• Geomechanics and Engineering
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• v.24 no.6
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• pp.589-597
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• 2021

The present study evaluates geocell reinforced slope behavior. A three dimensional analysis is carried out to simulate soil and geocell elastoplastic behavior using the finite difference software FLAC3D. In order to investigate the geocell reinforcement effect, the geocell aperture size, thickness, geocell placement condition and soil compaction had been considered as variable parameters. Moreover, a comparison is evaluated between geocell reinforcing system and conventional planar reinforcement. The obtained results showed that the pocket size, thickness and soil compaction have considerable influence on the geocell reinforcement slope performance. Moreover, it was found that the critical sliding surface was bounded by the first geocell reinforcement and the slope stability increases, by increasing the vertical space between geocell layers. In addition, the comparison between geocell and geogrid reinforcement indicates the efficiency of using cellular honeycomb geosynthetic reinforcement.

• International Journal of Highway Engineering
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• v.13 no.2
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• pp.103-114
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• 2011

Usage of bicycle has been supported the universal reduction of energy consumption and $CO_2$. For the same purpose, new constructions for long length bike roads are planned in Korea. Recently, laboratory tests of physical properties and resistance against environmental loading about optimum mix design of roller compacted concrete, that have advantages of high structural performance by cement hydration and aggregate interlocking, simple construction procedure and low construction cost, are performed for the effective construction of new bike roads. However, properties of roller compacted concrete had different results between laboratory and field tests since it had different compaction method. Also, construction method of roller compacted concrete are not defined for the application of bike roads since it had different demand performance such as thin pavement thickness, low strength and etc with road pavements. Thus, in this experimental research was launched to evaluate the core properties, visual inspection, compaction ratio, water content, thickness reduction rate of roller compaction, skid resistance and roughness by experimental construction about variable mix proportion and compaction method based on laboratory test results. And construction method of roller compacted concrete pavement were suggested for the application of bike roads.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.7 no.6
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• pp.681-692
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• 2017

In recent years, large-scale construction projects such as road pavement construction and new city construction have been carried out nationwide with by the expansion of social overhead facilities and base on the economic development planning, resulting in a rapid increase in artificial slope damage. The existing vegetation-based re-installation method of the slope surface greening method reveals various problems such as lack of bonding force, drying, and lack of organic matter. In this study, research was carried out using vegetation-based material and environmentally friendly soil additives, were are used in combination with natural humus, Bark compost, coco peat, and vermiculite. Uniaxial compressive strength was measured according to the mixing ratio of soil additives and the strength was analyzed. Experiments were carried out on the characteristics of the soil material to gauge the slope protection properties by using the soil compaction test method wherein the soil and the soil additive materials are mixed in relation to the soil height, the number of compaction, the compaction method (layer) and the curing condition. As a result of the experiment, excellent strength performance was demonstrated in soil additives using gypsum cement, and it satisfied vegetation growth standards by using performance enhancer and pH regulator. It was confirmed that the strength increases with the mixing of soil and soil additive, and the stability of slope protection can be improved.

• Journal of the Korean Geotechnical Society
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• v.40 no.2
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• pp.81-93
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• 2024

In Korea, numerous large-scale infrastructure construction projects and housing site developments are being undertaken. However, due to limited land availability, sourcing high-quality backfill materials that meet the standards for railroad and road embankment compaction and mechanically stabilized earth (MSE) retaining wall construction poses significant challenges. Concurrently, there has been an increase in structural failures of many MSE retaining walls, attributed primarily to reduced bearing capacity and impaired drainage performance, resulting from inadequate backfill compaction. This study aimed to analyze the structural performance and safety of an MSE retaining wall using recycled soil as backfill. We conducted small-scale model tests utilizing 3D printing technology combined with two-dimensional numerical analysis. The study quantitatively evaluated the MSE retaining wall's performance concerning the recycled soil mixing ratio and reinforcement installation methods. Furthermore, the utility of 3D printing was confirmed through the production of an experimental wall designed to facilitate easy reinforcement attachment, mirroring the conditions of actual MSE retaining wall construction.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.738-739
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• 2006

