• 한국디지털건축인테리어학회논문집
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• 제12권4호
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• pp.59-66
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• 2012

This study is interested in identifying the effectiveness of alkali-activated fire protection material compounds including the alkali-activator such as potassium hydroxide, sodium silicate and fly ash as the fire resistant finishing materials. Also, this paper is concerned with change in compressive strength and pore structure of the alkali-activated fire protection material at high temperatures. The testing methods of fire protection materials in high temperature properties are make use of TG-DSC and mercury intrusion porosimetry measurements. This study results show that compressive strength is rapidly degraded depending on a rise of heating temperature. Porosity showed a tendency to increase irrespective of specimen types. This is due to both the outbreak of collapse of gel comprising the cement and a micro crack by heating. However, alkali-activated fire protection material composed of potassium hydroxide, sodium silicate and fly ash has the thermal stability of the slight decrease of compressive strength and porosity at high temperature. These thermal stability is caused by the ceramic binding capacity induced by alkali activation reaction by the reason of the thermal analysis result not showing the decomposition of calcium hydrate.

• 대한환경공학회지
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• 제32권6호
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• pp.625-630
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• 2010

본 연구는 발전소등에서 발생하는 중유회를 재활용한 탈취패널 제조시 활성탄, 규조토등의 첨가제를 활용함으로써 포름알데히드 및 톨루엔에 대한 제거성능을 향상시켜 중유회의 탈취패널 원료로서의 사용가능성을 확인하였다. 단일 첨가제를 사용하여 제작된 중유회 재활용 탈취패널의 경우 포름알데히드에 대해서는 93% 이상, 톨루엔에 대해서는 97% 이상의 제거성능을 보였으나 기준 패널에 비하여 압축강도가 27~63% 감소하였다. 반면에 두 가지 첨가제를 여러 가지 비율로 혼합하여 제조된 것 중 활성탄과 규조토가 5 wt%씩 첨가된 패널은 포름알데히드 84%, 톨루엔 96%의 제거성능을 보였으며 압축강도는 기준패널보다 32%증가하였다. 따라서 첨가제의 혼합사용을 통하여 중유회재활용 탈취패널을 제조할 경우 유해가스 제거성능과 패널의 강도를 향상 시키는 것이 확인되었다.

• 한국재료학회지
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• 제26권10호
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• pp.521-527
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• 2016

Geopolymers have many advantages over Portland cement, including energy efficiency, reduced greenhouse gas emissions, high strength at early age and improved thermal resistance. Alkali activated geopolymers made from waste materials such as fly ash or blast furnace slag are particularly advantageous because of their environmental sustainability and low cost. However, their durability and functionality remain subjects for further study. Geopolymer materials can be used in various applications such as fire and heat resistant fiber composites, sealants, concretes, ceramics, etc., depending on the chemical composition of the source materials and the activators. In this study, we investigated the thermal properties and microstructure of fly ash and blast furnace slag based geopolymers in order to develop eco-friendly construction materials with excellent energy efficiency, sound insulation properties and good heat resistance. With different curing times, specimens of various compositions were investigated in terms of compressive strength, X-ray diffraction, thermal property and microstructure. In addition, we investigated changes in X-ray diffraction and microstructure for geopolymers exposed to $1,000^{\circ}C$ heat.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2016년도 춘계 학술논문 발표대회
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• pp.205-206
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• 2016

This study examines the effect of binding material and alkali activator on the rheology characteristics of alkali active mortar quantitatively, and a result is as follows. In the 1/2 slump flow, the higher mixing ratio of the fly ash has been shown to increase the table flow. the reason is that fly ash ball bearing action. When viewed in the consistency curve, the higher mixing ratio of the blast furnace slag powder was higher shear stress.

• Computers and Concrete
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• 제20권6호
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• pp.683-688
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• 2017

This paper presents the experimental investigations on the compressive strength and permeation properties of geopolymer concrete prepared with low calcium fly ash as the primary binder activated with different percentage of Alccofine. The durability aspect was investigated by performing permeable voids and water absorption tests since permeability directly influences the durability properties. The test results show that Alccofine significantly improves the compressive strength and reduces the water permeability thus enhances the durability of geopolymer concrete at ambient curing regime which encourages the use of geopolymer concrete at ambient curing condition thus promising its use in general construction also.

