• Journal of the Korea Institute of Building Construction
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• 제21권6호
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• pp.593-604
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• 2021

In this study, a comparative test was conducted on a specially developed elastic waterproof paint and general water-based paint for the purpose of responding to cracks occurring on the outer wall of concrete structures and improving watertightness. Through the comparative experiment, it was confirmed that the watertightness could be improved by securing the crack shielding property, and it was also confirmed that about 10 times more crack responsiveness was secured compared to general water-based paint. In addition, it was confirmed that the adhesion performance of at least 1.3MPa and resistance to a water permeation pressure of 0.1MPa were possible, confirming that stability was secured from a waterproofing perspective.

• Journal of the Korea institute for structural maintenance and inspection
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• 제27권2호
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• pp.1-7
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• 2023

Durability was evaluated by performing a full-scale vertical load fatigue test and a wheel load performance test on the HRS, which reduces the replacement time of the existing expansion joint and improves serviceability to allow partial replacement by lane. As a result of the vertical load fatigue test, the maximum stress of the rail-type expansion joint is 170 MPa, which is about 47.8% of the yield strength of the HRS expansion joint rail 355 MPa. The vertical load fatigue test of the HRS expansion joint with improved serviceability set the size and load of the load plate according to the road bridge design standards, did not show any fracture behavior in the vertical load fatigue test and the wheel load performance test 2 million times, and its durability and safety were verified.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제17권10호
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• pp.27-33
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• 2016

Military textiles with breathable waterproof materials are expanding as form of winter clothes. Waterproof moisture-permeable clothes are very important for soldiers to survive in cold weather operations because they prevent loss of body heat from the penetration of water into the human body. Korea military uses the water resistance and moisture permeability to test the performance of waterproof moisture-permeable materials. Moisture permeability is measured according to the amount of evaporated water vapor passing through a fabric under specified temperature and humidity by using acetic acid potassium presented in KS K 0594. However, the test procedure for measuring the moisture permeability in the standard is presented only briefly and the preparation procedures for the test in accredited testing institutions are applied differently, leading to significant deviation of the results. This paper compares the procedures of testing institutions and examines the factors that affect moisture permeability. Finally, we propose a procedure to reduce the deviation of results and apply the proposed procedure in testing institutions. Our analysis results with one-way ANOVA under significant level (0.05) confirm that the deviation of results is reduced.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제18권9호
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• pp.92-100
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• 2017

The Helicopter MRA Control Rod System has the important function of controlling the speed, height, and direction of helicoptersby adjusting the main rotor disc. However, the ingress of water into the inner control rod can cause ice damage in the rod during winter operation and also corrosion;these defects need to be rectified. The water flowed into the control rod through the upper side space, and the rod was cracked during icing expansion occurring at low temperature. The corrosion occurred due to the lack of coating process during the manufacturing process. To resolve these problems, the upper rod was sealed to prevent water inflow and a coating process was added to prevent corrosion. These solutions were verified by awaterproof test and a salt fog test. The phenomena, causes and measures were reviewed and the methods of improvement were established and proven. This proposed technology to prevent water infiltration and corrosion will contribute to the safety of rotary wing aircraft.

• YAKHAK HOEJI
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• 제1권1호
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• pp.9-12
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• 1948

한약시장에 나오는 생약중 그 일부(식물성생약 175종)는 1942년 조선약학회잡지 제23권 제1호에 각창씨명의로 발표되었으나 제일중시되는 각국약국방수재품, 급기외누락된것이 있으므로 이를 보충코저 시행한 식물성생약 50종의 일반시험성적을 보고코저한다.

• Journal of the Korea Institute of Building Construction
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• 제12권1호
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• pp.1-9
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• 2012

This study aims to propose a performance metric for the application of a horizontal air-exhausting system to be used for the reduction of vapor and/or moisture that exists in the waterproof layer, by evaluating the physical properties. For this reason, tests in accordance with current standards were carried out, and the results were examined. Finally, a proposal was established for a general performance metric that could be applied as fundamental data based on the user's judgment. This has some limitations, in that the object is existing merchandise, however it should be useful for application in the construction field. In the future, analysis of a wider area, including workability, should be added in the phase of field application.

