• Title/Summary/Keyword: 알루미나 시멘트

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Characterization of Wood Chip Ash Generated from a Power Plant (열병합 발전소에서 발생한 우드칩 분진에 대한 특성 분석)

  • Bang, Jung Won;Kim, Soo-Ryong;Kim, Younghee;Kim, Mido;Kang, Won-Seok;Cho, Kye-Hong;Kwon, Woo-Teck
    • Resources Recycling
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    • v.26 no.1
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    • pp.11-15
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    • 2017
  • The amount of the wood chip ash is expected to increase continuously as demand of wood chip-based heat and electricity increase. Thus, there is increased interest in wood chip ash utilization. In this study, as a program of utilization in wood chip ash, the physical and chemical properties of wood chip ashes generated from a combined heat and power plant were investigated. The chemical analysis showed that the main contents of wood chip ash are composed of silica, alumina and alkali. A possibility of reuse as secondary cementitious materials was investigated by the analysis of strength activity index, and compared with coal ash. The highest value for Strength activity index of wood chip fly ash was 78% at 90 days curing time. This result revealed that wood chip fly ash has the potential to be utilized as the admixture for cementitious material.

Properties of Alkali-activated Slag-Red Mud Soil Pavement Using Recycled Aggregate (순환골재를 사용한 알칼리활성화 슬래그-레드머드 흙포장재의 특성)

  • Kang, Suk-Pyo
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.4 no.3
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    • pp.276-283
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    • 2016
  • Red mud is an inorganic by-product produced from the mineral processing of alumina from Bauxite ores. the development of alkali-activated slag-red mud cement can be a representative study aimed at recycling the strong alkali of the red mud as a construction material. This study is to investigate the optimum water content, compressive strength, moisture absorption coefficient and efflorescence of alkali-activated slag-red mud soil pavement according to the recycling fine aggregate content. The results showed that the optimum water content, moisture absorption coefficient and efflorescence area of alkali-activated slag-red mud soil pavement increased but the compressive strength of that decreased as the recycled fine aggregate content increased.

Engineering Properties of Sound Absorbing Foamed Concrete Using Bottom Ash Depending on Mix Factors (배합요인에 따른 바텀애시 미분말을 사용한 흡음형 기포콘크리트의 공학적 특성)

  • Kim, Jin-Man;Kang, Cheol
    • Journal of the Korea Institute of Building Construction
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    • v.9 no.5
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    • pp.63-70
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    • 2009
  • This study is part of an ongoing research project on the development of a sound-absorbing lightweight foamed concrete manufactured by a hydro-thermal reaction between silica and calcium. As the silica source, pulverized bottom ash was used, and as several cementitious powders of ordinary portland cement, alumina cement and calcium hydroxide were used. Manufacture of foamed concrete was accomplished using the pre-foaming method to make a continuous pore system, which is the method of making the foam by using a foaming agent, then making the slurry by mixing the foam, water, and powders. The experiment factors are W/B, foam agent dilution ratio, and foam ratio, and test items are compressive strength, dry density, void ratio, and absorption rate, as evaluated by NRC. The experiment results showed that the sound absorption of lightweight foamed concrete satisfied NRC requirements for the absorbing materials in most of the experiments. It is thus concluded that foam ratio was the most dominant factor, and significantly affected all properties of lightweight foamed concrete in this study. W/B rarely affected total void ratio and continuous void ratio as well as compressive strength, and dry density and foam agent dilution ratio also had little effect onalmost all properties. The analysis of the correlation between NRC, absorption time, continuous void ratio, and absorption time showed that the interrelationship of the continuous void ratio was high.

Characteristics of Soil Pavement by Red Mud Content and Binder Type (레드머드 대체율에 따른 결합재별 흙포장재의 특성)

  • Kang, Suk-Pyo;Kang, Hye-Ju;Kim, Jae-Hwan;Kim, Byeong-Ki
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.5 no.1
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    • pp.37-44
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    • 2017
  • Red mud is an inorganic by-product produced from the mineral processing of alumina from Bauxite ores. The development of alkali-activated slag-red mud cement can be a representative study aimed at recycling the strong alkali of the red mud as a construction material. This study is to investigate the optimum water content, compressive strength, water absorption and efflorescence of alkali-activated slag-red mud soil pavement according to binder type. The results showed that the optimum water content, moisture absorption coefficient and efflorescence area of alkali-activated slag-red mud soil pavement increased but the compressive strength of that decreased as the redmud content increased.

