• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.3
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• pp.116-124
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• 2014

Penetration depth of inorganic waterproofing agent is difficult to assess quantitatively because inorganic waterproofing agent for concrete is not an internal waterproof membrane. However, evaluation of penetration depth of inorganic waterproofing agent is one of the most important evaluation index to secure efficiency in a consistent penetration. Therefore, this paper was proposed penetration depth measurement method of inorganic waterproofing agent for concrete and the penetration depth of the conventional inorganic waterproofing agent have been evaluated through the proposed penetration depth measurement method. As a result of test, the measured penetration depth throught the proposed penetration depth measurement method of inorganic waterproofing agent showed that more than 90% reliability.

• Journal of the Korea Concrete Institute
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• v.20 no.3
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• pp.283-290
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• 2008

The repair technique using surface impregnation of reactive compound is so effective for deteriorated concrete structures that many researches are recently focused on these works. Particularly, inorganic impregnant is regarded as ecofriendly material because there is no air-pollution during manufacturing process as well as field coating works. Furthermore, The delamination between old concrete and impregnated surface does not occur, resulting from different material characteristics. In order to evaluate the durability performance of surface-impregnated concrete, durability evaluation through the long-term exposure tests is significant, however, experiments are usually limited to the temporary and qualitative laboratorial scope. In this study, durability characteristics for inorganic and organic/inorganic impregnated concrete specimens are evaluated through longterm chloride exposure test. The specimens with 21MPa and 34MPa strength have been prepared and exposed to chloride attack in the atmospheric, tidal, and submerged conditions. Evaluation for compressive strength, chloride penetration, and electrical potential (half cell potential) for steel corrosion are performed for the specimens exposed for 2 years. From the results, no distinct strength gaining is observed but the resistance to chloride penetration and steel corrosion is evaluated to be improved through surface impregnation. The more improved resistance to chloride attack is measured in the inorganic impregnated concrete and the results from atmospheric condition show more improved resistance to chloride attack than those from submerged and tidal condition.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.1
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• pp.71-77
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• 2010

The concrete structure's durability and integrity is reduced owing to various deterioration phenomena. Therefore, it is important to prevent the deterioration phenomena. This study inquired into the various experimental results of specimens with different dilution concentration and impregnation time by the each solution to present the economic and efficient using method of the inorganic surface penetration agents. As a results, the reasonable dilution concentration and impregnation time of colloidal silica solutions are 15% and 5 minute and for the sodium alumina silicate solutions are 17% and 10 second.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.6
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• pp.77-86
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• 2007

The repair technique utilizing surface impregnant is widely used due to its simple construction procedures and economical benefit. Surface protection through this reparing technique cannot increase the bearing capacity of concrete members much but increase the durability performance and service life efficiently. In this study, fundamental tests such as water suction and permeation are performed for concrete specimens with several organic/inorgarnic impregnant and suitable impregnant is selected on the basis of the results. Finally, durability tests such as carbonation, freezing and thawing, and chloride attack are carried out for the concrete specimens with selected impregnant and it is experimentally verified that they have good resistance to deteriorations.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.1
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• pp.71-84
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• 1992

Polymer-Impregnated Concrete(PIC) is a composite material of concrete and polymer. PIC has superior properties compared to conventional cement concrete, such as strength, stiffness, toughness, durability, water-proofing, chemical resistance. However, the usage of PIC has been limited to repairing materials and non-structural applications due to the lack of the design criteria and the analytical model to determine structural behavior. The objective of this study is experimentally to develop the optimum mixing proportions of polymer impregnants and the stress-strain responses, the strength characteristics, the fatigue and creep behaviors, and the durabilities of MMA(methyl methacrylate)-based PIC.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.4
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• pp.79-88
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• 2007

Concrete structures undergo degradation of durability performance and it generally propagates to the structural problems. Recently. a lot of materials for surface protection for concrete are developed, however, performance is not clearly improved due to the difficulties such as repair construction technique and quality of materials for repairing. In this study, liquid inorganic impregnant for concrete structures is developed and durability performance for impregnated concrete specimens is carried out. Furthermore, the performances of the concrete specimens with developed impregnant is also compared with those of the specimens with impregnant conventionally used. Additional CSH gel is formed through the reaction of calcium hydroxide ($Ca(OH)_2$) and impregnant with silicate. As a result of the reaction, impregnated concrete is evaluated to have more denser surface and resistance to deterioration. Finally it is experimentally verified that the concrete specimens with developed impregnant show better durability performance than normal specimens and those with conventional impregnant.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.453-456
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• 2006

