• 한국재료학회지
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• 제14권5호
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• pp.358-362
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• 2004

$Si_3$$N_4$ ceramics have been identified as one of the promising structural ceramics. This study has been carried out to investigate of the synthetic behaviors of $Si_3$$N_4$ derived from domestic silica-stone by direct nitriding method. The silicon nitridation reaction has been studied in the temperature range of $1300～1550^{\circ}C$. Below the $1400^{\circ}C$, the nitriding rate was measured to be 16%. For the temperatures higher than the $1400^{\circ}C$, $\beta$-$Si_3$$N_4$ phase was formed mainly, and the nitriding rate showed above 98%. With the increasing of sample weight of silicon powder, the nitriding rate and $\beta$-$Si_3$$N_4$ phase increased at $1400^{\circ}C$ for 2 hours. The shape and particle size of$ Si_3$$N_4$ powder synthesized at $1400^{\circ}C$ for 2 hours showed the irregular angular-type and 10 $\mu\textrm{m}$, respectively.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1993년도 가을 학술발표회 논문집
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• pp.167-172
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• 1993

In domestic, there are not adequate admixtures for concrete now, so the study on that is required deeply, Accordingly the purpose of this study is to analyze the application possibilities of Natural Zeolite and Mud Stone as admixtures for concrete through comparing the compressive strength prorerties of mortar mixed with imported Silica Fume those mixed with domestic Zeolite and Mud Stone. As the results from this study, the optimum displacement rate of Silica Fume, Zeolite and Mud Stone is 15%, 5~10%, 15% respectively. In Zeolite and Mud Stone, the compressive strength is higher in proportion as the powder is fine. Consequentely, the application possibility the application possibility of Zeolite and Mud Stone is very sufficient as admixtures for concrete.

• 동의생리병리학회지
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• 제18권4호
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• pp.1159-1162
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• 2004

We studied on the production of the ceramic by the mineral-Oriental medicine and the property of the clean active water depositting on the ceramic stone. The results are as follows: We properly mixed of maifanshi, mica, ochre, and added to a small amount cinnabar, and therefore formed the ceramic stone. By the plasticity process and the irradiating magnetic force recovered the disappeared a part of constitutent elements. The recovered effects were become higher the freshness, maintenance, deodoriztion, clean water. As well as having the ability on capture of the notoxious heavy metal on human. The ceramic powder were mixed proper dose maifanshi, mica. And the powder had ionization, absorption, adhesion by the plasticity process and magnetic force. The clean active water of depositting on the ceramic stone during 24hours were observed significant the content of micro element, dissolved oxygen, abstraction on Herbs.

• 한국분말재료학회지
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• 제10권1호
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• pp.15-20
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• 2003

Hybrid $A1_2O_3-TiC$ ceramic particle reinforced 6061 and 5083 Al composite powders were prepared by the combination of twin rolling and stone mill crushing process, followed by consolidating processes of cold compaction, degassing and hot extrusion. The composite bar consists of lamellar structure of ceramic particle rich area and matrix area, in which the hybrid was decomposed into each TiC of about $3-4\mutextrm{m}$ and $AI_2O_3$ particles of about $1-2\mutextrm{m}$ in diameter. It also found that fine $Mg_2Si$ precipitates of about 30 nm were embedded in the matrix, which have grains of about 3 $\mutextrm{m}$. Higher UTS was measured at the 5083 composite bar compared to the conventionally fabricated composite, due to again refinement effect by the rapid solidification. No particle was shown to form in the interface between the matrix and reinforcement, whereas carbon was diffused into the matrix.

• 한국건설순환자원학회논문집
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• 제6권4호
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• pp.103-111
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• 2012

압축강도 50 MPa이상의 압출성형 시멘트 패널은 고온고압 증기양생으로 생산된다. 고온고압 증기양생에서 요구 강도를 얻기 위해서는 시멘트에 포함되어 있는 CaO와의 반응에 필요한 적정량의 $SiO_2$를 공급하는 것이 관건이다. $SiO_2$의 공급원으로 가장 널리 사용되는 원료는 규석분인데, 이는 환경파괴를 전제로 하기 때문에 친환경적인 제품 생산을 위하여 본 연구에서는 규석분을 대신하여 폐석분을 활용한 시멘트 2차 제품을 생산하고 이에 대한 압출성과 물리적인 특성비교를 실시하였다. 이를 위하여 화성 석산에서 채취한 폐석분을 건조 파쇄한 후 이를 규석분 사용량의 최대 50%까지 치환하여 압출성 및 물리적 특성 실험을 수행하였다. 실험결과 평균 입경은 폐석분과 규석분의 크기가 유사하였으나 물리적 특성은 규석분을 폐석분으로 단순 치환하였을 경우, 대부분 낮게 발현되었다. 따라서 폐석분을 활용할 경우 수화활성을 위한 첨가제 등의 활용이 필요할 것으로 판단된다.