• Proceedings of the Korean Institute of Building Construction Conference
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• 한국건축시공학회 2023년도 봄 학술논문 발표대회
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• pp.41-42
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• 2023

Test results for a total of four types of complex waterproofing methods were analyzed. In the case of the A method, the stress generated by high-viscosity compounds adhering to the base test body during the behavior of the test body was transferred to the sheet surface layer. In the case of the B method and the C method, the properties of the waterproof sheet consisting of a non-hardened seal based and a non-hardened seal are well reflected and stress absorption in the non-hardened seal layer acts strongly, rapidly reducing stress transfer to the surface of the waterproof sheet. In the case of the D method, slip occurs due to repeated behavior, and the stress on the attachment surface is reduced, and the stress transfer to the surface is greatly reduced. As a result, four types of composite waterproofing methods resulted in changing the stress transfer mechanism caused by behavior on the concrete surface due to the physical properties of the internal constituent material of the waterproof sheet.

• International Journal of Highway Engineering
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• 제14권2호
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• pp.1-10
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• 2012

As old concrete pavements of over 20years in age are increasing in expressways, the repair and rehabilitation of concrete pavement have become an important issue. Although asphalt overlay is widely used as an alternative to rehabilitate the old concrete pavement, problems due to infiltrated water such as reflection crack and pothole are imposing a very serious threat to its performance. This study proposes waterproof membrane as a solution to minimize the damage due to reflection crack and infiltrated water, and accelerated pavement testing was carried out for the performance comparison of composite pavement with waterproof membrane and ordinary tack coating. The experiment used water spraying to simulate rainfall, and the behavior and moisture resistance characteristics of overlay pavement were analyzed. The experimental result indicated that the strain pattern of waterproof membrane section differed from ordinary tack coating section because waterproof membrane caused the asphalt pavement and concrete pavement to move together. Additionally, since waterproof membrane minimized the infiltration of water and delayed the occurrence of reflection crack by about 70% in comparison to ordinary tack coating method. Moreover, the damage due to infiltrated water also decreased.

• Journal of the Korea institute for structural maintenance and inspection
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• 제20권2호
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• pp.60-66
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• 2016

Polyurethane foam index a of the cell structure and the absorption change by using the foam stabilizer of six to investigate the polyurethane foam index producing the agent to the siloxane analyzed with silicon foam stabilizer with FE-SEM in accordance with the characteristics of the silicon-based foam stabilizer cell structure of the primary DC-193 on the chain ends is PO n dog bond, DC-2585, DC-5125, DC-198 has been confirmed as a close cell, silicone surfactant is combined EO n dog to a siloxane main chain terminus DC-5043 and DC-5598 that appeared to open cell structure. In addition, most absorption of the DC-5043 appeared was the size of the open cell greatest formed by the absorption of the cell structure change this absorption of the size of the close cell most detailed and uniform DC-193 appeared small household water-resistant best many showed. The performance test of the water was found to be excellent.

• Journal of the Society of Disaster Information
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• 제15권2호
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• pp.214-222
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• 2019

Purpose: The purpose of this study is to develop a sprinkler head that can be controlled and initial suppressed by installing it in a rack-type warehouse. Method: Considering the spray radius and spray pattern, various deflectors were designed, and the spray angle, discharge characteristics and protection performance test was conducted, and these results were compared and analyzed. Results: An optimal sprinkler head was developed to protect full load, front side of a commodity with minimum water volume 115L/min. Conclusion: The developed head of K-115 and 1Bar pressure was tested with one tier storage confirming that the fire control is carried out without burning all the loadings. In addition, the vertical distance from the top of the load to the deflector shall be separated by 450mm and installed to allow sufficient discharge to the outer part of the commodity.