• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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• pp.415-416
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• 2009

Concrete with Self-healing Admixture provides waterproof protection by using a organic-inorganic chemical compound throughout the concrete. Using cement chemicals eliminate the need to use additional waterproofing, If crack is occurred, this system enhance self-healing ability to increase the structural safety. In this study, we investigate material properties to conclude mixture rate of concrete to apply a construction site.

• Journal of Plant Biotechnology
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• 제36권3호
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• pp.261-267
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• 2009

The coexistence policy of GM and non-GM crops is still on the debates in EU since “the recommendation on guidelines for the development of national strategies and best practices to ensure the coexistence of GM crops with conventional and organic farming” has been reported in 2003. The major issues are maximum tolerance level of GMO admixture and minimum isolation distances of GM fields with others including conventional, organic and seeds production. Majority of member states in EU proposed that the tolerance level of GMO admixture must be more strictly controlled, in particular in the fields for organic crops and seeds production. To this end, it was proposed that minimum isolation distances to segregate GM crops from fields with organic crops and seeds production need to be further extended than those of conventional crops since cross pollination with other crops adjacent GM fields is known as the most prevalent source for GMO contamination. In these circumstances, it is strongly suggested that the current legislations need to be revised including the minimum isolation distances of fields for each species before field cultivation for a commercial GM crop is approved for the first time in South Korea.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회 논문집(II)
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• pp.967-974
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• 2000

By testing compressive strength, water absorption and water premeablity, to establish the standard of quality of waterproofing admixture of power type for concrete, we propose guide line as following ; $.$Setting time: more than 1 hour, within 10 hours $.$Slump: To be satisfied with request of user $.$Air content: To be satisfied with request of user $.$Safety: Without crack or deformation $.$Ratio of compressive strength: $\circled1$ At 3 days : more than plain specimen by 0.9 (An inorganic material) more than plain specimen by 0.4 (An inorganic material mixed organic) $\circled2$ At 7, 28 days : more than plain specimen by 1.0 $.$Ratio of water absorption Coefficient: $\circled1$An inorganic material: less than plain specimen by 1.0 $\circled2$ An inorganic material mixed organic : under than plain specimen by 0.8 $.$Ratio of water premeablity : $\circled1$ An inorganic material : less than plain specimen by 1.0 $\circled2$ An inorganic material mixed organic : under than plain specimen by 0.8

• 대한토목학회논문집
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• 제8권2호
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• pp.117-124
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• 1988

국산 플라이애쉬 6종류에 대한 AE제의 흡착특성(吸着特性)을 살펴 본 결과 플라이애쉬 입자의 AE제흡착(吸着)은 30분 정도에서 거의 완료되었으며 강열감량이 클수록 포화흡착량이 크게 나타났다. 플라이애쉬 강열감량의 대부분은 미연소탄소(未燃燒炭素)이며 따라서 미연소탄소량이 AE콘크리트 중의 공기량을 감소시키는 요인임을 알았다. 한편, 유동화제(流動化劑)의 경우 플라이애쉬 입자의 포화흡착량은 시멘트보다 적으며 시멘트의 경우보다 분산성(分散性)도 다소 낮으나 플라이애쉬를 혼합한 콘크리트에 유동화제를 사용할 경우 유동성이 저하되는 현상은 없었다.

• KCI Concrete Journal
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• 제13권1호
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• pp.3-9
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• 2001

This research concerns the effect of kaolin as material of cement admixture. which has the advantage of low price and high adaptability. Kaolin, a kind of soil, is well known as a raw material of pottery. which is widely scat-tered on the earth (especially in Korea). This research shows the method and process for activating kaolin to have the properties of a cement admixture through experiment. In the experiments, kaolin is baked in high temperature and then cooled suddenly to be activated. The temperature zone and time span, on which kaolin is activated are examined. The research looks over the effect of the activated kaolin based on several criteria regarding to chemical and physical characteristic of general admixtures. The results of this research are as follows; kaolin start activation at the temperature above 50$0^{\circ}C$ and make ends of activation at the temperature below 95$0^{\circ}C$ and there was little effect by the change of duration. It is concluded that compressive strength can be increased by putting activated kaolin in the concrete and the activated kaolin is good for water resistance and anti-chemical , and that it is effective for protecting the leakage of hazardous article like Cl- and for protecting damage by an organic salt like acid. The activated kaolin of proper temperature and time is effective in compressive strength, salt resistance and acid resistance. The adaptability of activated kaolin as a cement admixture was shown through this research.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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• pp.441-442
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• 2009

Concrete has some self-healing ability if the crack is occurred. Concrete with a inorganic-organic chemical compound, self-healing ability is increased at the surface of the crack. In this study, we investigate self-healing performance of concrete using admixutre by performing permeability test.

• 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.

• 한국세라믹학회지
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• 제21권2호
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• pp.143-148
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• 1984

In this study we mainly dealt with the effects of organic retarder(calcium lignosulfate) on the early hydration process of clinker minerals. From a consideration of the hydration process of tricalcium silicate $(C_3S)$ tricalcium silicate $(C_3S)$-tricalcium aluminate $(C_3A)$ tricalcium silicate $(C_3S)$-tetracalcium aluminof-errite $(C_4AF)$ systems with calcium lignosulfate the following results were obtained. 1. when 0.25wt% of CLS was added to $C_3S$ the hydration process was progressed normally but adding of 0.5wt% its hydration was greatly retarded. 2. The hydration of $C_3S$-$C_3A$ system was progressed normally up to 0.5wt% but by adding gypsum its hydration was retarded slightly. 3. The hydration of $C_3S$-$C_4AF$ system was greatly retarded even with 0.25wt% of CLS but by adding gypsum its hydration process was recovered normally.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2009년도 춘계 학술논문 발표대회 산업계
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• pp.99-102
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• 2009

This paper is to present the performance data for pressure setting method using some tile bonds for application on the Ondol-Heating floor system. For this purpose, powder and liquid tile bonds(Organic.Inorganic mixed tile bonds) were compared with the conventional tile cement for pressure setting method in the sight of the adhesive stability of porcelain tile. It tested for tiles after 14, 28days under standard condition and severe conditions. The severe conditions were water immersion and heat ageing($70^{\circ}C$). Another experimental factors concerned tile bond properties such as mixing ratio(in case of using liquid admixture), open time, which are supposed to affect the tensile strength of tile, were studied and discussed through the experiments.

• 한국세라믹학회지
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• 제52권6호
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• pp.479-482
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• 2015

The flue gas desulfurization (FGD) process is one of the most effective methods to reduce the amount of $SO_2$ gas (up to 90%) generated by the use of fossil fuel. Limestone is usually used as a desulfurizing agent in the wet-type FGD process; however, the limestone reserves of domestic mines have become exhausted. In this study, limestone sludge produced from the steel works process is used as a desulfurizing agent. Seven different types of additives are also used to improve the efficiency of the desulfurization process. As a result, alkaline additive is identified as the least effective additive, while certain types of organic acids show higher efficiency. It is also observed that the amount of FGD gypsum, which is a by-product of the FGD process, increases with the used of some of those additives.