• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2016년도 춘계 학술논문 발표대회
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• pp.203-204
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• 2016

In this research, it used cement power and reduction slag, which generates high hydration heat in hydration reation without heat cure below -5℃ degree. Purpose of final research is preventing freezing and thawing by making the compressive strength 5MPa in 3days below zero temperature due to own heat of concrete. and it is the result of physical characteristic and thermal property evaluation of reduction slag. Because reduction sag generates high hydration heat, compressive strength development is excellent. By generating highly Hydration heat by C₁₂A₇ and C₃A in reduction slag, compressive strength is developed in low temperature. In case of displacing only reduction slag without SO₃, it is indicated that quick-setting occurs by shortage of SO₃. For preventing quick-setting, gypsum is used essentially. According to this research result, in case of using reduction slag and gypsum as a ternary system, Compressive strength developed 5MPa in 3days below zero temperature. It is identified to prevent early frost damage of concrete below zero temperature.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 춘계 학술논문 발표대회
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• pp.210-211
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• 2014

Nowadays, as to reduce the emission volume of CO₂, blast furnace slag has been widely used to replacement of cement. Techniques about using industrial by-products has been extensively studied. For the previous study, blast furnace slag has been used with recycled fine aggregates. In thess study, considering about the different properties of blast furnace slag, as the change of blaine and chemical performances of blast furnace slag, the results of flowability and compressive strength has been analysed.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2013년도 추계 학술논문 발표대회
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• pp.8-10
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• 2013

Inorganic binding material was made by recycled resource and its applicability as pile-filling material was examined. The result was that the material had same liquidity with the liquidity of OPC and high reactivity with site soil. According to dynamic/static loading tests by site test-construction, the inorganic binding material met both design bearing capacity and settlement. Since the inorganic binding material showed same or better performance than OPC, the utilization possibility of the inorganic binding material made of recycled resource as pile-filling material was verified.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 춘계 학술논문 발표대회
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• pp.287-288
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• 2012

In this study, Analyzed the effect of the change in RFA and RCA substitution rate on the concrete containing BS bonding materials but no cement. The findings are as follows. First, the fresh concrete has less slump value and air contents as more RFA and RCA is used. In case of hardened concrete, as more RFA and RCA are used, the higher the compressive strength of concrete becomes. Especially, the compressive strength of concrete which used recycled aggregates only is found to be 2.2 times as high as that of concrete using natural fine and coarse aggregates only. But if the concrete is to be used as the structural concrete having the compressive strength of 13.8 MPa, the alkaline materials and some cement are required to be added.

• Advances in concrete construction
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• 제8권2호
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• pp.127-137
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• 2019

Roller Compacted Concrete (RCC) is a zero slump concrete consisting of a mixture of cementitious materials, sand, dense graded aggregates and water. In this study, an attempt has been made to investigate the effect of aggregate type on strength and abrasion resistance of RCC made by using granulated blast furnace slag (GGBS) as partial replacement of cement. Mix proportions of RCC were finalized based upon the optimum water content achieved in compaction test. Two different series of RCC mixes were prepared with two different aggregates: crushed gravel and limestone aggregates. In both series, cement was partially replaced with GGBS at a replacement level of 20%, 40% and 60%. Strength Properties and abrasion resistance of the resultant mixes was investigated. Abrasion resistance becomes an essential parameter for understanding the acceptability of RCC for rigid pavements. Experimental results show that limestone aggregates, with optimum percentage of GGBS, perform better in compressive strength and abrasion resistance as compared to the use of crushed gravel aggregates. Observed results are further supported by stoichiometric analysis of the mixes by using basic stoichiometric equations for hydration of major cement compounds.

