• Magazine of the Korean Society of Agricultural Engineers
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• v.45 no.7
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• pp.20-26
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• 2003

The ultra-lightweight high strength polymer concrete could be used for the drain structures under severe condition. In this study, materials used were unsaturated polyester resin, heavy calcium carbonate, artificial lightweight coarse aggregate and perlite. In the test results, the unit weight of the ultra-lightweight high strength polymer concrete was 946 kg f/$\textrm{m}^3$ and the compressive strength was appeared in 34.5 MPa. The compressive strength, splitting tensile strength, flexural strength, acid resistance and weather resistance were shown in excellently than that of the normal cement concrete. The draining trench had 1m length, 0.24 m width, 0.02 m thickness and 0.07 m height. The developed trench could be effectively used at the draining structures.

• Journal of Ocean Engineering and Technology
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• v.19 no.2 s.63
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• pp.90-93
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• 2005

An improved approximate formula is presented for Series 60 forms, modifying the approximate formula, developed by the Author in 1983. The weather formula is based on interpretations of detailed calculations of speed loss, due to wind(van Berlekom), motions(Maruo), and wave reflection resistance(Kwon). Comparison is made between the result of the approximate formula and the one of detailed calculation. The result of the formula is also compared with some published full-scale data for speed loss.

• Journal of Ocean Engineering and Technology
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• v.18 no.3
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• pp.40-43
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• 2004

A rational method is presented for estimating the power increase of a ship at sea. A probabilistic approach is applied to determine the weather condition at sea, A comparison is made between some full-scale data and the result of Swift's method. A comparison is also made to find differences among the results of eight kind methods for the wind added resistance of a VLCC in head wind. The mean difference between the results is 7％, in general, for a given relative wind speed.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.221-222
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• 2023

In this study, the performance evaluation of waterproof sealant materials applied to the outer wall of PC apartment houses was conducted. The sealant for PC members must have resistance to movement, and since it is exposed to outside air, weather resistance and water resistance are required.

• Computers and Concrete
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• v.17 no.4
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• pp.541-551
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• 2016

Asphalt pavements are exposed to complex weather conditions and vehicle traffic loads leading to crack initiation and crack propagation in asphalt pavements. This paper presents the impact of weather conditions on fracture toughness of an asphalt concrete, prevalently employed in Ardabil road networks, under tensile (mode I) and shear (mode II) loading. An improved semi-circular bend (SCB) specimen was employed to carry out the fracture experiments. These experiments were performed in two different weather conditions namely fixed and cyclic temperatures. The results showed that consideration of the impact of temperature cycling resulted in decreasing the fracture toughness of asphalt concrete significantly. Furthermore, the fracture toughness was highly affected by loading mode for the both fixed and cyclic temperature conditions studied in this paper. In addition, it was found that the MTS criterion correctly predicts the onset of fracture initiation although this prediction was slightly conservative.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.1 s.139
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• pp.57-63
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• 2005

This paper introduces basic research of optimum routing assessment system as voyage support purpose which can obtain safe and efficient route. In view point of safety, the prediction of ship motion should be evaluated in the condition of rough weather This part includes general seakeeping estimation based on 3 dimensional panel method and parametric roil prediction. For increasing voyage efficiency, ETA(Estimated Time of Arrival) and fuel consumption should be calculated considering speed reduction and power increase due to wave effects based on added resistance calculation and ship performance characteristics. Basically, the weather forecast is assumed to be prepared previously to operate this system. The idea of these factors in this system will be helpful to escape from dangerous voyage situation by wave conditions and to make optimum route planning based on ETA and fuel consumption.

• Journal of the Korean Wood Science and Technology
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• v.34 no.5
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• pp.88-97
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• 2006

Wood flour (WF)-recycled polypropylene (RPP) composites composed of 50% WF of Eucalyptus deglupta Blume species, 50% RPP, various contents of maleic anhydride (MAH) modifier (0; 1; 2; 5; 5; 7.5; and lo%), and 15% dicumyl peroxide (DCP) initiator (based on MAH weight) were subjected to weather for 1 year and subterranean termite (Coptotermes cuwignathus HOLMGREN) and dry wood termite (Cryptotermes cynocephalus LIGHT) for 3 and 4 weeks, respectively. WF-RPP composites with 2.5% MA modifier had tensile strength, breaking elongation and Young's modulus about 2.2, 2.3, and 1.2 times, respectively higher compared to MAH-free composites. The WF-RPP composites with or without MAH modifier had 5.5 times higher resistance to weather compared to RPP film alone. The color of the WF-RPP composites with or without MAH modifier became lighter after exposures to the weather. The WF-RPP composites with or without MAH modifier are resistant to subterranean termite Coptotermes curvignathus HOLMGREN and dry wood termite Cryptotermecs cynocephalus LIGHT under the experimental condition adopted.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.233-236
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• 2003

This study is intended to investigate the resistance of frost damage of concrete for planting, which recycled aggregate is used, by freezing in air and thawing in water. According to the results, if AE agent of 0.005% is mixed in making concrete for planting, it is thought that the resistance of frost damage is guaranteed in winter because concrete for planting is not under severe freezing and thawing function, but under natural weather action.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.11c
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• pp.39-55
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• 1999

Geotextile composites to improve the weather ability were composed of recycled polyester geotextile with carbon black as ultraviolet stabilizer and polypropylene geotextile by needle-punching method, and evaluated physical properties, ultraviolet resistance and chemical stability. Retention ratio of tensile properties of non woven polypropylene geotextiles were decreased about 50% by the exposed condition with ultraviolet but those of geotextile composites were slightly decreased than polypropylene geotextiles. Geotextile composites which have larger weights of polyester geotextile were more stable against ultraviolet. For chemical stability, the changes of tensile properties of geotextile composites were in the range of -20~＋10% at the various chemical conditions.

• Proceedings of the KSR Conference
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• 2002.10a
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• pp.684-689
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• 2002

This paper represents the life-cycle cost(LCC) of steel bridges which are located on the train-network. Corrosion problems are mainly considered in the steel members such as steel plate girder, box girder, truss and arch. Based on the current value, initial construction cost, maintenance cost and demolition cost are calculated and life-cycle costs are formulated for the several types of bridges. From the comparison on each LCC, an effective painting method is recommended for reducing the LCC of steel bridges. Even though the initial cost of Super Weather Resistance Heavy Duty Paintings (Resin Fluoride) is expensive, because of the long endurance, the LCC of steel bridges painted with Super Weather Resistance Heavy Duty Paintings (Resin Fluoride) is less than that painted with General Heavy Duty (Rubber Chloride).