• International Journal of Highway Engineering
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• v.10 no.2
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• pp.193-203
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• 2008

This study was conducted to investigate the feasibility of the expedite construction of new pavement systems using precast concrete slabs and to develop the design and construction guide based on the results of the experimental construction. Half scale concrete slabs were designed and fabricated and the optimal reinforcement design, linkages between the slabs in the longitudinal and transverse directions, and the grouting methods were investigated. The experimental construction was performed fast and easily by assembling two slabs in the longitudinal direction and the other two in the transverse direction. The slabs were leveled and the pockets and the space between the slab bottom and the underlying layer were grouted. From the experimental construction, details about the design and construction of the precast pavements were acquired. Finally, the design and construction guide for the newly constructed precast concrete pavement systems was developed.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.23 no.3
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• pp.191-200
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• 2017

Proper packaging design can meet both the environmental and economic aspects of packaging materials by reducing the use of packaging materials, waste generation, material costs, and logistics costs. Finite element analysis(FEM) is used as a useful tool in various fields such as structural analysis, heat transfer, fluid motion, and electromagnetic field, but its application in the field of packaging is still insufficient. Therefore, the application of FEM to the field of packaging can save the cost and time in the future research because it is possible to design the package by computer simulation, and it is possible to reduce the packaging waste and logistics cost through proper packaging design. Therefore, this study investigated the FEM papers published in Korea for the purpose of helping research design using FEM program in the field of packaging in the future. In this paper, we analyzed the 29 papers that were directly related to the analysis of FEM papers published in domestic journals from 1991 to 2017. As a result, we analyzed the research topic, FEM program, and analysis method using each paper, and presented the direction that can be applied in future packaging field. When the FEM is applied to the packaging field, it is possible to change the structure and reduce the thickness through the stress and vibration analysis applied to the packaging material, thereby reducing the cost by improving the mechanical strength and reducing the amount of the packaging material. Therefore, in the field of packaging research in the future, if the FEM is performed together, economical and reasonable packaging design will be possible.

• 한국도로학회:학술대회논문집
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• 2009.11a
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• pp.465-469
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• 2009

• International Journal of Highway Engineering
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• v.12 no.4
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• pp.165-174
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• 2010

This study was conducted to evaluate the feasibility of expedite repairing of concrete pavements using precast concrete pavement method and to investigate the effectiveness of slab connection methods. In the demonstration construction, four slabs of jointed concrete pavements were replaced with the precast slabs. First, precast concrete slabs were designed and fabricated, then existing slabs were cut and removed, and finally precast slabs were installed. The slabs were leveled and pockets, holes, and space between the slab bottom and the underlying layer were grouted. From the demonstration construction, details about the design and construction of the precast pavements for repairing of pavements were evaluated. In addition, the slab connection methods such as pocket and hole connection methods were applied in the construction and the slab curling behaviors at the joints that include those connection methods were compared. The results showed that both slab connection methods were applicable, and the hole connection method was superior.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6D
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• pp.951-960
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• 2006

Structural pavement analysis considering lateral loads of moving vehicle was carried out in order to simulate passing vehicle loads under various interface conditions. To verify of existing multi-layer elastic analysis of layer interface effect parameters, this study compared outputs by using ABAQUS, a three dimensional finite element program and KENLAYER, multi-layer elastic analysis as vertical load was applied to the surface of asphalt pavements. Pavement performance depending on interface conditions was quantitatively evaluated and fundamental study of layer interface effect parameters was performed in this study. As results of the study, if only vertical loads of moving vehicle is applied, subdivision of either fully bonded or fully unbonded is enough to indicate interface effect parameters. On the other hand, when lateral loads are applied with vertical loads, pavement behavior and performance are greatly changed with respect to layer interface conditions. The thinner thickness of the asphalt layer is and the smaller elastic moduli of the asphalt layer is, the more pavement behavior is influenced by interface conditions. In addition, regression analysis equation analytically computing tensile strain which was considered thicknesses and elastic moduli of the asphalt layer and layer interface effect parameters at the bottom of the asphalt layer was presented using database from numerical analyses on national pavement model sections.