• 한국재료학회지
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• 제1권2호
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• pp.93-98
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• 1991

The as-grown $YBa_2Cu_3O_{7-x}$ superconducting thin films on MgO(100) substrate have been prepared by a reactive coevaporation method. The superconducting transition temperature, surface morphology and crystalline quality were examined as a function of the substrate temperature ranging from $450^{\circ}C$ to $590^{\circ}C$. From the reflection high energy electron diffraction (RHEED) analysis, it was found the film consisted of almost amorphous phase with a halo pattern deposited at the substrate temperature of $450^{\circ}C$. The film deposited at the substrate temperature of $510^{\circ}C$ consisted of polycrystalline phase, showing a broad ring pattern. On the other hand, for the film deposited at $590^{\circ}C$, RHEED showed spotty pattern indicating that this film consisted of single crystal phase. It has rough film surface due to the surface outgrowth. The surface outgrowth increased as the substrate temperature increased from $510^{\circ}C$ to $590^{\circ}C$. the surface outgrowth may be due to the anisotropic growth rate. The highest transition temperature obtained in this study was $Tc_{zero}$ of 83K with $Tc_{onset}$ of 88K for the film deposited at $590^{\circ}C$ using activated RF oxygen plasma.

• 한국건축시공학회지
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• 제15권2호
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• pp.161-167
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• 2015

최근, 전 세계적으로는 지구온난화 등 환경문제의 심각성을 인식하여 이산화탄소의 배출량을 줄이는 노력을 경주하고 있다. 이와 관련하여 선행 연구에서는 산업부산물인 RA의 알칼리로 BS의 잠재 수경성 반응을 자극시켜, 무시멘트 조건에서 알칼리 활성(Alkali activation)화 시키는 새로운 메커니즘으로 강도 발현성을 확인 바 있다. 본 연구는 제조과정에 따른 석고의 종류 및 소각장에서 발생한 WA 등을 자극제 용도로 추가하여 강도등 품질에 미치는 영향에 대해 검토를 진행하였다. 그 결과, BS에 RA를 사용하는 무 시멘트 모르타르에 WA 0.5%와 AG 20%를 사용할 경우 초기강도는 낮을 지라도 91일강도는 OPC강도이상으로 발휘 되어 양호한 결과를 얻을 수 있었다.

• 한국건축시공학회지
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• 제14권3호
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• pp.252-258
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• 2014

최근에 저탄소녹색성장 및 OPC 절감의 요구에 따라 BS와 같은 산업 부산물을 많이 사용하고 재건축의 증가 및 건설폐기물 발생량이 많아지면서 RA 사용 확대하게 되며, RA 및 무 시멘트 결합재 관심 증대 되고 있다. 무 시멘트 결합재와 RA의 활용을 모두 만족시키기 위하여, RA와 철강 산업 부산물인 BS을 혼합함으로써, 100% 순환자원만을 활용하여 무 시멘트 상태에서 강도발현성을 확인한 바 있다.이에 본 연구는 OPC를 사용하지 않고, BS과 RA 및 CS를 사용하여 모르타르를 제조함으로써 기존 강알칼리를 투입하여 제조하는 지오폴리머 모르타르(Geopolymermortar)와 또 다른 관점에서 접근하였다. 결과적으로, RFA의 유동성 저하 및 초기강도 저하문제만 해결 될 수 있다면, BS에 CS를 15% 치환하고 RFA골재를 사용하는 무 시멘트 모르타르가 OPC 100%를 사용한 종래의 시멘트 모르타르 만큼의 품질을 발휘할 수 있을 것으로 사료된다.

• 한국산업융합학회 논문집
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• 제24권6_2호
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• pp.873-882
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• 2021

In this study, a study was conducted to develop a system for predicting/responding to black ice occurring on roads in winter. Tests conditions were studied by making models of cement concrete pavement and asphalt concrete pavement. In order to freeze water on the manufactured model package, an tests was conducted at a temperature below zero using a freezer, and the freezing process was photographed using a thermal imaging camera. Black ice is generated when water is present on the road surface and the temperature is below freezing or the road surface temperature is below the dew point temperature. Under sub-zero conditions, the pavement, water, and ice were classified with a thermal imaging camera. As a result of the tests, it was possible to distinguish with a thermal imaging camera at a temperature below freezing in the same freezer due to the difference in the emissivity of the packaging, water, and ice. In the process of changing from water to ice during the tests, it was analyzed that ice and water were clearly distinguished by the thermal imaging camera due to the difference in emissivity and reflectance, so black ice could be predicted using the thermal imaging camera.

• 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.