• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.563-566
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• 2005

Concrete structures have been damaged by salt, carbonization, freezing and thawing and the others. Therefore, it is needed to protect durability and performance according to the appropriate materials and methods in the concrete structures. In general, several types of polymer and silicate are used as protecting deterioration agents of concrete structures, but these agents have many problems because of low durability and properties. In this study, It developed the deterioration restraining agent using polycondensed silicate and monomer that can block a deterioration cause such as $CO_2$ gas, salt and water from the outside and enhance waterproofing ability by reinforcing the concrete surface when applying it to concrete structures. Also, it developed the systems for improving concrete performance using a deterioration restraining agent.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.54-57
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• 2003

Scaling deterioration of port concrete structures due to the combined effects of chemical actions by seawater and the freeze-thaw action is also a problem which has not yet been fundamentally solved. Furthermore, deterioration of concrete surface was considered as accelerate factor of concrete durability tended to decrease. Therefore, we considered the scaling measuring method and decreasing influence of durability of concrete according to kind of binders, such as OPC, Slag, Slag+Fa, due to freeze and haw of sea water. As a results of this study, it was effective method of scaling deterioration of concrete, and confirmed the salt deterioration resistance effect to use slag binder against to sea water.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.523-526
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• 2005

In order to traffic safety during winter season, snowfall and cold area has been spread the deicing chemicals, and the spraying amount is increasing every year. Use of deicing chemicals has been and will continue to be a major part of highway snow and ice control methods. Chloride-containing chemicals such as calcium chloride or rock salt are main deicers for the road. Extensive use of chloride deicers is, however, the source of substantial cost penalties due to their corrosive action and acceleration to deterioration concrete structures. Deterioration due to de-icer salt occurs in practice in concrete pavement, dike, barrier and similar structure. This paper reports the results of effect of de-icer salt on durability of concrete structure in winter. To protect concrete structure from damage by de-icer salt in winter, the exposure test was performed using three methods such as increase in design strength upto 32MPa application of granulated blast furnace slag powder, and concrete sealer. Of these, the method of increase in design strength upto 32MPa showed better durability for deterioration by de-icer salt.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.553-561
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• 2010

Like the shotcrete can be deteriorated by chemical compounds as service years increase, the grout which is used to fasten the cablebolt(rockbolt) system in the underground structures also can be deteriorated by chemical compounds such as sulphate and/or chloride contained in groundwater during service years. This can induce issues on the long term durability of cablebolt(rockbolt) system and consequently on the stability of underground structures. In this study, the deteriorations of long term durability of cement mortar grout by each chemical compound of sulphate or chloride are studied experimentally and also complex deterioration by the mix of sulphate and chloride is investigated. Based on the results obtained in this study, the characteristics and prediction of deterioration of long term durability of cement mortar grout for cablebolt(rockbolt) system are suggested.

• 콘크리트학회논문집
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• 제19권1호
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• pp.47-56
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• 2007

최근들어 고속도로, 고속철도, 지하철등의 건설이 증가하면서 터널의 건설도 늘어나고 있는 추세이다. 이러한 터널 공사에서 필수적으로 따르는 것이 숏크리트 공정이며 이러한 숏크리트의 시공은 앞으로도 더욱 증가할 추세에 있다. 그러나 숏크리트의 광범위한 시공에도 불구하고 여러 가지 문제점을 내포하고 있는 것이 사실이다. 따라서 본 연구에서는 우리나라 현행 숏크리트의 현황과 문제점을 분석하고, 고품질의 숏크리트 시공을 위하여 실리카퓸 숏크리트의 성능 및 적용성에 대해 분석하였다. 또한 숏크리트의 장기적인 안정성 확보를 위해서는 복합적인 환경조건을 고려한 열화 특성을 파악할 필요가 있다. 본 연구에서는 건습 반복, 동결융해 및 탄산화 등의 열화 인자를 복합적으로 적용한 열화 시험을 수행하였다. 특히, 우수한 강도 증진 효과로 국외에서 많이 사용되고 있는 실리카퓸을 적용하여 혼화재 치환에 따른 숏크리트의 장기 내구 특성을 평가하였다. 복합 열화 시험 결과 실리카퓸을 혼입한 숏크리트는 다른 배합에 비해 가장 양호한 결과를 나타냈고, 실리카퓸은 강도 증진 효과와 함께 강섬유 혼입에 의한 열화 현상을 최소한으로 감소시켜 숏크리트의 장기 내구성을 확보하는데 효과가 있었다.

