• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 추계 학술논문 발표대회
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• pp.46-47
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• 2018

High performance concrete with low water-to-cement ratio has been widely used with increased demand of high rising buildings and huge scaled structures. Additionally, for high performance concrete, various SCMs are replaced to improve its performance from fresh state to hardened state. With the drawback of increased viscosity of the concrete mixture for high performance concrete, low-viscosity typed high range water reducer is the relatively new admixture. Therefore, as a goal of the research, under using various SCMs with wide range of content, the performance of low-viscosity typed high range water reducer was evaluated. Especially, in this research, the influence of low-viscosity typed high range water reducer on rheological properties including plastic viscosity and yield stress were assessed. As a result of the research, it is expected to provide a fundamental information of low -viscosity typed high ranged water reducer on high performance concrete with various conditions of SCMs.

• 한국건축시공학회지
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• 제13권6호
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• pp.594-601
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• 2013

One of the important problems associated with building demolition is the dust generated during the work. The only way to reduce the demolition dust is to use a dust net during water spraying. However, it is difficult to supply the necessary amount of water to remove demolition dust, thus making it difficult to apply this method on a demolition site. This work attempted to find an alternative approach to dust removal by incorporating surfactant and high range AE water reducer in the water being sprayed. Through the experiment, it was found that the addition of surfactant did not contribute to the removal of demolition dust. However, the use of high range AE water reducer showed better performance than spraying plain water, indicating that some amount of demolition dust had been adsorbed on the high range AE water reducer.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2015년도 추계 학술논문 발표대회
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• pp.115-116
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• 2015

Since concrete has evolved to the development of the quality and performance there currently being used civil engineering, as the most important material in the construction sector. But the discovery of alternative building materials and indiscriminate use is negligible. So that is the situation facing the shortage of natural aggregate. Accordingly, this study reviewed the mechanical properties by replacing the aggregate through the mud flat of eco-friendly materials and analyze the usability by adding a high-performance water reducer for promoting workability.

• 콘크리트학회지
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• 제7권3호
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• pp.156-163
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• 1995

앞 선 연구에서는 스티렌과 무수말레인산으로부터 스티렌-무수말레인산 공중합체(SMA)를 합성하고 이들을 황산화하여 수용성의 SMA를 제조하였다. 본 연구에서는 이들 카르본산계 공중합체를 첨가한 시멘트 모르타르의 플로우 및 경화시멘트 모르타르의 강도를 조사하여 고성능감수제로서의 성능을 평가하였다. 플로우 실험 결과 황산화 SMA(SSMA)를 첨가한 시멘트 모르타르의 플로우는 아미노페놀이 치환된 황산화 SMA(SmSMA)를 첨가한 경우보다 더 큰 값을 나타내었다. 또한 공중합체를 첨가한 시멘트 모르타르의 플로우 유지율은 기존의 나프탈렌계(NSC)를 첨가한 경우보다 우수하게 나타났다. 시멘트 모르타르에 SMA와 SmSMA를 시멘트 중량에 대해 0.5% 첨가하여 제조한 경화 시멘트 모르타르의 28일 압축강도를 조사하였다. 그 결과 SSMA 및 SmSMA를 첨가한 경우 plain 보다 각각 31%와 13%의 강도 증가를 나타내었다. 이상의 결과로부터, 본 연구에서 사용한 SSMA 및 SmSMA의 카르본산계 공중합체는콘크리트용 고성능감수제로서 크게 기대되어진다.

• 콘크리트학회지
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• 제15권5호
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• pp.39-44
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• 2003

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1995년도 봄 학술발표회 논문집
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• pp.142-147
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• 1995

In this study, styrene-maleic anhydride copolymer (SMA) was synthesized from styrene and maleic anhydride and further reacted with sulfuric acid to obtain water-soluble SMA and the flow and strength tests of cement mortar mixed with copolymers were carried out to evaluate the capability of copolymers as high range water reducer for the concrete. It was found from flow experiment that the fluidity of cement mortar mixed with sulfonated SMA (SSMA) was larger than that miced with aminophenol-substituted SSMA (SmSMA). The decreasing rate of the flow of cement mortar mixed with SSMA and SmSMA was decreasing rate of the flow of cement mortar mixed with SSMA and SmSMA was significantly lower than that mixed with naphthalene condensate (NSC). The compressive strength of the hardened cement mortars containing 0.5% copolymers after 28 days curing was examined. The compressive strength of hardened cement mortar containing SSMA and SmSMA was increased up to 32% and 13%, respectively, when compared to the plain. As the results, the copolymers (SSMA and SmSMA) used in this study are greatly expected as a good high range water reducers for the concrete.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 추계 학술논문 발표대회
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• pp.32-33
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• 2017

In order to improve the flow performance of high performance concrete, use of high performance water reducing agent and low viscosity type water reducing agent is a study of suitable range of use due to side effects. in this study, we aimed at reducing viscosity and yield value using high performance water reducing agent and low viscosity type water reducing agent, and this was evaluated using a rheometer. as a result of analysis of viscosity and yield value, it was found that the high performance water reducing agent has higher reduction effect than the low viscosity type water reducing agent. however, the larger the viscosity lowering effect is, the lower the usable range is, compared to general high performance water reducing agents, and it was found that sufficient consideration for this judgment of appropriate quantity is necessary.

• 콘크리트학회지
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• 제7권2호
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• pp.175-182
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• 1995

스티렌과 무수말레인산의 라디칼 공중합에 의해 스티렌-무수말레인산 공중합체(SMA)를 합성하고 SMA를 m-amino phenol과 치환반응하여 m-amino phenol 이 치환된 스티렌-무수말레인산 공중합체(mSMA)도 합성하였다. 합성한 SMA와 mSMA를 황산화하여 각각 황산화 SMA(SSMA) 및 황산화 mSMA(SmSMA)를 제조하였다. 공중합체의 합성은 적외분광스펙트럼의 특성피크로부터 확인할 수 있었다. 원소분석 결과 mSMA의 m-amino phenol의 치환율은 44%이었고 이것은 황산화 과정을 거치면서 35%로 감소하였다. 공중합체의 시멘트에 대한 흡착실험 결과 공중합체의 첨가량이 적을수록 흡착율이 높게 나타났고, 첨가량에 관계없이 SSMA의 흡착율이 SmSMA의 그것보다 크게 나타났다. 본 연구에서 합성한 공중합체 (SSMA, SmSMA)는 시멘트 분산제로서의 가능성이 기대되어진다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1994년도 봄 학술발표회 논문집
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• pp.260-265
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• 1994

High strength concrete(65MPa) was used for construction of the bulk cement storage silo by using sliding form. This paper presents mix design, production, quality control and experience with field application of high strength concrete under cold weather conditions. It is shown to be possible to produce high strength concrete of compressive strength of 50~60 MPa by using high-range water reducer to lower w/c ratio with appropriate quality control.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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• pp.442-445
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• 2004

The mock-up test was carried out to solve several problems of the hot weathered high strength concrete. The workability of concrete could be guaranteed by using high range water reducer containing polycarboxylic acid. The compressive strength calculation by rebound value of Schumidt hammer underestimated the actual strength of concrete structure. The temperature of concrete should be lowered by control of raw material temperature and transportation.