• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.647-652
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• 2000

The bond strength of latex-modified concrete to normal portland cement concrete measured with direct pull-out test. Using $250\times1100\times1400$mm concrete slab as the base concrete, an overlay of the latex-modified concrete is applied and cured similar to bridge deck and then tested in direct pull-out. The test results not only give values of the bond strength of the overlay tested but also clearly indicate whether the failure is in the bond interface or the materials tested.

• Journal of the Korean Society of Industry Convergence
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• v.7 no.2
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• pp.181-186
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• 2004

This study presents a optimization of structure, in which constraints contain the conditions of stress and serviceability, while the sequential linear programming method (SLP) is used as a rational approach. The optimum design results contained on the limit state constraints are compared with those obtained by the only stress and ministry of construction enacted standard plans. A simple slab bridge is analysed numerically for illustration of the structural optimization. It may be asserted that serviceability constraints is very important to a structure design.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.862-867
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• 2004

In this paper, the crack properties of steel fiber reinforced concrete (SFHC) beams by experimental method are discussed. The major role played by the steel fiber occurs in the post-cracking zone, in which the fibers bridge across the cracked matrix. Because of its improved ability to break crack, SFRC has better crack properties than that of reinforced concrete (RC). Crack properties are influenced by longitudinal reinforcement ratio, volume and type of steel fiber, strength of concrete and the stress level. Crack width and crack number in the SFRC beams havebeen evaluated from experimental test data at various levels in the beams.

• Earthquakes and Structures
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• v.12 no.3
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• pp.375-388
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• 2017

Prior to modern seismic provisions, several bridges were not designed for seismic actions in moderate seismic areas. Precast multi-girder and slab bridges are typical highway overpass structures; they have a significant contribution to national bridge stocks. Since the seismic behavior is questionable, a preliminary parametric study is conducted to determine critical configurations and components. The results indicate that the behavior of the abutments, backfill soil, superstructure and foundation is normally satisfactory; however, the superstructure-abutment joints are critical for both single- and multi-span bridges, while the piers are also critical for longer multi-span configurations. The parametric results provide a solid basis both for detailed seismic assessment and development of design concepts of newly built structures in moderate seismic zones.

• Journal of the Korea Concrete Institute
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• v.11 no.5
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• pp.21-31
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• 1999

The companion paper presents an analytical model to predict behaviors of PSC-Beam bridges according to continuity of spans. This paper aims at providing several examples of its application to PSC-Beam bridge. In this regard, many uncertainties affecting to the continuity of spans (such as the ultimate shrinkage strain of slab and girders, the prestressing creep of girders, and the time adopting prestressing force) are analysis in detail. Moreover, to increase the serviceability and to remove th inherent structural defects including the cracking at interior supports, a necessity for the parametric studies of PSC-Beam bridges reflecting the construction sequence is emphasized.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.1417-1424
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• 2010

To provide more safe road and better travelling service for Expressway customer, we minimize settlement of bridge backfill and properly repair the occurred settlement. So, we devide this study to two parts one is construction part and the other is management part, in construction part we remove settlement occuring elements and in management part we grasp proper repair time, and then we produce general settlement management program. In construction part, for the purpose of developing construction method of reducing settlement, we developed construction method models and they are composed of abutment back section alteration and backfill material alteration by literature reviews and site investigation of backfill settlement. And then, we carried out laboratory model test and full size field test of some developed models.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.266-269
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• 2006

External pre-stressing strengthening method is the most popular way to strengthen concrete structures because of its efficiency and economic advantage. The laboratory test was performed to reinforce the slave bridge with the external tendon strengthening by longitudinally and transversally, which is concerned with formal feature of slave bridge, generally. Based on this test, anchoring device to strengthen the external tendon strengthening method was established and its strengthening effects were verified by evaluating the load bearing capacity.

• 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.

• Journal of the Korea institute for structural maintenance and inspection
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• v.8 no.4
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• pp.185-193
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• 2004

Reasonable prediction of bridge deterioration is the most important factor in the determination of repair time or optimized maintenance policy for bridges. To accomplish these purposes, the proposed method is composed of quantitative condition assessment, Markov chains and Bayesian estimates. Example predictions of concrete slab bridges in Korea were illustrated with higher reasonability than those of existing methods such as expert opinion and visual inspection only.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.04a
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• pp.13-17
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• 2004

In recent years, the deterioration of reinforced concrete structures has become a serious problem in civil engineering fields. This situation is mainly due to corrosion of steel reinforcing bars embedded in concrete. Recently, there has been a greatly increased demand for the use of FRP (fiber reinforced plastic) in civil engineering field due to their superior mechanical and physical properties. This paper presents an experimental study on the behavior of concrete bridge deck reinforced with FRP Box, FRP Plate, and FRP Re-bar. In tlIe study, mechanical properties of FRP Box, FRP Plate, GFRP Re-bar, and CFRP Grid have been investigated. Full scale one-way deck slab was tested under four point lateral load (equivalent to actual wheel load of DB-24 including impact). Load-deflection and load-strain data were collected through LVDT's and strain gages attached to the specimen.