• International Journal of Highway Engineering
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• v.9 no.2 s.32
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• pp.129-140
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• 2007

A major purpose of this study is to develop a drainage system that can quickly drain water penetrated into pavement layers to mitigate pot holes which is one of the major distress types in bridge deck pavements. This system can be established by applying a thin drainage layer between waterproof and pavement layers. The most important elements for this system are the performance of waterproof layer and construction technique for the thin drainage layer. The porous asphalt mix with the maximum aggregate size of 10mm is first developed based on the porous asphalt mix design guide proposed by NCAT, and various physical and mechanical tests are performed to confirm that the porous mix satisfies all the specification requirements. In addition, a series of laboratory tests including low-temperature bending and bonding strength tests for the MMA(Methyl Methacrylate) type of waterproofing material. It is observed from the tests that the MMA material satisfies all the specification requirements. To evaluate the Reld performance of the drainage system, a field study has been conducted on a relatively small size bridge. The QC/QA tests are conducted on the both waterproofing and pavement materials. It has been found that the drainage system works well to drain the water penetrated into the pavement layers.

• Journal of Korean Society of Steel Construction
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• v.26 no.5
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• pp.385-396
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• 2014

Traditionally, domestic steel design and construction practice has provided extra shear studs to moment frame beams even when they are designed as non-composite beams. In the 1994 Northridge earthquake, connection damage initiated from the beam bottom flange side was prevalent. The upward moving of the neutral axis due to the composite action between steel beam and floor deck was speculated to be one of the critical causes. In this study, full-scale seismic testing was conducted to investigate the side effects of the composite action in steel seismic moment frames. The specimen PN700-C, designed following the domestic connection and floor deck details, exhibited significant upward shift of the neutral axis under sagging (or positive) moment, thus producing high strain demand on the bottom flange, and showed a poor seismic performance because of brittle fracture of the beam bottom flange at 3% story drift. The specimen DB700-C, designed by using RBS connection and with the details of minimized floor composite action, exhibited superior seismic performance, without experiencing any fracture or concrete crushing, almost identical to the bare steel counterpart (specimen DB700-NC). The results of this study clearly indicate that the beams and connections in seismic steel moment frames should be constructed to minimize the composite action of a floor deck if possible.

• Journal of the Korea Concrete Institute
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• v.19 no.4
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• pp.393-399
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• 2007

Concrete bridge decks are directly exposed to the severe environmental conditions such as rain water and deicing chemicals resulting in the freeze-thaw action and the rebar corrosion during their service lift. These deteriorations of bridge decks shorten the service lift and consequently they are the major concerns of the maintenance. The high performance concrete (HPC) deck is proposed as the alternative to minimize the deterioration problems. To develop more durable concrete deck, the performance characteristic tests of HPC mixtures were carried out. In this study, 4 different concrete mixtures were used varying the mineral admixtures as the cement replacement; ordinary portland cement (OPC), 20% fly ash (FA),20% fly ash with 4% silica fume (FS), and 40% ground granulated blast-furnace slag (BS). The design compressive strengths of HPC specimens were 27 MPa and 35 MPa, respectively. The results showed that the compressive strength of concrete did not much affect the durability of concrete. HPC with fly ash and silica lune (FS) were turned out to have the good durability and crack resistance.

• Journal of Korean Society of Steel Construction
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• v.15 no.3
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• pp.321-329
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• 2003

To effectively use the cross section of concrete decks, analytical and experimental studies on prestressed steel-box-girder bridges were performed in this study. The method of applying prestress was determined in the analytical study and the longitudinal behavior of the prestressed steel-box-girder bridge was considered in the experimental study. The object model for these studies was a two-span continuous bridge. The method of applying prestress determined herein was divided into two parts: one is that apply prestress to the concrete deck at its intermediate support, and the other is that apply prestress to the lower flange of the steel-box-girder bridge at its end support. The prototype bridge for the experiment was simulated based on the rule of similitude and was fabricated according to construction steps to apply prestress effectively. From the results of the experimental study, it has demonstrated that the prestressed steel-box-girder bridge provides better performance than the general steel-box-girder bridge in view of the increase of the design live load, the reduction of the tensile stress of the concrete deck at intermediate support, and the reduction of the displacement.

• International Journal of Highway Engineering
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• v.11 no.3
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• pp.1-11
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• 2009

This study focuses on evaluating the applicability of an acryl based polymer concrete to the thin bridge deck pavements. The acryl concrete developed in this study is composed of Methyl Methacrylate(MMA) resin, benzol peroxide and fillers. To study the effects of the types and amounts of the components on the physical characteristics of the acryl concrete, viscosity, compressive strength and bending tests were conducted. The optimum mixture design was then determined based on the testing results. Several different types of laboratory tests, such as water and chlorine ion penetration tests, shrinkage and thermal coefficients tests, and tensile bonding strength tests were performed for the optimum acryl concrete and conventional cement concrete. The testing results show that water and chroline ion resistance, bonding strength between acryl and cement concrete and crack resistance of the acryl concrete is better than those of the conventional cement concrete. There are shortcomings that the conventional acryl concrete has a higher shrinkage and thermal coefficients. However, it was confirmed that to use newly developed rubberized MMA resin in this study reduces the crack resistance with substantially increased ductility.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.602-608
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• 2019

