• Journal of Biosystems Engineering
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• 제16권2호
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• pp.178-187
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• 1991

In order to provide fundamental data for the achievement of safe environmental condition, investigation of the actual state of the nutriculture practices in Korea was carried out. The result obtained are summarized as follows. 1. Cultivation area of nutriculture was 6 ha and culture types included deep flow technique(43%), nutrient film technique(45%), gravel culture(6%), chaff charcoal culture(3%) and rockwool culture(3%). 2. Greenhouses were mostly made of pentite pipe frames and covered by polyethylene film, and culture beds were handy combination of cement blocks, concrete and styrofoam, which were not standard products. 3. Development of nutriculture system appropriate to our actual circumstances and improvement of establishments are required. 4. Since there was not farmhouse that performs the environmental measurement and environmental conditions of cultivation were very limited. sensor applied environmental control technology of nutriculture should be developed.

• 한국자원리싸이클링학회:학술대회논문집
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• 한국자원리싸이클링학회 2005년도 추계정기총회 및 제26회 학술발표대회 고분자리싸이클링기술 특별심포지엄
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• pp.203-207
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• 2005

• Computers and Concrete
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• 제10권2호
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• pp.105-119
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• 2012

This paper presents the mix composition and production method that was applied to an extruded Ductile Fiber Reinforced Cement Composite (DFRCC) panel, as well as the flexural performance, represented by deformation hardening behavior with multiple cracking. The effect of fiber distribution characteristics on the flexural behavior of the panel is also addressed. In order to demonstrate the fiber distribution effect, a series of experiments and analyses, including a sectional image analysis and micromechanical analysis, was performed. From the experimental and analysis results, it was found that the flexural behavior of the panel was highly affected by a slight variation in the mix composition. In terms of the average fiber orientation, the fiber distribution was found to be similar to that derived under the assumption of a two-dimensional random distribution, irrespective of the mix composition. In contrast, the probability density function for the fiber orientation was measured to vary depending on the mix composition.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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• pp.625-628
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• 2006

It is known that cement production not only consumes large amount of energy but also contributes substantially to the green house gas emission. Therefore, there is a demand to develope a new technology to produce energy efficient and environmental conscious cements. The most recent, wood wool ceramic board is being applied in various building material field, for example thermal insulating and acoustic absorption material. This paper focused on improvement of alumino-silicate binder's physical properties for wood wool ceramic board. As the result of this experiment, what we could obtain best fitted alumino-silicate binder's properties such as initial setting time, flow and compressive strength of 3 days aged, was 58min, 110% and 66.0Mpa. This result can be applicable to commercial wood wool ceramic board.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 춘계 학술논문 발표대회
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• pp.206-207
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• 2014

Blast furnace slag is one kind of industrial by-product and was utilized with recycled fine aggregates for the manufacture of zero cement mortar. As the blast furnace slag was from different areas, the strength of the specimen using blast furnace slag showed different performances. In this study, blast furnace slag generated in different areas in Korea has been chosen, fundamental performances of the blast furnace slag blended mortar has been tested to evaluate the quality of the blast furnace slag. Results showed that difference for flowability is limited. As the alkali activation of the blast furnace slag, the compressive strength showed different results. The flexural strength showed little difference when the aggregates and types of blast furnace slag changed.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.13-18
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• 2003

The concrete structure can be easily damaged due to alkali-aggregate reaction. The alkali-aggregate reaction is a reaction between the alkalies(K or Na) in cement and an unstable mineral of the aggregates. There are several test methods to identify alkali reactivity of aggregates. In general, crushed stones are tested by petrographic examination, chemical method and 모르타르 바 method. This study tested alkali-aggregate reactivity of crushed stones that has different rock types such as granitic, volcanic, metamorphic and sedimentary rocks. Samples are collected from 12 local aggregate production companies. Alkali-reactivity of various rock types was evaluated by using ASTM C 227 and C 1260, and compared the test results of two test methods.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 춘계 학술논문 발표대회
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• pp.95-97
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• 2012

Recycled aggregate (RA) produced from demolished concrete waste can bring about several problems on concrete performance, when it is used as aggregate for new concrete. Because RA generally has lower quality than natural aggregate due to the residual cement paste attached on RA and various impurities. It is also very difficult to ensure that the quality of RA remains consistent, because generally RA is produced variously. Thus, in concrete recycling, it is extremely important to estimate the risk of the impurities which could affect performances of recycled aggregate concrete (RAC) focusing on the material flow of concrete waste and its recycling. This study suggests an evaluation result to expect the possibility of impurity mixing in RA production procedure. and suggests a risk evaluation model to expect the changes of RAC performances based on conventional data in Japan.

• 상하수도학회지
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• 제30권3호
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• pp.293-297
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• 2016

This study was performed in order to obtain the effect of the compressive strength of the cured product with manufacturing conditions (amounts of fine aggregate and different types of alkali activator). Material which is the basis of the cured product was used for the blast furnace slag, which has a latent hydraulic activity. Consequently, when using sodium hydroxide as the alkali activator, it is possible to obtain a higher compressive strength than using the calcium hydroxide. And also, it can be added a 10% of fine aggregate with blast furnace slag to improve the compressive strength.

• 산업기술연구
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• 제27권A호
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• pp.31-38
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• 2007

Recently produced concrete has a tendency to overcome environmental defects. Porous and planting Eco-concrete requires the neutralization process and enough void in concrete to contain water, to pass air freely, and provides necessary nutrients to vegetation roots. The biological environment in concrete is not suitable for planting because the concrete possesses strong alkali constituent of pH 11-13. This study evaluated the strength and serviceability of concrete as well as the chemical characteristics of concrete mixed by low-grade iron ore left in the abandoned mine and treated by Ammonium monohydrogen phosphate, $(NH_4)_2HPO_4$. Test variables include two kinds of coarse aggregates such as crushed stones and low-grade iron ore, the duration time and the period for neutralization treatment by Ammonium monohydrogen phosphate, $(NH_4)_2HPO_4$, and the proportion ratio of cement, blast furnace slag and silica fume.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1992년도 봄 학술발표회 논문집
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• pp.1-6
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• 1992

The objective of this report is to investigate and analyze the influnce of the different base concrete in consistency for the good production of superplasticized concrete (SPC) on the basis of the experimental results. The principal conclusions are summarized as follows. 1. SPC exhibited only slight bleeding in both cases of low and medium consistency of the base concrete, compared to the conventional concrete, compared to the coventional concrete. 2. SPC lost slump and flow value at a much faster rate than the conventional concrete with an equivalent water/cement ratio and initial consistency. 3. The compressive strength of SPC was fount to be higher than that of base and conventional concrete, and the case of base concrete with medium consistency showed a little more incretment than low consistency