggested based on numerical analysis, and it can be used suitability for design of special anchorage plate dimension.

• Journal of Korean Association for Spatial Structures
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• v.17 no.4
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• pp.69-76
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• 2017

For evaluating equations of bursting force in different codes, comparative study of the formulas was conducted. Because the equations does not consider variables such as shape of anchorages, angle of tendons, and eccentricity, a relation between the bursting forces and the variables has to be analyzed. In this paper, therefore, a comparative analysis of bursting forces computed by equations in the codes and finite element analysis was performed. As a result, it could be figured out that bursting force equations in the local zone were determined by coefficient k.

• Journal of Korean Association for Spatial Structures
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• v.18 no.3
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• pp.117-124
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• 2018

In the post-tensioned concrete member, additional reinforcement is required to prevent failure in the anchorage zone. In this study, the details of reinforcement suitable for the anchorage zone of the post-tensioned concrete member using circular anchorage was proposed based on the experimental results. The tests were conducted with the compressive strength of concrete and reinforcement types as variables. The experimental results indicated that the additional reinforcement for the anchorage zone is required when the compressive strength of concrete is less than 17.5 MPa. U-shaped reinforcement shows most effective performance in terms of maximum strength and cracks patterns.

• Journal of Korean Association for Spatial Structures
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• v.20 no.1
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• pp.41-48
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• 2020

In this study, the design of anchorage zone for unbonded post-tensioned concrete beam with single tendons of ultimate strength 2400MPa was evaluated to verify that the KDS 14 20 60(2016) and KHBDC 2010 codes are applicable. The experimental results showed that the bursting force equation of current design codes underestimated bursting stress measured by test, because the KDS 14 20 60(2016) and KHBDC 2010 propose the location of the maximum bursting force 0.5h which is the half of the height of member regardless of stress contribution. Although the allowable bearing force calculated by current design codes was not satisfied the prestressing force, the cracks and failure in anchorage zone was not observed due to the strengthening effect of anchorage zone reinforcement.