• 한국염색가공학회지
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• 제26권1호
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• pp.32-38
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• 2014

There has been increasing demand to the eco-friendly materials such as phytoncide which is extracted to plants in the textile industry, recently. It is interesting that alginic acid sodium salt(Alg-Na) is used to eco-friendly binder for the functional capsule finishing. In this study, we made PEO/Alg-Na blend solutions of various ratio and observed the changing binding property of the blend solutions according to PEO contents through FT-IR, DSC, contact angle, peel strength, etc. The viscosity of Alg-Na/PEO blend solutions increased with increase of contents and the viscosity quickly increased with increase of PEO content in Alg-Na 5% content, specially. It is shown that the hydrogen bond peak by blend of Alg-Na and PEO found through FT-IR analysis but the peak decreased in PEO above 60% content. And the peel strength was predominant in PEO 50% ratio.

• Elastomers and Composites
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• 제29권5호
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• pp.431-435
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• 1994

For recycling of the waste tires, polyurethane binder mixed with the scrapped rubber powders which obtained from tread part of waste tire. This study covered the effect of the binder contents on the mechanical properties of the blend. We also studied the change of the properties after aging on properties compared with those of before aging. The curing reaction of the binder was also investigated in this study. We obtained conclusions the suitable binder content was 15phr in this system.

• Structural Engineering and Mechanics
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• 제51권3호
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• pp.403-412
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• 2014

In this paper, enhancement of corrosion and chloride resistance of high performance self compacting concrete (SCC) through incorporating nanosilica into the binder has been investigated. For this purpose, different mixtures were designed with different amounts of silica fume and nano silica admixtures. Different binder contents were also investigated to observe the binder content effect on the concrete properties. Corrosion behavior was evaluated by chloride penetration and resitivity tests. Water absorption and capillary absorption were also measured as other durability-related properties. The results showed that water absorption, capillary absorption and Cl ion percentage decreased rather significantly in the mixtures containing admixtures especially blend of silica fume and nano silica. By addition of the admixtures, resistivity of the SCC mixtures increased which can lead to reduction of corrosion probability.

• 한국세라믹학회지
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• 제44권1호
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• pp.6-11
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• 2007

The rheological properties of slag cement pastes by effect of particle size distribution of binder were investigated using a Rheostress 1 rheometer (Haake) with a cylindrical spindle and the relationship between fluidity particle size distribution using the Rosin-Rammler equation. Samples are combined the two types of slag powder and OPC, fine slag particles sized Elaine specific surface area $8,000cm^2/g$, coarse slag particles sized Elaine specific surface area $2,000cm^2/g$, intermediate OPC particles $3,450cm^2/g$, used to search for the combination that would yield the best quality product. The all flow curves which were measured by rheometer showed hysterisis and could be classified into 4 types. When the combination was based on a ratio of 15-20 vol% fine particles, 40-50 vol% intermediate particles, 30-40 vol% coarse particles of the total volume, a high fluidity and low yield-strength was achieved. The Rosin-Rammler function can explain aboved correlation flow curve types. On type 1, the n-value had a correlation with plastic viscosity however the blend of type 2 and 3 showed consistent n-value regardless of plastic viscosity. In addition, the blend in type 4 tended to a rise in fluidity according to the increase of the n-value.

• 대한기계학회논문집
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• 제14권1호
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• pp.54-71
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• 1990

본 연구에서는 세라믹 기계요소를 생산하기 위한 기초연구로서, 세라믹 사출 성형에 대한 기본적인 가공조건과 여러변수들을 고찰하고 가능한한 최대의 세라믹체적 비를 갖고 세라믹입자와 완벽한 융합을 이룰수 있는 최적의 결합제 구성과 세라믹입자 의 충진비율에 따른 혼합체(mixture)의 유동특성을 규명하여 사출성형의 적부를 판별 함과 동시에 그 훈련된 상태를 고찰하여 이후의 공정에서 불균일에 의한 결함이 발생 하지 않도록 정확한 성형조건을 제시하고자 한다. 또한 사출성형에 가장 적절한 혼 합체를 선정하여 탈지공정 및 소결을 행하고 각 공정에서의 부품의 수축률 및 결함을 관찰하여 그 결함의 원인 및 제거방법에 대하여 논의할 것이다. 본 논문에서 제시한 각 공정 및 고찰은 중요한 모든 변수들의 경향 및 특성을 다루었으며 정밀한 세라믹부 품의 신속한 생산을 위한 기초 연구로서 실제 산업체에 응용될 수 있을 것으로 사료된 다.

