• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.101-104
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• 2005

This study is to develop detailing guidelines based on ductility demand for reinforced concrete bridge columns in areas of low to moderate seismicity. The current seismic design criteria of the Korea Design Specifications for Highway Bridge (KDSHB 2005) adopted the seismic design concept and requirements of the AASHTO specifications. In order to obtain full ductile behavior under seismic loads, i.e. when applied seismic force is larger than design flexural strength of column section, a response modification factor (R=3 or 5) is used. In moderate seismicity regions, however, adopting the full ductility design concept sometimes results in construction problems due to reinforcement congestion. The objective of this paper is to suggest a new simplified seismic design of reinforced concrete bridge columns for moderate seismicity regions.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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• pp.871-876
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• 2001

Recent earthquakes in California and Japan caused extensive damage to highway bridge structures. It is also thought that during probable earthquakes bridge structures in Korea could be failed due to the structural deficiencies, which were nonseismically designed and constructed before 1992. In these regards, innovative strengthening methods have been developed to repair reinforced concrete bridge columns, especially by glassfiber sheet bonding methods which are widely used today. The primary objective of this research is to investigate the seismic behavior of RC bridge columns retrofitted with composite straps and to propose pertinent guidelines of repair and rehabilitation method for earthquake resistant design procedure of RC bridges which are located in low or moderate seismicity regions. Six scaled-down concrete test specimens were made with test variables such as lap splice ratio, axial force ratio, confinement ratio, composite straps in the plastic hinge region. Pertinent design guidelines could be developed for the earthquake resistant design of RC bridge piers retrofitted with glassfibers in low or moderate seismic region.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.33-36
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• 2004

The current Korea bridge design specifications have no provisions about concrete Barrier. And there are no test results of registence strength of the concrete barrier at the vehicle collision sites. This paper reports experimental results of concrete barrier on bridge deck conctructed by standard drawing of SB5 grade. Eight specimens were tested under static test. The specimens are divided by two groups (D-series and B-series). D-series is to show failure pattern of bridge deck. B-series is to show failure pattern of concrete Barrier. The test results compared with calculation results using Yield-Line theory of AASHTO LRFD Bridge Design Specifications.

• Computers and Concrete
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• 제24권4호
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• pp.303-311
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• 2019

The depth of superstructure is the summation of the height of girders and the thickness of the deck floor. In this study, it is aim to determine the maximum span length of girders and minimum depth of the superstructure of prestressed concrete I-girder bridge. For this purpose the superstructure of the bridge with the width of 10m and the thickness of the deck floor of 0.175m, which the girders length was changed by two meter increments between 15m and 35m, was taken into account. Twelve different girders with heights of 60, 75, 90, 100, 110, 120, 130, 140, 150, 160, 170 and 180 cm, which are frequently used in Turkey, were chosen as girder type. The analyses of the superstructure of prestressed concrete I girder bridge was conducted with I-CAD software. In the analyses AASHTO LRFD (2012) conditions were taken into account a great extent. The dead loads of the structural and non-structural elements forming the bridge superstructure, prestressing force, standard truck load, equivalent lane load and pedestrian load were taken into consideration. HL93, design truck of AASHTO and also H30S24 design truck of Turkish Code were selected as vehicular live load. The allowable concrete stress limit, the number of prestressed strands, the number of debonded strands and the deflection parameters obtained from analyses were compared with the limit values found in AASHTO LRFD (2012) to determine the suitability of the girders. At the end of the study maximum span length of girders and equation using for calculation for minimum depth of the superstructure of prestressed concrete I-girder bridge were proposed.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표대회 논문집(III)
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• pp.706-711
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• 1998