• International Journal of Highway Engineering
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• v.14 no.3
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• pp.25-32
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• 2012

The thickness of anti-freezing layer has been empirically determined using the frost depth obtained from the freezing index and has not been generally considered as a structural layer in pavement design procedure. In fact, the anti-freezing layer makes a role in structural layer and enables to reduce the total thickness of pavement system. The objective of this study is to develop the statistical regression model for evaluating the structural capacity of anti-freezing layer using Falling Weight Deflectormeter(FWD) test data in asphalt pavements. The FWD testing was conducted at the embankment, cutting, and boundary area of various test sections to estimate the structural capacity of anti-freezing layer in different foundation condition. It is observed from this testing that the center deflections of pavement structure with anti-freezing layer are smaller than those without anti-freezing layer ranging from 0.4 to 82.6%. To determine the variables of statistical model, the correlation study has been conducted between various FWD deflection indexes and the anti-freezing layer thickness. It is found that the ${\Delta}BDI$(%)(${\Delta}Basin$ Damage Index(%)) is highly correlated with anti-freezing layer thickness. The ${\Delta}BDI$(%) model were developed for evaluating structural capacity of anti-freezing layer using linear mixed-effect models.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.15 no.3
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• pp.83-91
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• 2009

It is very difficult to export the fresh agricultural products to long distance countries such as USA and EU without any damage. Fresh products exporting would overcome very severe conditions such as hot and cold weather changes, heavy vibrations with rolling and pitching during the target distribution period, therefore, the packaging needs the immobility of products in the container and the keeping its quality by packaging materials or methods under any surrounding environments, especially. The physical strength of outer box should be designated according to its own characteristics for agricultural product packaging. Packaging dimension which would be fit to standard pallet is also very important factor to reduce the distribution cost. There have been many agricultural products researches for export packaging to the USA so far. However they have never got desirable results which enough to apply it in real. The main purpose of this research is to develop optimum compressive strength and optimum dimension of corrugated fiberboard box which would be used to USA export packaging of fresh melon as well as Japan.

• 한국도로학회:학술대회논문집
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• 2002.10a
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• pp.287-294
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• 2002

• Ecology and Resilient Infrastructure
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• v.3 no.4
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• pp.272-278
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• 2016

Porous pavements are recommended as a Low-Impact Development (LID) method which is a strategy to develop a water cycle as close to a natural state as possible, and to solve the urban impervious surface problems. Porous pavements can yield a solution if it provides a more permeable surface with extra space to contain extra water from building roofs. But there are few applications in Korea because of a lack of recognition and experience. Highway engineers are mainly concerned about the infiltration of water into pavement structures. They worry about the weakening of the asphalt mixture and subgrade, and freezing during the winter season due to the infiltration of water. Meanwhile, hydrological experts doubt the effects of the amount of water to control during the flooding season, and environmental experts prefer a non-point pollution treatment system established beside highway. In this study, from reviewing the history and the body of literature about porous pavements, conclusions regarding the most advanced technologies were made. First, traditional thickness designs can be used for porous pavement, no extra distresses was found by weakening and freezing during the winter season. Second, hydrological design can be made by controlling the thickness of the pavement and the outlet of water. Third, the treatment efficiency of non-point pollution of porous pavements is not worse than any other method. Importantly, it's a more eco-friendly solution because of its lower requirement for de-icing agents.

• International Journal of Highway Engineering
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• v.8 no.3 s.29
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• pp.49-61
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• 2006

This study suggests long-life asphalt pavement method which can save maintenance cost by increasing the design and performance period of pavements. The high modulus asphalt binder developed and then various physical tests are performed. Laboratory performance tests and accelerated pavement test are conducted for the high modulus and conventional mixtures. The test results show that dynamic modulus values of high modulus mixtures are higher than those of the conventional mixtures, The high modulus mixtures yield better fatigue, rutting and moisture damage performance than conventional mixtures. Structural analysis is performed and a database is built up for long life asphalt pavement design. Pavement response model is developed through a multiple regression analysis program, SPSS using the database. A design software for the long life pavements is developed based on the pavement response model and laboratory and field performance tests results. In addition, optimum pavement sections and materials are suggested. The suggested AC thickness of long life asphalt pavement is 29cm. A Life cycle cost analysis(LCCA) is conducted to check the economical efficiency of the long life pavement section. The LCCA result shows that initial construction costs of long life and conventional pavements are almost equal, but long life pavement is more profitable in terms of the LCCA.