If cement can be manufactured with industrial byproducts such as granulated blast furnace slag(GBFS), phosphogypsum(PG), and waste lime(WL) instead of clinker as its counterproposal, there would be many advantages, including maximum use of these industrial byproducts for high value-added resources, conservation of natural resources and energy by omitting the use of clinker, minimized environmental pollution problems caused by CO2 discharge, and reduction of the production cost. This research investigates the chloride ion permeability of NSC concrete added PG and WL to GBFS as sulfate and alkali activators. The result of experiment of chloride ion permeability, showed that NSC is very excellent in seawater resistance. Such a reasons are that the hydrate like CSH gel and ettringite formed dense pore structure of NSC matrix.

• Journal of the Korea institute for structural maintenance and inspection
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• v.9 no.4
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• pp.177-186
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• 2005

The latest concrete structure has showed that the deterioration of durability has been increased by the damage from salt, carbonization, freezing & thawing and the others. Therefore, the measures for the concrete which has deteriorated durability have been taken. Among them, it has been often used that surface treatment which cuts off the deterioration factors of durability by protecting the surface of concrete. However, troubles such as fracture and rupture in the repair layer have been reported as time goes by due to the difference between the organic repair material like epoxy and concrete properties. Researchers have been developing the repair material which can cut off the deterioration factors of durability such as $CO_2$ gas, chloride ion and water by making the formation of concrete elaborate through the reaction with calcium ion when the surface improving agent is coated on the concrete. The main ingredient of that is inorganic substance which is the same as the concrete property. This study was evaluated the surface improving agent for permeability, watertightness, air-permeability, chemical resistance and elution resistance. As a result, it has been reported that the surface improving agent improves watertightness and air-permeability by penetration more than 10mm within concrete. Therefore, it is concluded that the surface improving agent developed in this research prevents deterioration of concrete durability when it is coated on the concrete structure.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.1
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• pp.56-63
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• 2016

This experiment was compared and analyzed between the original surface paint through chloride penetration, neutralization, freeze-thaw and chemical corrosion resistance measuring internal structure and volume of voids in order to evaluate the effect of increase in durability of the newly modeled nano synthesized polymer paint painted on concrete surface which results improvement on air permeability to increase the durability of concrete structures. The test result of measuring volume of void and inner structure, concrete, spreaded with nano synthesized polymer paint, showed decreasing trend of pore volume in the range of less than $0.1{\mu}m$ and more than $0.3{\mu}m$. Also, using an electron microscope inside showed tightness of hydration texture. Chloride penetration depth of concrete, painted with nano synthesized polymer paint, was decreased more than 92% compared to non-painted concrete and 70% with water-based epoxy painted concrete. Especially, chemical corrosion resistance test set with aqueous solution of 5% sulfuric acid, non-painted concrete and water-based epoxy painted concrete showed weight loss of 4% after dipping for 12 days. On the other hand, concrete painted with nano synthesized polymer paint showed 1.7% weight loss under the same condition. Also, it showed great result of appearance under the criteria of Tsivilis et al.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2000.11a
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• pp.132-132
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• 2000

