• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표회 논문집(I)
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• pp.191-196
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• 1998

Under concentrational paste and dilute suspension systems, we have been tested the effects in the dosage of two superplasticizers [naphtalenic(NSF) and polycarboxylic(NT-2)] which has been varied from 0 to 2.0 wt%, in both one case of cement Ⅱ-anhydrite and fly ash itself and the other case that cement has been substituted 10wt% to Ⅱ-anhydrite and fly ash. The result of tested zeta potential tells that zeta potential values increase in addition to increasing of the NSF dosage. And it's effect was high in case of fly ash. We has confirmed the 10wt% substitution of Ⅱ -anhydrite and fly ash would be more effective than the cement itself in initial fluidity and stable fluidity. And in case of NT-2 and NSF, addition of 1.0wt% NT-2 improved the fluidity of paste cement more than that for NSF.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1989년도 가을 학술발표회 논문집
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• pp.35-38
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• 1989

The purpose of this report is to investigate and analyze development and achievement of flowing and high-strength concrete by reacy mixed concrete companies in Korea. For this purpose, the investigation was divided into three parts, i.e., superplasticizers, flowing concrete, high-strength concrete. And, they were asked to quality control manager in ready mixed concrete companies. Many researches have been carried out. And, flowing concrete is applied to field in a few case. In order to improve practical applicability of high-strength concrete and make concrete strength higher, to begin with, profound research for concrete ingredients will be needed along with presentation of methods for obtaining workability and quality assurance.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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• pp.539-544
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• 2002

The properties of mortar and concrete including metakaolin as a partial cement replacement were investigated in terms of fluidity and compressive strength. The results show that mortar and concrete in which 10 % of cement is replaced with metakaolin exhibit much higher compressive strength after 3 days of hydration than ordinary Portland cement, indicating that metakaolin can be used in the production of high strength concrete replacing silica fume. The type of superplasticizer largely affected on the fluidity and compressive strength of mortar and concrete including metakaolin. It was concluded that when metakaolin is used for the purpose of manufacturing high strength concrete, it is desirable to use PNS based blends rather than PNS, PMS and polycarboxylate based superplasticizer.

• 콘크리트학회지
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• 제5권2호
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• pp.121-128
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• 1993

나프탈렌 또는 나프톨을 황산화하고 포름알데히드와 축합 반응시켜 나프탈렌 축합물 및 나프톨 축합물을 합성하였다. 또한, 나프탈렌과 나프톨을 모두 함유하는 공축합물도 합성하였다. 이들 축합물의 확인은 핵자기공명스텍트럼, 적외분광스펙트럼, 자외분광스펙트럼으로 행하였다. 한편 이들 축합물들의 시멘트에 대한 분산성을 예측하기 위하여 시멘트 표면에의 흡착실험을 행하였다. 그 결과 수산기를 함유하는 나프톨 축합물(TSC)>나프탈렌-나프톨공축합물(NSS)의 순으로 시멘트에 대한 흡착율이 증가했다. 위의 결과들로부터 주쇄(main chain)에 나프톨을 함유하는 합성축합물(TCS, NT5)은 시멘트분산제로서의 가능성이 시사되었다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.415-418
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• 2005

Nowadays the three major commercially available of organic chemical admixtures are modified lignosulfonates(LS), sulfonated naphthalene-formaldehyde resins (SNF) and sulfonated melamine-formaldehye (SMF). In this study, various sulfonated melamine-formaldehyde (SMF) superplasticizers were synthesized via four synthetic steps. Hydroxymethylation (Step 1), Sulfonation (Step 2), Polymerization (Step 3) and Neutralization and Stabilization (Step 4). In this synthesis of SMF, reaction conditions such as the mole ratio of melamine to formaldehyde and the amount of acid catalyst were changed. After application of SMF superplasticizer to cement paste and mortar, the physical properties including workability, slump loss, compressive strength were compared.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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• pp.77-80
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• 2006

Graft copolymerized polycarboxylate(PC)-type superplasticizers(PCs) which have carboxylic acid with $\pi$ bond among the molecular structure and polyethyleneglycol methyl ether methacrylate(PMEM) were synthesized by free radical reaction and investigated the chemical structure, polymerization condition, and physical and chemical properties. Also, the effects of PCs in the dispersion, adsorption and hydration of cement were evaluated. As the molecular weight of graft chain decreases, the adsorption amount on cement particles increased. It was advantageous for the flow to reduce molar ratio, the lower the side bone molecular weight, and increase the molar ratio, the larger the side bone molecular weight. The hydration reaction speed was highly delayed at day 1, due to increase in molar ratio and reduction in side bone molecular weight, but it was recovered in the days after.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 추계 학술발표회 제20권2호
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• pp.729-732
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• 2008

나프탈렌계 유동화제는 오랫동안 콘크리트 혼화제중 AE감수제의 주요성분으로 우수한 효과 때문에 널리 사용되어 왔으나 포름알데히드의 혼용으로 인해 유해성이 지적되어 왔다.따라서 본 연구에서는 AE 감수제에 사용되는 나프탈렌계 고성능감수제(PNS)에서 합성과정에서 포르말린을 적용하지 않은 PNS 치환용 혼화제를 제조하고, 이를 콘크리트에 적용하여 PNS를 사용한 기존 AE감수제와 콘크리트의 기초물성에 미치는 효과 및 친환경 특성을 평가하였다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.671-674
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• 2005

In this study, it is examined the properties of early strength of concrete mixed with polycarboxylate superplasticizer. For this experiment, it is analyzed that the slump and strength properties according to the mixture factors, compared with cements and superplasticizers of each company and curing temperature($15,\;20^{\circ}C$). (1) The slump loss of concrete used polycarboxylate superplasticizer(rapid strength type) showed $0.5\~1.5cm$, it is judged that slump loss according to the time lapse can be minimized. (2) The performance of polycarboxylate superplasticizer kept up consistency and accelerated strength development. it is possible to reveal 12MPa within $18\~20$hours at $20^{\circ}C$ curing, but impossible within 24hours at $15^{\circ}C$. (3) It is necessary to studies about rapid strength development in the low temperature.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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• pp.457-460
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• 2008

최근의 콘크리트 기술은 시멘트 제조기술의 발전 보다는 화학 혼화제의 기술발전에 의하여 성장하였다. 현재, 콘크리트 산업에 주로 사용되고 있는 4가지 화학 혼화제로서 변형된 리그닌(LS), 나프탈렌계(SNF), 멜라민계(SMF) 및 폴리카르복실레이트계(PC)계가 있다. 본 연구에서는 SMF계 고유동화제를 멜라민과 포르말린의 몰비를 변화 시키며 4단계로 나누어 반응을 진행시켰다. 합성된 SMF계 고유동화제를 시멘트 콘크리트에 적용하여 작업성, 슬럼프 손실 및 압축강도를 SNF와 비교하였다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.801-804
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• 2006

Polycarboxylate type superplasticizers(PC) have got widely used for making not only high performance concrete but low grade concrete as well. It is known that fluidity of cement with PC is affected by the characteristics of cement especially sulphate ion concentration and hydration activity. But the characteristics of PC also affect the fluidity. The fluidity of cement mortar with various types of PC was measured and critical dosage(CD) and dispersing ability(DA) was calculated. CD and DA is strongly dependent on the type of PC. And the variation of fluidity on time was affected by the type of PC also. So, it is advisable to investigate the property of PC before production of concrete and adjust it to meet the requirements of concrete depending on the materials, the time of transport and so on.