The Fundamental Study on Properties of Concrete Using the Garnet with Industrial Wastes (산업부산물인 가네트를 이용한 콘크리트의 성질개선에 관한 기초적 연구)

  • Lim, Byoung-Ho;Park, Jung-Min;Kim, Tae-Gon;Kim, Wha-Jung
    • Magazine of the Korea Concrete Institute
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    • v.11 no.1
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    • pp.183-190
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    • 1999
  • This paper investigated the possibility of appling to concrete through fundamental experiment for garnet, which was industrial wastes generated in kyung pook region, in aspects of development of new materials and recycling of industrial wastes due to shortage of natural resources. Consequently, garnet powder showed the possibility of admixture as showed in the chemical composition because the content of silica and alumina in relation to pozzolanic activity was about 50%. The time of setting was more or less diminished as the increasing of replacement ratio of garnet. In flow test, flow values tended to increase to some degree as the increasing of replacement ratio of garnet. Therefore, application of garnet was expected to improve the workability of concrete. The compressive strength of mortar replaced by garnet was respectively increased as compared with plain mortar and the maximum strength was showed in replaced by 10%, however a little different to the change of W/B ratio. Also, the possibility of admixture to reduce the amount of cement and to improve the property of concrete was showed as the strength of mortar replaced by garnet was comparable to that by existing admixture(silica fume, fly-ash).

A Study on the Characteristics of Bonding Strength by Types of Repair Materials by Mechanical Pressurizing Equipment(MPE) (기계식 가압장비(MPE)에 의한 보수재 종류별 부착강도 특성에 관한 연구)

  • Yu, Hyeong-Sik;Chung, Jee-Seung
    • The Journal of the Convergence on Culture Technology
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    • v.6 no.2
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    • pp.553-560
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    • 2020
  • In the existing research paper, we developed Mechanical Pressurizing Equipment(MPE) that can apply a certain amount of pressure and found out about improving the bonding strength of repair materials constructed in the repair section, and if pressurized, the bonding strength could be increased. In this study, the pressure of Mechanical Pressurizing Equipment(MPE) was changed to 0, 10, 30, 50, and 80 kPa, and the test was conducted to select effective pressure by measuring the flexural, compressive, and bonding strength of the specimens and deformation of the pressure plate at the age of 3 and 28th days. As a result of the test, 30 kPa was the most efficient pressure for the MPE. After producing the specimen with three types of repair materials with different main components, the bonding strength was measured according to dry and wet conditions, construction site (ceiling, wall and floor), and whether or not pressurized, on the 3rd, 7th, 14th, and 28th, indicating that the repair materials mixed with cellulose fiber was most effective for the MPE.

Surface characteristics for thermal diffusion of FA-BFS-based geopolymer ceramics added alumina aggregate (알루미나 골재를 첨가한 FA-BFS계 지오폴리머 세라믹스의 열확산에 대한 표면 특성)

  • Kim, Jin-Ho;Park, Hyun;Kim, Kyung-Nam
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.29 no.2
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    • pp.61-70
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    • 2019
  • Geopolymer is an eco-friendly construction material that has various advantages such as reduced $CO_2$ emission, fire resistance and low thermal conductivity compared to cement. However, it has not been many studies on the thermal behavior of the surface of the geopolymer panel when flame is applied to the surface. In this study, surface characteristics of hardened geopolymer on flame exposure was investigated to observe its characteristics as heat-resistant architectural materials. External structure changes and crack due to the heat shock were not observed during the exposure on flame. According to the residue of calcite and halo pattern of aluminosilicate gel, decarboxylation and dehydration were extremely limited to the surface and, therefore, it is thought that durability of hardened geopolymer was sustained. Gehlenite and calcium silicate portion was inversely proportional to quartz and calcite and significantly directly proportional to BFS replacement ratio. Microstructure changes due to the thermal shock caused decarboxylation and dehydration of crystallization and it was developed the pore and new crystalline phase like calcium silicate and gehlenite. It is thought that those crystalline phase worked as a densification and strengthening mechanism on geopolymer panel surface.