• Journal of the Korean Home Economics Association
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• v.12 no.1
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• pp.459-471
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• 1974

This study was carried out on the thermal transmission on account of variation of weaves and researched on the selection of the most suitable weaves for warmth. Also the interrelation among the density, thickness and thermal transmission by different weaves was studied, the author has woven three fundamental weaves, five weaves derived from the fundamental weaves and two special weaves for the purpose of experiment. In weaving of fabrics for experiments the lever type hand loom was used. Testing of texture was carried out according to KS and ASTM. The thermal transmission was also tested by as cooling method which were developed by the author. The conclusions of experiments were as follows. 1. Matt weaves, honey comb weaves and satin weaves having long floating yarns have large cover factor and were thicker. these structures of the weaves were good in warmth. 2. Thermal transmission was reciprocated to the cover factor, thickness and value of cover factor multiplied by thickness : It was found that the weaves of woven fabrics for warmth had better use of satin weaves, Matt weaves, Granite weaves and Honey comb weaves. In the time of warmth is not the first purpose, had better use of Rib weaves. Plain weaves and Twill weaves with thin thickness and high thermal transmission.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.5
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• pp.127-136
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• 2011

This study was conducted on the field application for a method which is currently used. Although the method was performed with experimental knowledge, this study attempted to approach scientific ways through thirty sets of test-bed and three times monitoring limited by control variations for three months. The factors on previous studies are slope location, slope degree, type (roadfill vs. roadcut), aspect, vegetation cover, species, thickness, vertical length, horizontal length, soil type, elevation, erosion, soil-moisture, soil-hardness, pH, and so on. However, the factors of a suitable and significant level are slope degree, type, aspect, thickness, soil-moisture, vertical length and horizontal length in slope revegetation. the results were as follows : As a result of survey on soil types based on the status before construction, the rate of vegetation cover with non-mesh construction in soil areas was better than the rate of vegetation cover with fiber meshes and wire meshes. The rate of vegetation cover with fiber meshes in weathered rocks was better than using wire meshes. The rate of vegetation cover with the wire meshes in blasted rocks was better than using fiber meshes. Also, the factors affecting the rate of vegetation cover presented the number of appearance species, soil-moisture, thickness. this result presented the more appearance species as a positive role, and the lower soil-moisture and the thicker soil as a negative role.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.1
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• pp.58-66
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• 2022

In this study, to examine the effect of the transverse thermal expansion behavior of FRP reinforcing bars and concrete on the concrete cover thickness, based on 20℃, when the temperature changes from -70℃ to 80℃, the behavior of concrete was studied theoretically and numerically. Theoretical elastic analysis and nonlinear finite element analysis were performed on FRP reinforced concrete with different diameters and cover thicknesses of FRP reinforcement. As a result, at a negative temperature difference, concrete was compressed, and the theoretical strain result and the finite element result were similar, but at a positive temperature difference, tensile stress and further cracks occurred in the concrete, which was 1.2 to 1.4 times larger than the theoretical result. The ratio of the diameter of the FRP reinforcing bar to the thickness of the concrete cover (c/db) is closely related to the occurrence of cracks. Since the transverse thermal expansion coefficient of FRP reinforcing bars is three times greater than that of concrete, it is necessary to consider this in design.

• Journal of the Korean institute of surface engineering
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• v.52 no.6
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• pp.310-315
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• 2019

The use of a silicon carbide (SiC)-based composite ceramic layer for the mold of a curved cover glass was demonstrated. The stress of SiC/VDR/graphite-based mold structure was evaluated via finite element analysis. The results revealed that the maximum tensile stress primarly occured at the edge region. Moreover, the stress can be reduced by employing a relatively thick SiC coating layer and, therefore, layers of various thicknesses were deposited by means of chemical vapor deposition. During growth of the layer, the orientation of the facets comprising the SiC grain became dominant with additional intense SiC(220) and SiC(004). However, the roughness of the SiC layer increased with increasing thickness of the layer and. Hence, the thickness of the SiC layer needs to be adjusted by values lower than the tolerance band of the curved cover glass mold.

