• 한국해양공학회지
• /
• 제22권5호
• /
• pp.94-99
• /
• 2008

Three types of salt resistant concrete beams reinforced with glass fiber reinforced polymer-ribbed bars (GFRP-ribbed bars) were selected, and their applicable properties were investigated with the goal of improving the problem of capacity deterioration in marine structures due to sea water corrosion. In this study, the structural behaviors were similar to RC beams in relation to the development of the strength and stiffness up to the generation of the initial crack. After the growth of this initial crack, the structural properties decreased owing to a sudden loss of bond strength. Also these beams showed the trends of brittle failure. As a result, it was confirmed that a GFS beam replaced with Fly Ash (20%) and Silica Fume (5%) has the best application as a marine structural element.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
• /
• pp.781-786
• /
• 2001

The Salt attack is one of the primary factors that cause the deterioration of durability in steel reinforced concrete structure. And to depreciate the deterioration from the Salt attack in concrete structure, pozzolanic materials are used widely in recent years. In this study, experiments about the resistance of chloride infiltration of concrete according to the replacement rations of Activated Hwangtoh and various pozzolanic materials(silica fume, fly ash, blast furnace slag and non Activated/Activated Hwangtoh) are performed and the results of this study were shown as follows; 1) As the replacement ratios of Activated Hwangtoh were getting higher, the strength of concrete was increased and in case of various pozzolanic materials, strength of Activated Hwangtoh in specimen was better than that of fly ash, blast furnace slag and non Activated Hwangtoh. 2) As the replacement ratios of Activated Hwangtoh were getting higher, the resistance of chloride infiltration of concrete was increased and in case of various pozzolanic materials, silica fume is better than any other pozzolanic materials and Activated Hwangtoh was better than that of fly ash, blast furnace slag and non Activated Hwangtoh.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
• /
• pp.417-418
• /
• 2009

해안 및 매립지 구조물은 염화물의 침투로 인해 매입된 철근의 피막파괴로 철근부식이 일어나 콘크리트 구조체에 열화가 급속하게 진행되기 때문에 앞으로의 해안 구조물의 수밀성, 내염해성을 필요로 한다. 따라서 본 연구에서는 내염해성 개선에 효과적인 액상형태의 Si/Al 복합 무기염을 모르타르에 적용하여 시간경과(7, 14, 28, 56일)에 따른 내염해특성을 파악하고자 하였다.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
• /
• pp.372-375
• /
• 2004

Scaling deterioration and resistance to freezing of port concrete structures due to the combined effects of chemical actions by containning chlorides 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 thaw of concrete by containing chlorides. As a results of this study, it was effective method of scaling deterioration and resistance freewing of concrete, and confirmed the salt deterioration resistance effect to use slag binder against to containing chlorides.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
• /
• pp.782-785
• /
• 2004

Salt attack is one of the serious deterioration factor with respect to the durability of concrete structure. Especially, in case of exposed rebar concrete structure in marine environment, corrosion of rebar is accelerated by penetration of $Cl^-$ from exterior. Through this path, volume of corroded rebar is increased about two and half times due to increased inner pressure originated from rust. As a consequence, the overall deterioration of concrete structure, namely, cracks, reduction of adhesive strength and pop-out is followed. In this paper, the effect of structure treatment of concrete on chloride resistance has been investigated. At the same time, the relationship among several characteristics, such as resistance to chloride, water absorption coefficient and surface hardness of concrete has been investigated. It is believed that surface performance improvement by the application of penetrative hardening agent influences on positively water absorption coefficient, surface hardness of concrete and resistance to chloride ion penetration.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2008년도 추계 학술발표회 제20권2호
• /
• pp.697-700
• /
• 2008