This paper will describe a powder and processing method that facilitates single press-single sintered densities approaching $7.5g/cm^3$. At this sintered density, mechanical properties of the powder metal (P/M) component are significantly improved over current P/M technologies and begin to approach the performance of wrought steels. High performance gears have the added requirement of rolling contact fatigue durability that is dependent upon localized density and thermal processing. Combining high density processing of engineered P/M materials with selective surface densification enables powder metal components to achieve rolling contact fatigue durability and mechanical property performance that satisfy the performance requirements of many high strength automotive transmission gears. Data will be presented that document P/M part performance in comparison to conventional wrought steel grades.

• Journal of the Society of Disaster Information
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• v.9 no.1
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• pp.56-64
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• 2013

The study examines the quiet pavement using fine-size aggregates and warm-mix technique to reduce traffic noise. In order to evaluate the quality of pavement, mix design and laboratory tests were carried out. Test results showed that using 10mm aggregates can reduce the cantabro loss compared with 13mm aggregates due to increase contact area between aggregates. Mixing and compaction temperatures of warm mix quiet pavement should be determined by gyratory compactor test because it is used high viscosity asphalt binder. Using warm-mix additive could reduce compaction temperature by about $15^{\circ}C$. Noise measurement and permeability tests were conducted at the test road for evaluation of the field performance. All of quiet pavements meet the standard of permeability and have sufficient porosity. Noise reduction of the quiet pavement using fine-size aggregates is more effective than that using 13mm aggregates. In particular, the effect of noise reduction was noticeable at low speeds.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.117-124
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• 2000

As the reinforced earth wall is constructed with step by step backfill compaction method, the accumulative horizontal deformation is inevitable. It has been reported that about 80% of horizontal deformation is occurred during the construction stage of reinforced earth retaining wall. To reduce the horizontal deformation, an isolated-reinforced earth wall method(KOESWall system) was newly developed. In this system, the reinforced earth is constructed first with reinforcements and backfills only, and then facing blocks are installed after the horizontal displacement of reinforced earth is fully occurred. To evaluate the effect of a construction method and the performance of KOESWall system, two cases of full scale field performance was monitored during and after the construction stages.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.193-194
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• 2021

Ti-salt agglomerated titanium dioxide photocatalyst from sludge, which has various and excellent functions such as nitrogen oxide removal performance, antifouling performance, and bacteria removal performance, is intended to be applied to UHPC. The UHPC used in this study is supposed to have a high compressive strength of 100~200MPa and a high flowability of 600mm or more with a slump flow. Titanium dioxide is fixed to the UHPC surface by sieving through a test sieve and compaction and painting using a vibration compactor, and this is tested according to ISO 22197-1. The NO removal amount is evaluated by classification the result range.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.1
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• pp.7-12
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• 2017

Most of existing buried pipes are composed of reinforced concrete. Reinforced concrete pipes have many problems such as aging, corrosion, leaking, etc. The polyethylene (PE) pipes have advantages to solve these problems. The plastic pipes buried underground are classified into a flexible pipe. National standard that has limited the long-term vertical deformation of the pipe to 5% for flexible pipes including PE pipe. This study presents a prediction for the long-term behavior of the polyethylene pipe based on ASTM D 5365. This prediction method is presented to estimate by using the statistical method from the initial deflection measurement data. We predict the behavior of long-term performance on the double-wall pipe and multi-wall pipe. As a result, it was found that the PE pipe will be sound enough more than 50 years if the compaction of soil around the pipe is more than 95% of the standard soil compaction density.

• Journal of the Korean Electrochemical Society
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• v.6 no.1
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• pp.53-58
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• 2003

It is well known that the anode substrate of anode-supported type SOFC should have high electrical conductivity and high gas permeability to minimize the polarization loss of the cell performance during operation. In this study, we made anode substrates of SOFC with two different methods, which gave different anode microstructures, especially different pore structures with each other. We performed electrical and microstructural characterization of Ni/YSZ cermet anode via extensive measurements of its electrical conductivity and gas permeability combined with adequate image analysis based on quantitative stereological theory