• Structural Engineering and Mechanics
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• v.36 no.4
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• pp.499-511
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• 2010

This paper examines the ice cover effects on the seismic response of concrete gravity dam-reservoir-foundation interaction systems subjected to a horizontal earthquake ground motion. ANSYS program is used for finite element modeling and analyzing the ice-dam-reservoir-foundation interaction system. The ice-dam-reservoir interaction system is considered by using the Lagrangian (displacementbased) fluid and solid-quadrilateral-isoparametric finite elements. The Sariyar concrete gravity dam in Turkey is selected as a numerical application. The east-west component of Erzincan earthquake, which occurred on 13 March 1992 in Erzincan, Turkey, is selected for the earthquake analysis of the dam. Dynamic analyses of the dam-reservoir-foundation interaction system are performed with and without ice cover separately. Parametric studies are done to show the effects of the variation of the length, thickness, elasticity modulus and density of the ice-cover on the seismic response of the dam. It is observed that the variations of the length, thickness, and elasticity modulus of the ice-cover influence the displacements and stresses of the coupled system considerably. Also, the variation of the density of the ice-cover cannot produce important effects on the seismic response of the dam.

• Journal of the Korea Concrete Institute
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• v.24 no.6
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• pp.761-768
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• 2012

The purpose of this study is to investigate bond properties of GFRP used in SFRC (Steel fiber reinforced concrete) and normal concrete. The experimental variables were rebar diameter (D13, D16), steel fiber volume fraction (0~2%) and cover thickness ($1.5d_b$, $5.4d_b$). The experimental results showed a different failure mode depending on the cover thickness. Through the tested specimens, splitting failure occurred for the specimens with small cover thickness and pull out failure occurred in the specimens with large cover thickness. Introduction of steel fiber caused the specimens to have more ductile behavior of bond stresss-lip after peak stress, but they did not increase the bond strength significantly. These failure modes were shown in both steel reinforcement and GFRP. However, from the difference of micro structure of bond failure mechanism between steel rebar and GFRP rebar, more ductile behavior was observed in GFRP-specimens after maximum bond strength was reached.

• Fibers and Polymers
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• v.4 no.4
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• pp.176-181
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• 2003

Theoretical weavability limit relationships of fabrics from regular warp yarns and fancy filling yams with thickness variation in shuttleless weaving are reviewed. The relationships correlate maximum warp and filling cover factors, warp and filling yarn characteristics, the distribution of thick and thin places of filling yarn over the fabric surface, and the warp and filling weave factor. The research considers single filling feeder and multiple feeders cases. Additionally, comparisons between the weavability limit of regular yarns and fancy yams in shuttle and shuttleless weaving are given.

• Journal of the Korean Society of Hazard Mitigation
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• v.7 no.4
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• pp.13-18
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• 2007

The research was performed to review the design factors which affect the durability of structures. For the study, domestic and foreign literature review were performed on various design criteria. Based on Korean standard specifications, the results showed that the durability of structure as the diameter of reinforcing steel bar becomes smaller and the distance between reinforcing bar is closer than the normal gap. The results were also presented that the minimum required bar cover is 6.6cm to obtain the durability index value. In addition, the maximum limited bar cover was 12cm considering the durability index and the change of increasing value of durability index. In case that there is no specified regulation for the bar cover thickness change, the durability life by neutralization is proportional to the thickness of bar cover.

• Explosives and Blasting
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• v.31 no.1
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• pp.33-40
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• 2013

Carinthian cut and cover tunnelling method which combines cut & cover and NATM tunnel excavation method has increased the interest. Design and construction of arch concrete have been increased, but there is no applicable standards for arch concrete. Therefore, in this study numerical analysis was performed to propose standards for the Carinthian tunnelling method considering a variety of conditions such as ground conditions, tunnel overburden thickness, thickness of backfill, and overburden surface slope angle changes, linear regression equations derived to classify and organize a rational, economical, and safe Carinthian cut and cover tunneling method based proposed.

• Journal of the Korea Concrete Institute
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• v.21 no.2
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• pp.153-158
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• 2009

Using non-invasive surface measurement method, the corrosion state of steel embedded inside concrete can be measured by placing four electrodes on the surface of concrete. Modeling of such measurements can provide valuable information as how interfacial impedance between corroded steel and surrounding concrete results in measured impedance on the concrete surface. In this paper, the modeling of surface measurement technique is used for the determination of the sensitivity of the measurements with respect to steel bar size embedded inside concrete and cover thickness. Modeling results indicated that steel bar sizes varied from D10 to D35 could be identified. Concrete cover thickness changes from 0.02 m to 0.1 m was also distinguished using the modeling scheme. The results confirm this modeling technique is capable of determining steel bar sizes and cover thickness, as well as simulating corrosion responses.