• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 가을 학술논문 발표대회
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• pp.115-116
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• 2022

Large concrete mass members are commonly used as matte bases for skyscrapers. In general, Integral casting is preferred to secure construction convenience and durability quality rather than separate casting. However, there is a possibility that cracks may occur in the early stages due to the generation of a lot of hydration heat, and thus durability will decrease, so it is necessary to determine an appropriate mixture and verify it through experiments. The purpose of the study was to conduct a review on the durability of the optimal high-performance low-heating concrete combination derived through the experiment and to conduct a review analysis on the performance satisfaction and performance expression mechanism.

• 한국구조물진단유지관리공학회 논문집
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• 제20권3호
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• pp.140-148
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• 2016

이 논문은 표면 차수벽형 석괴댐(Concrete-Faced Rock-Filled Dam) 콘크리트의 내구성능 개선에 관한 것이다. 댐은 영구 구조물이며 그 중요성을 감안할 때 충분한 내구성능이 확보되어야 한다. 이 논문에서는 플라이애시와 PVA 섬유를 혼입함으로써 차수벽 콘크리트의 내구성능을 개선하고자 하였으며, 플라이애시와 PVA 섬유 혼입율에 따른 내구성능 향상 검증을 위하여 기본물성 (강도, 소성수축, 자기수축)을 포함한 내구성능 검증 실험(염소이온 침투, 마모 저항성, 동결융해 저항성)을 수행하였다. 실험 결과, 플라이애시 15%와 PVA 섬유 0.1%를 혼입하였을 때 내구성능 개선 효과가 뛰어난 것으로 나타났다. 검증된 차수벽 콘크리트의 현장 적용을 통해 표면 차수벽형 석괴댐의 안전성 및 내구성 개선에 기여할 수 있을 것으로 판단된다.

• Computers and Concrete
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• 제19권4호
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• pp.357-363
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• 2017

This paper conveys the effects of fly ash and silica fume incorporated in concrete at various replacement ratios on the durability properties of concretes. It is quite well known that concrete durability is as much important as strength and permeability is the key to durability. Permeability is closely associated with the voids system of concrete. Concrete, with less and disconnected voids, is assumed to be impermeable. The void system in concrete is straightly related to the mix proportions, placing, compaction, and curing procedures of concrete. Reinforced concrete structures, particularly those of subjected to water, are at the risk of various harmful agents such as chlorides and sulfate since the ingress of such agents through concrete becomes easy and accelerates as the permeability of concrete increases. Eventually, both strength and durability of concrete reduce as the time moves on, in turn; the service life of the concrete structures shortens. Mineral additives have been proven to be very effective in reducing permeability. The tests performed to accomplish the aim of the study are the rapid chloride permeability test, pressurized water depth test, capillarity test and compressive strength test. The results derived from these tests indicated that the durability properties of concretes incorporated fly ash and silica fume have improved substantially compared to that of without mineral additives regardless of the binder content used. Overall, the improvement becomes more evident as the replacement ratio of fly ash and silica fume have increased. With regard to permeability, silica fume is found to be superior to fly ash. Moreover, at least a 30% fly ash replacement and/or a replacement ratio of 5% to 10% silica fume have been found to be highly beneficial as far as sustainability is concerned, particularly for concretes subjected to chloride bearing environments.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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• pp.173-176
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• 2006

Concrete has been considered as a semi-permanent structural material, because its excellent durability. But concrete durability is affected by carbon dioxide, chloride, water, etc. This study is about surface protection materials-one materials is silane type and the other silicate type for the promoting of concrete durability. As a results, Silane type could protect affection of chloride(Cl-), water(H2O), carbon dioxide(CO2). Also silicate type could improve the abrasion of concrete.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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• pp.419-424
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• 2000

The primary objectives of this study are to investigate the properties of strength and durability of recycled aggregate concrete was added polypropylene as variables and to fabricate fine concrete in some conditions. The variables are substitution ratios of recycled aggregate(0, 30, 50, 100%) and additions of polypropylene(0, 0.2, 0.5, 1.0%). Compressive strength test to investigate strength properties and freeze-thawing test and drying shrinkage test to durability properties were done. As the result of this study, When variables are substitution ratio(30%) of recycled aggregated and addition(0.5%) of polypropylene, fine concrete was fabricated.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 봄 학술발표회 논문집(I)
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• pp.293-298
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• 1998

The result of an experimental study on the mechanical properties and durability of polypropylene fiber reinforced concrete are presented in this paper. This study has been performed to obtain the properties of PFRC such as strength, toughness and durability. The test variables are fiber content, fiber types, W/C ratio. PFRC shows the highest strength when the polypropylene fiber contents were increased to 2.0 vol.%. Also, freeze-thaw resistance and carbonation were somewhat more improved than plain concrete.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1995년도 가을 학술발표회 논문집
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• pp.80-83
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• 1995

In order to develope and apply high-performance steel fiber reinforced concrete (SFRC), the effects of steel fibers on durability and long-term deformation of SFRC due to various mixing conditions have been studied. As the test result show, the manufacturing process technology of industrial SFRC is developed And the durability of SFRC such as freeze-thaw, resisteance abrasion resistance are significantly improved, the drying shrinkage of SFRC, is remarkably decreased by increasing the steel fiber contents than plain concrete

• Advances in concrete construction
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• 제4권2호
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• pp.107-121
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• 2016

This concrete is one of the most versatile construction material widely used for almost a century now. It was considered to be very durable material and required a little or no maintenance since long time. The assumption is very true, except when it is subjected to highly aggressive environments. The deterioration of concrete structures day by day due to aggressive environment is compelling engineers to assess the loss in advance so that proper preventive measure can be taken to achieve required durability to concrete structures. The compounds present in cement concrete are attacked by many salt solutions and acids. These chemicals are encountered by almost all concrete structures. The present study has been undertaken to investigate the effect of attack of chlorides and sulphates with varying severity on compressive strength of ground granulated blast furnace slag (GGBFS) concrete after immersion in salt solution for 28 days. The results indicate that the durability of GGBFS concrete increases with the increase in percentage replacement of cement by GGBFS for 20% and then gradually decreases with increases in percentage of GGBFS with cement (as in the study for 40% and 60%). Also there is increase in strength of GGBFS concrete with increase in age. Thus the durability of concrete improves when GGBFS is added as partial replacement of cement. In this study the strength of GGBFS concrete is less affected by chemicals as compared to conventional concrete when exposed to aggressive environment.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2005년도 추계 학술논문 발표대회
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• pp.93-96
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• 2005

Concrete has been considered as a semi-permanent structural material, because its excellent durability. Recently, durability decline of concrete construction by environmental pollution is becoming social problem. The durability of high durable structure is declined by carbonate, chloride permeation and deterioration of waterproof performance, etc. This study of penetrating surface protection materials evaluated about carbonation, chloride permeation, waterproof performance, and durability of abrasion, etc. It is profitable in durability that spread penetrating surface protection materials

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.821-826
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• 2000

Reinforced concrete is in general known as high durability construction material under normal environments due to strong alkalinity of cement. Marine concrete specimens in the tidal and the splash zone at seashore have been exposed to cyclic wet and dry saltwaters which cause to accelerate corrosion of reinforcing steel in concrete. If corrosion resistance of concrete gets to weaken de to carbonations and cracks in cover concrete, furthermore, concrete durability rapidly decreases by the corrosion of reinforcement steel embeded in concrete. The objective of this study is to develop appropriate corrosion protection systems of marine concrete so as to enhance the durability of concrete by establishing pertinent cover depth of concrete and by using corrosion inhibitors as concrete admixtures.