The purpose of this study was to calculate the temperature difference of the sectional elevation according to the asphalt thickness of the steel box girder bridge deck and provide data on the design basis accordingly. Asphalt thicknesses produced four steel box girder model specimens of 0mm, 50mm, 100m and 150mm. In each model, 17 to 23 temperature sensors were attached to upper concrete and steel box girders. Six temperature gauges were selected to compare the temperature difference with Euro codes. The maximum and lowest temperature were calculated at the reference atmospheric temperature of each model, and the temperature difference (slope) was calculated based on this calculation. Four models of temperature difference are presented at each model. The 0mm to 100mm temperature difference models showed a -0.9 to -1.5 degree lower temperature difference compared to the temperature difference of Euro codes at the top of the slab. Overall, the measured temperature difference was found to be between 5.45% and 8.33% compared to the Euro code. The standard error coefficient, which was calculated by multiplying the average temperature with the standard error, was calculated from a range of 2.50 to 2.51 times the average at the top and bottom. It is estimated that the proposed temperature difference model can be used as a basic data when calculating temperature difference criteria for bridges in Korea.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.35 no.2
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• pp.131-140
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• 2022

Installing Continuous Welded Rail (CWR) is one of the economical ways to resolve the challenges of noise, vibration, and the open-deck steel railway bridge impact, and the SSF method using the interlocking sleeper fastener has recently been developed. In this study, the method employed for determining the optimum vertical stiffness of the sleeper pad installed under the bridge sleeper, which is utilized to adjust the rail height and absorb shock when the train passes when the interlocking sleeper fastener is applied, is presented. To determine the optimal vertical stiffness of the sleeper pad, related existing design codes are reviewed, and, running safety, ride comfort, track safety, and bridge vibration according to the change in the vertical stiffness of the sleeper pad are estimated via flexible multi-body dynamic analysis,. The flexible multi-body dynamic analysis is performed using commercial programs ABAQUS and VI-Rail. The numerical analysis is conducted using the bridge model for a 30m-long plate girder bridge, and the response is calculated when passing ITX Saemaeul and KTX vehicles and freight wagon when the vertical stiffness of the sleeper pad is altered from 7.5 kN/mm to 240 kN/mm. The optimum stiffness of the sleeper pad is calculated as 200 kN/mm under the conditions of the track components applied to the numerical analysis.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.6
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• pp.689-693
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• 2023

Domestic bridges with a service life of more than 30 years are expected to account for approximately 54% of all bridges within the next 10 years. As bridges rapidly deteriorate, it is necessary to establish an appropriate maintenance plan. Recent domestic and international research have focused on the integration of BIM to digitize bridge maintenance information and then enhance accessibility and usability of the information. Accordingly, this study developed a BIM-FEM interoperability algorithm for bridge decks to convert maintenance information into data and efficiently manage the history of maintenance. After creating an initial crack BIM based on an exterior damage map, bridge specification and damage information were linked to a numerical analysis that performs damage analysis considering damage scenarios and design loads. The spread of cracks obtained from the analysis results were updated into the BIM. Based on the damage spread information on the BIM, an automated technology was also developed to assess both the current and future condition ratings of the bridge deck. This approach can enable an efficient maintenance of the deck using the history data from bridge inspection and diagnosis as well as future information on cracks and defects. The expected early detection and prevention would ultimately improve the lifespan and safety of bridges.

• Journal of Korean Society of Steel Construction
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• v.15 no.4 s.65
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• pp.341-358
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• 2003

This paper proposed a general formulation of Life-Cycle Cost (LCC) models and LCC effective design system models of steel bridges suitable for practical implementation. An LCC model for the optimum design of steel bridges included initial cost and direct/indirect rehabilitation costs of a steel bridge as well as repair/replacement costs, loss of contents or fatality and injury losses, road user costs, and indirect socioeconomic losses. The new road user cost model and regional socioeconomic losses model were especially considered because of the traffic network. Illustrative design examples of an actual steel box girder and an orthotropic steel deck bridge were discussed to demonstrate the LCC effectiveness of the design of steel bridges. Based on the results of the numerical investigation, the LCC-effective optimum design of steel bridges based on the proposed LCC model was found to lead to a more rational, economical, and safer design compared with the initial cost-optimum design and the conventional code-based design.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.5
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• pp.85-95
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• 2021

Structure design sensitivity was evaluated using the orthogonal array experimental method for passive-type deck support frame (DSF) developed for float-over installation of the offshore plant. Moreover, approximation characteristics were also reviewed based on various meta-models. The minimum weight design of the DSF is significantly important for securing both maneuvering performance and buoyancy of a ship equipped with the DSF and guaranteeing structural design safety. The performance strength of the passive type DSF was evaluated through structure analysis based on the finite element method. The thickness of main structure members was applied to design factors, and output responses were considered structure weight and strength performances. Quantitative effects on the output responses for each design factor were evaluated using the orthogonal array experimental method and analysis of variance. The optimum design case was also identified from the orthogonal array experiment results. Various meta-models, such as Chebyshev orthogonal polynomial, Kriging, response surface method, and radial basis function-based neural network, were generated from the orthogonal array experiment results. The results of the orthogonal array experiment were validated using the meta-modeling results. It was found that the radial basis function-based neural network among the meta-models could approximate the design space of the passive type DSF with the highest accuracy.