• Proceedings of the Materials Research Society of Korea Conference
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• 1996.05a
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• pp.35-35
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• 1996

• Proceedings of the Materials Research Society of Korea Conference
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• 1996.05a
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• pp.122-122
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• 1996

• Proceedings of the Materials Research Society of Korea Conference
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• 1993.05a
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• pp.144-144
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• 1993

• Proceedings of the Materials Research Society of Korea Conference
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• 1997.05a
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• pp.107-107
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• 1997

• Proceedings of the Materials Research Society of Korea Conference
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• 1997.05a
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• pp.108-108
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• 1997

• Proceedings of the Materials Research Society of Korea Conference
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• 1998.11a
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• pp.28-28
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• 1998

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.5
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• pp.148-155
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• 2017

In this study, by using the international standards ISO TS 16774, Part 2 Test method for chemical resistance as a quality control method of injection type repair material used for leakage crack of underground concrete structure, the performance requirement against of chemical environment of underground concrete structures for repair materials was tested. For this testing 3 types for each of the 2 classes of repair materials(synthetic rubber, cement), with a total of 9 types repair materials, were selected and examined. As a result, the test results showed that the smallest performance deterioration by the change in the mass was with the synthetic rubber(RG) type as opposed to the cement type system, showing that the synthetic rubber type had the strongest relative resistance to chemical exposure. Furthermore, it is necessary to investigate the material with high resistance to chemical substances and to examine the material which can increase resistance to sodium hydroxide and sodium chloride in cement system. These results can be used as a basic index for the selection of repair materials with the strongest resistance to chemical environment found in concrete structures. In addition, it is expected that the test results derived in this study can be used as reference data that can be reflected in the quality improvement of the maintenance material to be developed later.

• Journal of the Korean GEO-environmental Society
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• v.10 no.2
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• pp.21-28
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• 2009

A grouting method has been widely used in construction of large-scale structure to reduce permeability and reinforce the ground. If cement and grout material were not mixed well in the injection tip equipment, an opposite flow and interception state of the chemical grouting can occur. McG (Multi-mixing counterflow prevented Grouting, McG) method installed a special grouting device to allow better mixing of the grouting material(above fineness $6,000cm^2/g$) and prevent backward flow. The block of nozzle also diversify powder rate of cement. YSS (Youngil Special Silicate, YSS) that lowers $Na_2O$ and thereby increases durability was developed by gel-forming reaction material. The seepage state and unconfined compressive strength of the injection material using the special injection tip equipment was tested in this study. The results of this study showed that the uniaxial compressive strength, permeability, N-value, TCR and RQD were improved by this method. Engineering characteristics obtained by the special injection tip method will be compared with those by the other method through various field tests from now on.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.118-119
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• 2014

원전 운전 중 2차계통 구성재료가 부식되어 철 산화물이 증기발생기 내부로 유입된다. 유입된 철산화물은 고온고압의 환경에서 침적되어 슬러지가 된다. 침적된 슬러지는 증기발생기 전열관 재료에 응력부식균열(SCC)을 일으키는 주원인으로 원전에서는 철 산화물의 유입을 최소화하기 위해 기동전 2차계통을 순환 세정하고 있다. 해외 원전에서는 고분자 아크릴산(Polyacrylic Acid)을 순환세정시 주입함으로써 2차계통 철 산화물 제거 효율을 높인 사례가 있었다. 이에 우리 원전에서도 기동전 순환세정시 고분자 아크릴산을 주입 적용하였다. 고분자 아크릴산 주입 전 필수적으로 이뤄져야할 연구는 고분자 아크릴산이 재료에 미치는 영향평가이다. 본 연구에서는 고분자 아크릴산 농도(1, 10, 100 ppm)에 따라 2차계통 구성재료인 SA106 Gr.B와 Alloy 690의 건전성에 미치는 영향를 수행하였다. 평가방법으로는 전기화학 분극실험, 시편을 침지시켜 실험 전, 후 무게 감량을 이용한 부식률 측정, 표면 상태분석등을 이용하여 종합적으로 평가하였다. 전기화학 분극실험과 부식률 측정결과, 고분자 아크릴산 농도가 높을수록 부식은 증가하였고 고분자 아크릴산 농도 100 ppm일 때 최대 부식률이 0.037 mils로 계산되었다. 이는 부식허용 기준치(5.8 mils)보다는 100배이상 낮았으며 표면분석 결과 고분자 아크릴산으로 인한 pitting 부식은 발생하지 않았다. 이와 같은 결과로 기동시 환경에서 고분자 아크릴산 농도 100 ppm까지는 재료 건전성에 미치는 영향은 거의 없는 것으로 판단된다.

• Resources Recycling
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• v.33 no.1
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• pp.37-47
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• 2024

In grouting, the LW method is commonly employed to induce the gelation of cementitious material using water glass, thereby restricting the extent of material injection. Nevertheless, challenges manifest when materials are lost before gelation, particularly in regions with high groundwater flow rates or significant subsurface voids. This study developed a thixotropic grout material using LFS and GGBFS to mitigate material loss during injection, with an assessment of its flow characteristics, durability in marine exposure, strength, and injection properties. The outcomes revealed that the thixotropic grout material exhibited flow ranging from 105 to 143 mm and enhanced strength and durability compared to the LW method. Furthermore, field tests substantiated that applying vibration and impact improved impermeability.