본 연구에서는 고로슬래그 혼합시멘트와 3성분계 저발열 혼합시멘트를 대상으로 하고, 여기에 CSA계 팽창재를 혼입함으로서 이에 따른 수축보상 효과와 함께 염해저항 특성에 미치는 영향에 대하여 검토하였다. 검토결과, 배합조건이 OPC이고, 팽창재 혼입율이 8%인 경우는 팽창재를 혼입하지 않은 경우에 비해 최대 43.7배까지팽창하는 것으로 평가되었고, 굵은골재 최대치수가 콘크리트의 길이변화특성에 미치는 영향은 적은 것으로 나타났다. 염해저항성은 굵은골재 최대치수가 클수록, 그리고 팽창재 혼입율이 증가할수록 개선되는 것으로 평가되었는데, 본 연구범위에서는 팽창재를 8% 혼입한 콘크리트의 염해저항성이 팽창재를 혼입하지 않은 경우에 비해 약 16% 정도 유리한 것으로 평가되었다.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2004년도 학술대회지
• /
• pp.33-38
• /
• 2004

This study was performed to know watertightness and reduction effect and crack occurred by hydration heat, restraint of multiplication of hydration heat, through mechanical test, strength test and crack control test using fluosilicate salt based inorganic compound made from by-product during phosphoric acid manufacturing process. Mix proportions for experiment were modulated at 0.45 of water to cement ratio and $0.5-2.0\%$ of adding ratio of fluosilicate salt based inorganic compound. Evaluation for watertightness of concrete was carried out permeability, absorption test and porosity analysis. Effect of crack reduction was evaluated by length, drying shrinkage as well as stress change of hardened concrete at unrestraint/restraint state and also elucidated crack pattern on the concrete surface. It is ascertained that characteristics of crack resistance and watertightness for concrete was improved by an adequate addition of fluosilicate salt based inorganic compound.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
• /
• pp.467-472
• /
• 2000

It is known that chloride ion in concrete destroys the passive film of reinforcement inside concrete and accelerates corrosion which is the most influencing factor to durability of concrete structures. In this thesis, a chloride ion diffusion model for blast furnace slag(BFS) concrete, which has better resistance to both damage due to salt and chloride ion penetration than ordinary portland cement concrete, is proposed by modifying existing model of normal concrete. Proposed model is verified by comparing diffusion analysis results with both results by indoor chloride penetration test for specimens and field test results for actual RC bridge pier. Also, the optimum resistance condition to chloride penetration is obtained according to degrees of fineness and replacement ratios of BFS concrete. As a result, resistance to chloride ion penetration for BFS concrete is more affected by replacement ratio than degree of fineness.

• 콘크리트학회지
• /
• 제6권6호
• /
• pp.173-179
• /
• 1994

콘크리트내 철근의 부식을 방지하여 내구성을 증대시키기 위해 국내에서 시험 생산한 에폭시도막 철근의 내부식성능을 실험, 평가하였다. 본 연구에서는 국내 산업규격(KS)과 미국재료시험기준 시험결과로부터 에폭시도막 철근을 내약품성능, 염화물 투과성은 양호하였다. 그러나, 에폭시도막 철근표면의 결함부에서 부식이 발생되었으며 도막두계 $200{\mu}m$ 미만의 시험체에서 부식발생률이 높았다. 4mm 정도의 부분에폭시 도막손상은 전체적인 부식에 영향을 미치지는 않았다. 도막의 결함이 생기지 않도록 에폭시도막 과정에서 철근의 표면처리에 주의가 특별히 필요하다.

• 한국건축시공학회지
• /
• 제22권5호
• /
• pp.425-430
• /
• 2022

초고층 건축물용 매트기초에 사용되는 콘크리트는 시공성 및 품질확보를 위하여 일체타설로 진행되는 경우가 많다. 하지만 일체타설의 경우 수화반응 과정에서 온도균열이 발행할 우려가 높으며 혼화재 치환을 통해 고성능 고내구성 콘크리트 최적배합을 도출할 필요가 있다. 본 연구에서는 저자의 기존연구에서 도출한 최적 고성능 저발열 콘크리트 배합으로 제작된 시험체를 대상으로 염해 및 탄산화, 내황산염에 대한 실험을 실시하고 염소이온 확산계수와 탄산화계수, 황산염에 대한 시멘트 매트릭스의 저항을 정량적으로 평가하였다. 혼화재의 혼입에 의한 잠재수경성 및 포졸란 반응에 의한 높은 저항성을 확인할 수 있었다.