• 한국농공학회지
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• 제29권4호
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• pp.132-141
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• 1987

The objective of the study was to obtain the compressive the tensile and the fleniril strengthes, thermal resistance, chemical resistance and fire resistance of the reclaimed plastic corcrete in order to investigate the feasibility as a new construction material This reclaimed plastic concrete is a compositive material which is composed of sand and blend of 50% of LDPE(Low density polyethylene) and 50% of HDPE (High density polyethylene) which are inexpensive and easy to reclaim. The results obtained in the study are summarized as follows: 1. As the binder content ranging from 20 to 40 % increase, the compresie, the splitting tensile and the flexural strengthes were increased. The compressive strenzth of the specimen tested was the highest and flexural strength the next and tensile strength the lowest 2. The compressive, the tensile and flexural strengthes of specimens made of fine sand were higher than those of coarse sand. The compressive, the tensile and the flexural strengthes of specimens made of high pressure molding were higher than those of low pressure molding. 3.In comparison with different additives, the specimens with carbon black was excellent and B. H. T. good and ferric oxide poor for thermal resistance. 4. In relationship between the flexural strength with varying temperature from -23$^{\circ}C$ to 80$^{\circ}C$. The flexural strengthes were decreared as temperature increased at 25 %, 30 % and 35 % of binder contents, respectively. Especially at 60$^{\circ}C$, the flexural strength was significantly decreased. 5. The decrement of flexural strengthes and the weight losses after 7 days immersion in acid or alkali solutions were not significant. 6. Fire resistance of the reclaimed plastic concrete was not significantly influenced by the contents of sand. However, the fire resistance of the reclaimed plastic concrete was depend upon melting and ignition properties of the binder itself. Therefore. a proper selection of the binder and the fire retardant are recommended in arder to improve fire resistance of the reclaimed plastic concrete.

• Advances in concrete construction
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• 제6권1호
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• pp.29-45
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• 2018

This paper investigates the effect of inclusion of glass fibers on mechanical and fracture properties of binary blend geopolymer concrete produced by using fly ash and ground granulated blast furnace slag. To study the effect of glass fibers, the mix design parameters like binder content, alkaline solution/binder ratio, sodium hydroxide concentration and aggregate grading were kept constant. Four different volume fractions (0.1%, 0.2%, 0.3% and 0.4%) and two different lengths (6 mm, 13 mm) of glass fibers were considered in the present study. Three different notch-depth ratios (0.1, 0.2, and 0.3) were considered for determining the fracture properties. The test results indicated that the addition of glass fibers improved the flexural strength, split tensile strength, fracture energy, critical stress intensity factor and critical crack mouth opening displacement of geopolymer concrete. 13 mm fibers are found to be more effective than 6 mm fibers and the optimum dosage of glass fibers was found to be 0.3% (by volume of concrete). The study shows the enormous potential of glass fiber reinforced geopolymer concrete in structural applications.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2006년도 춘계학술논문 발표대회 제6권1호
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• pp.89-92
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• 2006

To investigate the properties of high flowing and high strength concrete with crushed sand and fly ash for CFT structure, many batches were performed by a trial-error method. In the experiment W/B was set up three levels as 0.25, 0.30 and 0.35. Also the variables of the experiment were a substitution ratio of fly ash, a blend ratio of crushed sand and the ages of specimens(3, 7, 28 days). The results of this study are summarized as the follows; 1) The effect a substitution ratio of fly ash on the compressive strength was not consistent with age. For twenty-eight day compressive strength, the best result was come out when cement was substituted by 10% of fly ash. 2) The decrease of the water binder ratio, the increase of compressive strength and elastic modulus. Also the relationship is very similar to the case of a normal concrete

• Elastomers and Composites
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• 제31권2호
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• pp.95-103
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• 1996

Nowadays, recycling of waste materials is one of great attention among all industries. Especially, the waste tires become a significant problem with increasing in a number of automobiles. For recycling of the waste tires, a polyurethane binder was mixed with the scrapped rubber powders obtained from tread part of the waste tire. This study covered the effect of processing conditions;curing temperature and curing time;on the mechanical properties of the blend. We also compared the experimental results from labors-tory scale with those from scale-up.

• 한국건설순환자원학회논문집
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• 제6권1호
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• pp.25-35
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• 2018

본 연구에서는 카올린과 플라이애시의 두 종류의 결합재를 혼합하여 알칼리 활성화시킨 후, 경화체의 강도 및 미세구조 분석을 수행하였다. 이를 위해, 경화된 시험체에 대해 압축강도, X선 회절분석(XRD), 열중량(TG) 분석 및 SEM/EDS 분석을 실시하였다. 카올린-플라이애시 혼합 결합재는 카올린 혼합에 관계없이 모든 경화체에 대해서 재령에 따라 압축강도가 증가하는 경향을 나타냈으며, 플라이애시 중량에 대한 카올린의 혼합비가 증가할수록 압축강도는 낮아지는 것으로 나타났다. XRD 분석 결과에서는 제작된 모든 시험체에 대해서 플라이애시 및 카올린의 원재료에 함유된 구성광물 이외에 새로운 결정질 물질 형성은 확인되지 않았지만, 이에 반해 TG 분석에서는 모든 시험체 내에서 N-A-S-H gel이 반응생성물로 형성된 것을 알 수 있었다. 모든 시험체들의 내부는 대체적으로 치밀하지 않은 것으로 나타났으며, 카올린 치환율에 따른 강도 발현의 차이가 있음에도 불구하고, 내부의 조직구조에서 뚜렷한 차이는 없는 것으로 나타났다. 본 연구에서 보여준 반응생성물의 Si/Al가 낮을수록 시험체의 강도가 상대적으로 높은, Si/Al와 강도와의 상관관계에 따라, 반응생성물의 Si/Al가 낮도록, 즉 사용되는 결합재의 $Al_2O_3$의 용해도를 높일 수 있는 화학적 첨가제가 고려된다면, 카올린-플라이애시 혼합 결합재의 강도 개선 효과를 기대할 수 있을 것으로 판단된다.