환경오염과 이상기후의 영향으로 인한 수자원의 고갈과 함께 국내의 경우 수자원 개발 계획 및 수요량을 감안할 때 향후 7 년 내에 물부족 현상을 겪을 것이라는 보고가 있 었으며, 환경부담을 줄이기 위해 폐수의 배출기준은 강화되고 있다. 이러한 상황에서 제조 특성상 타 업종에 비해 폐수 발생량이 높은 편인 국내의 제지산업은 여러 해전부터 이에 대 한 방안을 모색하여 왔다. 일반적으로 폐수 수질 관리와 청수 사용량의 절감을 위해 고가의 폐수 처리 장치를 설치하거나 폐수 재활용을 통해 공정을 극도로 폐쇄화하는 방안으로 연구 가 진행되어 왔다. 이 중 용수의 재활용이 가장 경제적인 방법이지만, 재활용이 지속될수록 각종 무기염과 콜로이드성 유기물질이 축적되어 각종 약품의 효능 저하, 탈수속도의 저하 및 생산 제품의 품질 악화 등의 문제를 유발한다고 알려져 있다. 이를 해결하고자 하는 노 력으로 펄프 원료에 따른 공정수 내 용해성 물질의 분석과 재활용 횟수에 따른 각종 SS와 D DS의 축적 정도에 대한 기초 연구가 수행되었으며, 고폐쇄화된 공정에서 성능을 발휘할 수 있는 첨가제의 개발과 적용 방법에 대한 연구도 수행된 바 있다.여러 지종 가운데 골판지 원지는 용수의 재활용률이 상당히 높은 지종이기 때문에 공정수의 재활용이 진행될수록 열악한 저급 원료로부터 각종의 다양한 물질이 용출 혹은 배 출되며, 이러한‘물질은 골판지 원지의 강도 발현에 더욱 악영향을 미칠 것으로 판단되었다. 미세분으로 구성된 SS의 경우 이미 많은 연구를 통해 특성이 파악되었기 때문에 본 연구에 서는 ss를 제외한 공정수를 두 가지로 크게 나누어 고려하였다. 즉, ss로 측정되지 않지만 닥도를 유발할 수 있는 미세 무기물질과, 용해성의 무기염, 첨가제 및 추출물 둥으로 이루어 진 용해성 성분으로 나누어 분석하였으며, 또한 각각이 초지 특성에 미치는 영향을 살펴보 고자 하였다.을 해석코자 하였으며, 그 방법으 로 수치해석기법을 도입하였다. 또 실제 캘린더링 전후의 두께 변화를 측정하여 유리전이온도 의 도달 깊이와 비교하였다. 지필의 압축 정도는 롤의 직경과 닙 폭을 이용하여 MD 방향으 로 함수화하였으며, 열전달 계수로는 겉보기 값을 사용하였다. 이때 지펼은 균질한 것으로 가 정하였다. 함수율은 유리전이온도를 좌우하는 가장 큰 인자이나 본 연구에서는 항온항습처리 를 통해 유입지의 함수율을 고정시켰으며 캘린더링 시 함수율의 변이는 없다고 가정하였다. 그 결과 열침투깊이가 증가할수록 지필은 보다 변형되기 쉬운 상태가 되어 주어진 압력 조건에 대해 소성변형 정도가 증가하는 것으로 나타났다. 이는 캘린더링 전후에 두께 변화를 측정하여 정량적으로 평가할 수 있었다. 수치해석기법을 통해 같은 압력 조건에서 온도가 증 가함에 따라 혹은 같은 온도 조건에서 압력이 증가함에 따라 지필 내의 유리전이온도의 침투 깊이가 증가함을 알 수 있었으며 이는 캘린더링 전후의 두께 변화의 측정 결과와 일치하였 다. 또 NRT가 증가함에 따라서도 유리전이온도 침투 깊이가 증가하였다.합편에 비해 일부 우수한 양상을 보였지만 본 실험의 범위내에서는 통계적 정량적 차이를 제시할 수는 없었다. 향후 보다 광범위한 동물 실험이 필요할 것으로 사료된다.된다.하고도 완전교정술 도달 확률이 높은 치료전략이라는 사실을 입증하였으며 주대동맥폐동맥혈관부행지의 크기나 숫자가 단일화하기 쉬운 형태학적 특징을 지닌 경우에는 조기에 일단계완전교정술을 시행하여 양호한 결과를 얻을 수 있다는 사실을 발견하였다. 반면 본 환아군 중 단일화술을 먼저 시도한 군에서는 비록 단계적인 단일화를 시도한 군에서 단일화술과 관계된 수술사망율이 약간 낮기는 하였으나 완전교정술까지 완료될 가능성에는 차이가 없었다. 그러나 이 경우 보다 정련된 적응 환자의 선택을 통한 단일화 우선전략의 시도와 장기 추