Structural tests of the PSC Beam bridge using high strength concrete, concrete compressive strength 700kg/$\textrm{cm}^2$, are conducted for the application including durability and serviceability of the bridge. Current design safety factors with respect to the jacking force and the service design load DB-24 are applied to the design of the bridge. Concrete compressive strength 700kg/$\textrm{cm}^2$, girder depth 2.3m, girder space 3.2m, span length 20m, and slab thickness 27cm are selected for the bridge test. The Bulb-Tee section of the girders is applied instead of I section because it is well known more stable to the longer span(40m). Static load test(4 beams) with composite and non-composite section, and fatigue load test(1 beams) with composite section are conducted. Crack moment, ultimate load, deflections with load steps, and strains of the beam section for those bridges are investigated. The structural test results of the bridges showed a good performance for a safety and a serviceability.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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• pp.507-512
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• 2002

Prestressed concrete I-girders were used in the bridge applications in the early 1950s. During the last four decades, the most widely used girder length of bridges have been below 30 meters. The main objective of this study is to develope the alternative section for widely spaced girder of 30 meters span bridge. Girder spacing, the number of strands and compressive strength of concrete are major parameters for widely spaced girders. The optimal girder spacing is determined through the parameter studies of design using widely spaced girders. 30m span bridges of widely girder spacing must use high-strength concrete. Although the basic unit cost of concrete is higher for high-strength concrete, it may be partially or even fully offset by reduced quantities of concrete as result of the smaller number of girders used. High-strength concrete girders have more prestressing strands per girder, but the total number of strands for all of the girders is less than that required for the larger number of normal-strength concrete girders. It could design PSC-I Birdge with widely spaced girder owing to high-strength concrete.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회 논문집(II)
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• pp.1063-1068
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• 2000

Latex modified concrete (LMC) has grown to be accepted as a standard material of construction overlaying bridge decks in America due to its superior physical and chemical properties. The properties of latex, combined with the low water-cement ratio, produce a concrete that has improved flexural, tensile, and bond strength, lower modulus of elasticity, increased freeze-thaw resistance, and reduced permeability compared to conventional concrete of similar mix design. LMC overlays have been service in excellence for 30 years on thousands of bridge in U.S.A. This may, also, prolong the life cycle of bridge deck once it is adopted in Korea. The self-contained, mobile, continuous mixer is most appropriate particularly for concrete quality assurance. Assuring quality on a bridge deck overlay project should begin in the design phase and continue after the construction is completed. Quality should be the concern of everyone involved-owner, designer, and contractor.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1990년도 가을 학술발표회 논문집
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• pp.95-100
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• 1990

The behavior of short span filled spandrel arch bridge of 10 and 21 m span with various axis line, rise and backill height were investigated under the design loads(self weight, earth pressure, temperature load, live load, etc). Even though the behaviors of arch were known as relatively complicated, the followings can be concluded within the limits of this study. The design value of arch bridge increase as the rise decreases, the effects of temperature load become dominant for the design of arch bridge, and governing design factors are occured at springing.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
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• pp.251-256
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• 1999

In the preliminary design stage of Prestressed Concrete (PSC) Box Girder Bridges, the design factors(including depth, thickness of web, and jacking force) decided by inexperience designer could heavily affect the final design factors. So there is a possibility that the design ends up with an excessively wasteful design. To aim at an economical design with preventing an excessive design, the optimal design program has been developed by using ADS optimal program and SPCFRAME(PSC Bridge analysis program) in these studies. The optimal design program automatically calculates economically optimized design studies. The optimal design program automatically calculates economically optimized design factors by introducing the optimal design techniques of PSC box girder bridge design. The objective function for optimal design is material cost of box girder and constrained functions are constituted with design specifications and workability. The optimal design techniques used the Sequential Unconstraint Minimization Technique (SUMT) with performing the optimal design program. In this study, We designed unprismatic section bridge and prismatic section bridge in the same design condition by optimal design program developed in this study. By analyzing the results we suggested the practical form of tendon's layout comparing the optimal desingns on the basis of each tendon's layout.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.239-241
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• 2005

Reliability analysis of the design of reinforced concrete rahmen bridge is performed. Statistical properties for loads and resistances are taken into account in the analysis and the reliability indices are calculated for strength limit state of the current bridge design specification. Results are presented and discussed for different span lengths and wall heights.