• Computational Structural Engineering
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• v.24 no.1
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• pp.26-30
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• 2011

• Proceedings of the KSR Conference
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• 2006.05b
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• pp.630-635
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• 2006

• Magazine of the Korean Society of Agricultural Engineers
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• v.28 no.2
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• pp.74-86
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• 1986

유동화콘크리트의 공학적 특성에서 시간-의존거동을 확인하기 위하여,나프타렌 설폰산염 폴리머 고축합물인 Rheobuild 1000과 메라민 설폰산염 고축합물인 NP-20의 고성능감수제를 사용한 유동화콘크리트와 보통콘크리트를 제조하여 비교.고찰을 행하였으며, 고성능감수제의 종류 및 함량이 콘크리트의 공학적 특성에 미치는 영향을 구명하기 위하여 재령 3일, 14일, 28일, 60일, 90일, 180일의 압축강도를 측정, 조기 및 장기압축강도를 조사하였고, 인장강도 및 탄성 변형에 미치는 영향을 조사하였다. 또한 습윤 및 에어콘디션의 양생조건하에서 시간의 경과에 따른 건조수축 및 크리이프 변형을 조사.분석함으로써 유동화콘크리트의 시간-의존거동을 확인하였다. 실험결과, 사용 고성능 감수제의 종류에 따라 차이는 있으나, 고성능 감수제의 사용은 일반적으로 워커빌리티 성능을 개선하고 압축 및 인장도를 크게 향상시키며, 탄성계수는 보통의 콘크리트에 비하여 높게 나타났다. 또한 건조수축 및 크리프 변형의 감소에 매우 양호한 결과를 나타내어 앞으로 건설용 용도로써 효과적인 것으로 판단되었다.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.3
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• pp.235-242
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• 2019

The objective of this study is to modify the mixture proportions of concrete that were developed for section enlargement strengthening elements using a specially designed binder composed of 5% ultra-rapid hardening cement, 10% polymer, and 85% ordinary portland cement in order to assign the self-compaction property to such concrete. The self-compaction abilities of concrete were estimated by the performance criteria specified in JSCE and EFNARC provions. Test results showed that the increase in the unit binder content at the consistent water-to-bider ratio led to increase in viscosity of fresh concrete but did not exhibit the decrease in the fluidity due to a greater viscosity. The mixture proportioning of self-compaction section enlargement concrete could be considered at the following conditions: unit binder contents of $430kg/m^3{\sim}470kg/m^3$ and fine aggregate-to-total aggregate ratios of 40%~46% at the water-to-binder ratio of 38%.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.216-216
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• 2020

최근 하천에서는 다양한 하천복원기술이 개발·적용되고 있으나, 하천관리의 패러다임 변화로 하천에서의 환경복원이 커다란 이슈가 되고 있다. 과거 치수 위주로 추진되어온 결과, 하천에서는 콘크리트 활용 기술이 과다하게 유입됨으로 인하여 치수에는 안전하나 하천 경관 훼손 및 하천생태계에 악영향을 미치고 있다. 특히 콘크리트를 활용한 기술은 높은 안정성을 바탕으로 세굴방지에 좋은 장점을 지니고 있으나, 하천에 적용 시 하천생물에 악영향을 미치는 강알카리(pH 12정도)를 지속적(10년)으로 용출하여 하천생태계에 악영향을 미치고 있다. 또한 하천에 대한 심미성에 영향을 미치게 되어 하천경관에 나쁜 영향을 미치고 있다. 본 연구에서는 이러한 독성물질이 포함된 콘크리트 대신 Biopolymer 접착소재와 같은 무독성 소재를 활용하여 다층다공성 하상보호공을 개발하였으며, 과학적인 검증을 통하여 안정성을 확인하였다. 이를 현장에 적용성을 확인하기 위하여 김해시 대청천 대청1보에 시범사업을 하였으며, 개발된 기술에 대한 안전성 및 생태성을 검증을 위하여 2015년부터 2018년까지 물리적/화학적/생물학적 모니터링을 수행하였다.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.469-470
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• 2009