• Corrosion Science and Technology
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• 제6권4호
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• pp.177-185
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• 2007

The purpose of this study is to evaluate freezing-thawing and surface scaling resistance in order to examine the frost durability of concrete in a chloride-inherent environment. The mixing design for this study is as follows: 3 water binder ratios of 0.37, 0.42, and 0.47; 2-ingredient type concrete (50% OPC concrete and 50% ground granulated blast-furnace slag), and 3-ingredient type concrete (50% OPC concrete, 15% fly ash, and 35% ground granulated blast-furnace slag). As found in this study, the decrease of durability was much more noticeable in combined deterioration through both salt damage and frost damage than in a single deterioration through either ofthese; when using blast-furnace slag in freezing-thawing seawater, the frost durability and surface deterioration resistance was evaluated as higher than when using OPC concrete. BF 50% concrete, especially, rather than BFS35%+FA15%, had a notable effect on resistance to chloride penetration and freezing/expansion. It has been confirmed that surface deterioration can be evaluated through a quantitative analysis of scaling, calculated from concrete's underwater weight and surface-dry weight as affected by the freezing-thawing of seawater.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.237-240
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• 2006

Almost 30 years have been passed since the first nuclear power plant was operated in Korea. Many studies have been actively conducted from the early 1990's in order to develop the deterioration management system for concrete structures in NPPs(Nuclear Power Plants) accordingly. Base on these studies, a systematic deterioration management program has developed and operated since 1997. According to this program, systematic inspections to provide database and evaluation were periodically performed (every overhaul at intervals of $12{\sim}18$ month and every five years). Accumulated deterioration database was usefully utilized for the NPP PSR (Periodic Safety Review). In this paper, the long-term durability and integrity of Kori 1,2 NPP concrete structures which are the oldest ones in Korea were evaluated based on the precise inspection database and regulatory inspection results including compressive strength, depth of carbonation, amount of chlorination and spontaneous potential of reinforcing bar, etc. It was noted that Kori 1,2 NPP structures have not any serious durability problems.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.547-550
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• 2005

Recently, there has been a intensive social interest for concrete structures with respect to durability by carbonation, chemical attack etc. Specially, the deterioration of concrete due to chemical attack in environments such as Wastewater Treatment Facilities is important factors degrading the durability of concrete structure. The purpose of this paper is to evaluate on deterioration of Wastewater Treatment Facilities concrete to chemical attack through instrumental analysis such as XRD, SEM and EDS. According to the results of this study. Wastewater Treatment Facilities concrete to chemical attack due to $So_{4}^{2-},\;Mg^{2+}$ ions founded out to appear deterioration materials peak : ettringite/thaumasite. gypsum and brucite peak.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.503-506
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• 2005

Recently, corrosion of reforcement of reinforced concrete structures and carbonation is raised problem of durability because of exhaustion of river sand and rapid increase of sea sand and also, concrete structure of sea environment is attacked to combined deterioration according to penetration of chloride ion and carbonation, change of temperature, repetition of dryness and wetness. Therefore, In this study, data base were presented to solve the problem about using sea sand to concrete structure situated in combined deterioration environment by exposuring concrete specimen contained chloride ion under the individual and combined deterioration.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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• pp.597-600
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• 2006

In Marine Land underground reinforced concrete structures, such as electric box power structure, water and chloride ion penetrated into concrete through the cracks of concrete and its permeable property, cause the corrosion of reinforcing steel bar, which accelerates the expansive cracks and deterioration of concrete. The purpose of this paper is to evaluate on deterioration of durability concrete through instrumental analysis such as schmidt hammer and carbonation, chloride content. Under the reclaimed marine land, the main cause of deterioration of concrete structures is the steel corrosion due to the penetration of chlorides and the deterioration of outer concrete itself by chemical attack.