• 콘크리트학회논문집
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• 제26권3호
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• pp.277-285
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• 2014

이 연구는 현장에서 사용하는 재료의 품질 및 계량오차, 현장조건 등에 따라 병용계 자기충전 콘크리트의 유동특성에 영향을 미치는 변동요인의 범위를 실험적으로 규명하기 위한 것이다. 병용계 자기충전 콘크리트의 재료는 벨라이트 시멘트와 석회석 미분말을 사용한 벨라이트계 및 슬래그 시멘트와 석회석 미분말을 사용한 슬래그계가 선정되었으며, 선행연구에서 제시된 최적배합 조건을 대상으로 하였다. 변동요인으로 (1) 콘크리트의 온도 3종류, (2) 잔골재의 표면수율 5종류, (3) 잔골재의 조립률 5종류, (4) 고성능AE감수제의 사용량 5종류, (5) 석회석 미분말의 분말도 3종류 등을 대상으로 민감도 시험을 실시하였다. 민감도 시험의 항목은 슬럼프 플로우, 500 mm 플로우 도달시간, V-깔대기 유하시간, U-box 충전성 높이를 대상으로 하였다. 실험 결과, (1) 콘크리트 온도는 $10{\sim}20^{\circ}C$ 범위, (2) 잔골재의 표면수율은 ${\pm}0.6%$ 범위, (3) 잔골재의 조립률 $2.6{\pm}0.2$ 범위, (4) 고성능AE감수제의 사용량은 ${\pm}0.2%$ 범위, (5) 석회석 미분말의 분말도는 $6000cm^2/g$ 범위에서 현장품질을 관리해야 한다. 벨라이트계 및 슬래그계에 따른 차이는 크지 않았지만, 석회석 미분말 및 $C_2S$ 함량이 높은 벨라이트계가 안정적인 경향을 나타내었다. 따라서 이러한 결과를 현장 시공현장에서 병용계 자기충전 콘크리트의 관리방안으로 제안하고자 한다.

• 지질공학
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• 제17권2호
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• pp.279-287
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• 2007

채석장으로부터 원석을 채취하여 건축석재 및 쇄석골재 등으로 가공하는 과정에서 원석의 약 60% 정도가 폐석이나 석분토로 손실되고 있다. 이 중에서 폐석의 일부만이 도로포장용 쇄석골재로 활용되고 있을 뿐 대부분의 석분토는 석재의 가공이나 파쇄공정에서 분말형태로 물에 혼입되어 슬러지탱크에 침전되게 된다. 이러한 석분토가 방류되거나 살포되면 지표나 지중의 공극들이 메워져 지표수의 지중침투, 지하수의 흐름, 공기의 소통 등이 원활하게 이루어지지 않아 생태계에 악영향을 끼칠 수도 있다. 현행 우리나라 폐기물관리법(2003)에 따르면 석분토가 사업장 내에서 발생되는 산업폐기물로 분류되고 있어 대부분을 지중에 매설하고 있는 실정이다. 따라서 석분토의 물성 및 공학특성을 개량하여 효율적 재활용방안의 수립이 필요하다. 이 연구에서는 국내 채석장에서 발생되는 석분토의 개량 및 재활용 가능성을 분석하기 위해 6개 채석장으로부터 시험용 석분토 및 원지반토를 채취한 후, 이를 일정한 비율의 배합비로 제작한 혼합토를 대상으로 여러 토질시험을 실시하였다. 시험결과를 토대로 도로용 재료로서 석분토의 개량 및 재활용 가능성을 검토하였다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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• pp.228-229
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• 2018

In the construction industry, we have set goals such as reduction of greenhouse gas emissions and reduction of energy use. In particular, reduction of CO₂ emissions in the concrete manufacturing process, reduction of industrial waste and industrial wastes into concrete The zero-emission level of reuse as a resource is under review. On the other hand, the cost of stone is expensive due to small quantity production of domestic stone production in order, it is difficult to carry and construct with heavy material, and it takes long time to construct. In order to solve the shortage of supply and demand of natural stone, various kinds of stone powder, artificial stone made by putting stone texture on the surface of mortar or concrete, fiber reinforced plate, tiles and the like are increasingly used. In this study, the artificial stone using slag and recycled aggregate instead of natural stone was fabricated and the strength characteristics were evaluated for its applicability and feasibility.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.871-872
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• 2006

Nowadays the market for diamond tools grows rapidly. The present decline in the price of industrial diamond makes it a commoditised product capable of competing with conventional abrasives. In terms of production volume, the largest group of diamond tools comprises the metal-bonded diamond impregnated tools, such as sawblades, wire saws, and core drills for cutting stone and construction materials, and core bits for mining applications. This article provides a compendious coverage of the powder metallurgy (PM) diamond tool-making routes, and identifies the recent trends towards changing the tool design and composition to render it cheaper and more efficient.

• Advances in nano research
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• 제16권4호
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• pp.375-394
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• 2024

The extensive utilization of concrete has given rise to environmental concerns, specifically concerning the depletion of river sand. To address this issue, waste deposits can provide manufactured-sand (MS) as a substitute for river sand. The objective of this study is to explore the application of machine learning techniques to facilitate the production of manufactured-sand concrete (MSC) containing stone nano-powder through estimating the splitting tensile strength (STS) containing compressive strength of cement (CSC), tensile strength of cement (TSC), curing age (CA), maximum size of the crushed stone (Dmax), stone nano-powder content (SNC), fineness modulus of sand (FMS), water to cement ratio (W/C), sand ratio (SR), and slump (S). To achieve this goal, a total of 310 data points, encompassing nine influential factors affecting the mechanical properties of MSC, are collected through laboratory tests. Subsequently, the gathered dataset is divided into two subsets, one for training and the other for testing; comprising 90% (280 samples) and 10% (30 samples) of the total data, respectively. By employing the generated dataset, novel models were developed for evaluating the STS of MSC in relation to the nine input features. The analysis results revealed significant correlations between the CSC and the curing age CA with STS. Moreover, when delving into sensitivity analysis using an empirical model, it becomes apparent that parameters such as the FMS and the W/C exert minimal influence on the STS. We employed various loss functions to gauge the effectiveness and precision of our methodologies. Impressively, the outcomes of our devised models exhibited commendable accuracy and reliability, with all models displaying an R-squared value surpassing 0.75 and loss function values approaching insignificance. To further refine the estimation of STS for engineering endeavors, we also developed a user-friendly graphical interface for our machine learning models. These proposed models present a practical alternative to laborious, expensive, and complex laboratory techniques, thereby simplifying the production of mortar specimens.