Recently, so that HSC can secure the fire resistance properties at the time of a fire in super tall building suggested method of combined fiber. Thus, there is the purpose to develop the high fireproof concrete which applied method of combined fiber which can satisfy flowability and the fire resistance properties of HSC for construction of the super tall building.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.395-396
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• 2010

The purpose of this research is that development of fire-high resistance concrete for high-rise buildings is carried out with a test, which is for confirmation of fire-resistance capacity of 80MPa high-strength concrete. In this test, self-developed Polymix to confirm fire-resistance capacity of high-strength concrete in domestic high-rise buildings recently is applied.

• Journal of the Korea Institute of Building Construction
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• v.8 no.6
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• pp.131-137
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• 2008

In recent years, the light-weight aggregate has widely been used to reduce the weight of construction structures, and to achieve the thermal insulation of building structures. The purpose of this study is to evaluate the heat resistance of polymer concrete composites with light-weight aggregate made by binders as resin and cement with polymer dispersion. The light-weight polymer concrete composites are prepared with various conditions such as binder content, filler content, void-filling ratio, light-weight aggregate content and polymer-cement ratio, and tested for heat resistant test, and measured the weight reducing ratio, strengths and exhaustion content of gas such as CO, NO and $SO_2$. From the test results, the weight reducing ratio of light weight polymer concrete using UP binder after heat resistance test increase with an increase in the UP content irrespective of the filler content. The weight reducing ratio of polymer cement concrete is considerably smaller than that of UP concrete. In general, the strengths after heat resistance of polymer concrete composites are reduced about 40 to 65% compared with those before test. The exhausted quantity of CO, NO and $SO_2$ gases in polymer concrete composites is less than EPS(Expanded poly styrene). From the this study, it is confirmed that the many types gases discharge according to binder type of polymer concrete composites, its amount is controlled by selection of the binder type and mix proportions.

• Magazine of the Korea Concrete Institute
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• v.5 no.4
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• pp.145-155
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• 1993

The results of an experimental study on the manufacture and the mechanical properties of fiber reinforced fly ash$\cdot$lime$\cdot$gypsum composites are presented in this paper. 'The composites using fly ash, lime, and gypsum were prepared with various fibers (PAN-derived and Pitch-derived carbon fiber, alkali-resistance glass fiber) and a small amount of polymer emulsion-styrene butadiene rubber latex (SBR). As the test results show, the manufacturing process technology of fly ash$\cdot$lime$\cdot$gypsum composites was developed and its optimum mix proportions were successfully proposed. And the flexural strength and toughness of fiber reinforced fly ash$\cdot$lime $\cdot$gypsum composites were increased remarkably by fiber contents, but the compressive strength of the composites were influenced by the kinds fiber more than by the fiber contents. Also, the addition of a polymer emulsion to the composites decreased the bulk specific gravity, but the compressive and flexural strength, and the toughness of the composites were not influenced by it, but were considerably improved by increasing fiber contents.

• Magazine of the Korea Concrete Institute
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• v.4 no.1
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• pp.107-118
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• 1992

In order to examine the mechanical properties of carbon fiber reinforced cement composites with silica powder PAN - based carbon fiber and Pitch- based carbon fiber, and polymer impregnators experimental studies on CFRC impregnated in polymer were carried out. The effects of types, length, and content~i of carbon fibers and matrices of fresh and hardened CFRC impregnated in polymer were examined. The test results show that compressive, tensile, and flexural strength of CFRC impregnated in polymer were much more iriCreased than those of air cured and autodaved CFIIC CFRC impregnated in polymer was also considerably effective in improving toughness, freeze thaw resistance, loss of shrinkage, and creep resist ance, compared with air cured and autoclaved CFRC.