• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.574-577
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• 2006

Recently, the deterioration due to salt damage and carbonation as the main factors of deteriaoration of the domestic reinforced concrete structures has been increased. Also the national and social concern about the durability recovery of the deteriorated reinforced concrete structures is geratly being raised. Therefore, it is the final purposes of this study to develop the performance evaluation technique for durability of reinforced concrete structures deteriorated due to salt damage and carbonation with the proposal of the service life prediction method for the investigation and diagnosis of reinforced concrete structures, and accelerated test in Lab.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.237-240
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• 2006

The corrosion of steel reinforcing bar has been the major cause of the reinforced concrete deterioration. GFRP(Glass Fiber-Reinforced Polymer) reinforcing bar has emerged as one of the most promising and affordable solutions to the corrosion problems of steel reinforcement in structural concrete. However, GFRP rebar is prone to deteriorate due to other degradation mechanisms than those for steel. The high alkalinity of concrete, for instance, is a possible degradation source. This paper presents the long-term deterioration of the GFRP rebar under alkali environmental condition.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.321-324
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• 2006

The latest concrete has showed that the deterioration of durability has been increased by the damage from salt, carbonation, freezing & 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 CO2 gas, salt and water from the outside and enhance waterproofing ability by reinforcing the concrete surface when applying it to concrete structures. Also, it evaluated improving concrete performance using a deterioration restraining agent.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.417-418
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• 2009

As iron corrosion by means of penetration of chlorides resulted in a serious deterioration of seaside and landfill concrete construction, it is urgently necessary for seaside construction to acquire watertightness and resistance for chloride-attack. Hence in this study, Si/Al liquor type hybrid-inorganic salt which was very effective compound for improving resistance for chloride-attack applied to mortar and then evaluated resistance for chloride-attack with curing(7, 14, 28, 56 days).

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.797-800
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• 2008

The pre-mixed concrete shotcrete, which can pre-bag the shotcrete materials and thus can save considerable labor activity, will be developed through extensive experiments. The proposed pre-mixed High performance Shooting concrete system included hydro-demolition will be verified though field tests in actual repair and rehabilitation construction sites. This research was on developing of the High performance Shooting concrete by evaluation of site application by field test using new automatic Hydro-demolition and Shotcrete equipment.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.86-89
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• 2003

It is recognized that reinforcement corrosion is the main distress behind the present concern regarding concrete durability. In this study, to confirm corrosion of reinforced concrete affected by thickness of cover, kinds of surface coating, measured electric potential, ratio of corrosion area, weight reduction, corrosion velocity of steel bar under environment of complex deterioration. The results showed that an increase in age also increases corrosion of steel bar. Ratio of corrosion area is largely related to ratio of weight reduction. as well, corrosion of steel bar by thickness of cover is superior to l0mm thick than 20mm thick. It showed that an increase in thickness of cover prevent steel bar from deteriorating. The results of this study showed that corrosion velocity was affected by thickness of cover, kinds of surface coating. data on the development of corrosion velocity made with none, organic B, organic A, inorganic B, and inorganic A is shown.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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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.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.307-312
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• 1997

The sea water resistance of cement and concrete must be compared when it used for construction in the ocean. The sea water resistance of the concrete specimens using three types of cements such as ordinary Portland cement, sulfate resistance Portland cement, blastfurnace slag cement were studied. In this study, an accelerated test for access sea water resistance by subjecting the concrete specimens to repeated cycles of concentrated sea water immersion and hot wind drying was employed. This study proved that sulfate resistance Portland cement had higher resistance for sea water.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.169-174
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• 2003

The purpose of this study is examine into the application of infrared thermography for voids detect in reinforced concrete structures. In this study, the experiments were carried out for analyze the effect of void size, cover, measurement time and distance on test piece which has artificial voids. Results of this study are as follows. Noiseless and high resolution thermography was acquired 11:00 - 14:00 and the thermography which taken 16:00 was not suitable for void detection. The difference of temperature between voids and solid to identification the existence of voids by eye is $0.3^{\circ}C$.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1507-1508
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• 2015

콘크리트 배전전주는 시간의 경과에 따라 열화현상이 발생되며 교체가 필요하다. 이에 따라 외관 육안조사를 통하여 건전성이 저하된 전주는 매년 교체되고 있다. 외관 육안조사는 Health Index 지표에 의해 이루어지며 건전성과 상관관계가 있다. 본 논문에서는 현장에서 수거된 전주 시험체를 이용하여 정밀시험을 위하여 시험장치를 개발하고 휨 파괴시험에 따른 결과와 Health Index 지표에 의한 결과를 비교하여 콘크리트 전주의 건전성을 평가하였다.