• 한국지반환경공학회 논문집
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• 제23권4호
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• pp.21-27
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• 2022

최근 GGBS 및 Fly ash 등과 같은 산업부산물과 알칼리 자극제를 활용한 알칼리 활성화 시멘트에 대한 연구가 활발히 진행되고 있다. 알칼리 활성화 시멘트는 산업부산물에 알칼리 자극제를 혼합함으로 시멘트를 사용하지 않고 강도를 발휘하는 결합재의 일종으로 대표적인 탄소저감 기술이나, 알칼리 활성화를 위해 사용되는 알칼리 자극제는 고가이며 강알칼리성으로 인한 위험성으로 현장적용에 여러 어려움이 있다. 이에 본 연구에서는 알칼리 자극제의 대체재로 Red mud의 활용방안을 모색하고자 Red mud와 제지회를 결합재로 활용한 CLSM의 유동특성, 강도특성 등의 공학적 특성과 토양오염 발생가능성을 평가하였으며, Red mud와 제지회를 혼합한 CLSM의 적정 혼합비를 제시하였다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 봄 학술논문 발표대회
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• pp.136-137
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• 2021

The soda lime waste glass powder was dissolved in NaOH-4M solution to synthesize an alkaline activator, which was used to activate Class-C fly ash (FA). Compressive and flexural strength tests were conducted to determine the mechanical properties. Archimedes' principle was applied to measure the porosity of samples, (SEM-EDX) and XRD was used to study the microstructure and phase changes of samples. Through Inductive Coupled Plazma technique, the solution was found to increase the concentration of Si as the amount of dissolved glass powder was increased. Owing to the increased concentration of Si in an alkaline solution, the reactivity of FA was accelerated resulting in an increased strength and reduced porosity. Additionally, the dissolution of FA was improved as well as the formation of amorphous phases in the matrix was also enhances with the concentration of increased Si in an alkaline solution.

• 자원리싸이클링
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• 제21권3호
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• pp.28-38
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• 2012

이 논문에서는 시멘트를 전혀 사용하지 않고 결합재로서 플라이애쉬를 100% 사용한 알칼리 활성 콘크리트를 개발할 목적으로 알칼리 활성화제의 화학적 변화에 따른 모르타르의 압축강도에 미치는 영향과 SEM/ EDS 및 XRD 등의 미세구조 분석을 검토하였다. 그 결과, 몰농도가 높을수록 초기강도에 큰 영향을 미치는 것으로 분석되었고, 압축강도의 크기에 비례하여 $Si^{4+}$ 및 $Al^{3+}$량이 용출되었다. 또한 SEM 및 EDS로 조직을 분석한 결과 모르타르의 조직구조에 큰 영향을 미치는 성분은 Al 및 Si 성분이었고, XRD 분석결과 활성화제 성분차이에 따른 세기(intensity)의 차이는 거의 없는 것으로 나타났다.

• 대한화학회지
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• 제56권6호
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• pp.692-699
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• 2012

현 연구의 목적은 변압기 오일에 있는 PCBs의 흡착 제거를 위해 활성탄, 황토, 비산재의 이용 가능성을 탐구하는 것이다. 흡착 실험에서 온도(5, 25, 55), 접촉시간(30분-3일), 흡착제의 양(1, 2.5, 5, 10 g)과 같은 인자들의 영향을 조사하였다. 60분의 흡착평형시간에서 활성탄에 의한 변압기 오일로부터 PCBs의 흡착율이 황토보다 더 우수하였다. 활성탄과 황토의 흡착 평형 데이터는 Freundlich 등온 모델 식에 적합하였다. 5, 25 그리고 $55^{\circ}C$의 온도에서 각 흡착제의 PCBs 흡착 속도상수와 활성화 에너지를 속도 모델을 통하여 알아보았다. 열역학 자료들로부터 변압기 오일/활성탄과 황토 계에서의 PCBs 흡착 공정이 자발적이며 흡열반응이라는 것이 확인되었다.

• Membrane and Water Treatment
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• 제11권3호
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• pp.195-200
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• 2020

In this study, a biocatalyst composite was prepared by immobilizing oxidoreductases onto Cu-activated zeolite to facilitate biochemical decomposition of 4-chlorophenol (4-CP). 4-CP monooxygenase (CphC-I) was cloned from a 4-CP degrading bacterium, Pseudarthrobacter chlorophenolicus A6, and then overexpressed and purified. Type X zeolite was synthesized from non-magnetic coal fly ash using acetic acid treatment, and its surfaces were coated with copper ions via impregnation (Cu-zeolite). Then, the recombinant oxidative and reductive enzymes were immobilized onto Cu-zeolite. The enzymes were effectively immobilized onto the Cu-zeolite (79% of immobilization yield). The retained catalytic activity of CphC-I after immobilization was 0.3423 U/g-Cu-zeolite, which was 63.3% of the value of free enzymes. The results of this study suggest that copper can be used as an effective enzyme immobilization binder because it provides favorable metalhistidine binding between the enzyme and Cu-zeolite.