• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2009년도 추계 학술논문 발표대회
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• pp.127-131
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• 2009

The purpose of this study is to provide fundamental data on chloride diffusion from lightweight aggregate concrete by utilizing crushed stone-powder. Accordingly, the study performed experiments using concrete aggregates of Crushed Aggregate (CG), Single-sized Lightweight Aggregate (SLG), Continuous Graded Lightweight Aggregate (CLG), and using water-binder ratio of 0.4, 0.5, 0.6, and using binder of FA and BFS. The chloride diffusion coefficient is calculated after experiment based on NT BUILD 492. Diffusion coefficient of SLG and CLG were little bit higher than CG Concrete, but the difference is meaningless. Also, chloride diffusion coefficient indicates that it is highly affected by water-binder ratio, and it decreases with the decrease in water-binder ratio. The admixture substitution indicates decrease only with water-binder ratio of 0.4 for FA15% case, but admixture substitution indicates decrease with all levels of ratio for FA10 + BFS20% which means more appropriate. According to the analysis result of chloride diffusion from lightweight aggregate concrete, crushed stone-powder utilized lightweight aggregate concrete indicates higher chloride diffusion coefficient than CG concrete, which is not a significant difference, and can improve resistance through water-binder ratio and admixture substitution.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 가을학술발표대회논문집
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• pp.33-34
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• 2023

Currently, research on construction materials using industrial by-products is being conducted in the Inhan construction industry due to CO₂ emissions during the cement production process and a shortage of aggregates. Among these, research has been conducted to use steel furnace slag as an aggregate by reducing the reactivity of free-CaO, which has the characteristic of expanding through open storage, aging, and rapid cooling. However, research on the use of powder as a cement admixture or substitute is insufficient. Therefore, this study aims to analyze the properties of fresh mortar using steel furnace slag powder. The mixing ratio of steel furnace slag powder was divided into three levels: 0, 20, and 40 (%), and the test items were flow and unit weight. The experimental results showed that as the mixing ratio of steel furnace slag powder increased, flow and unit weight tended to increase. Therefore, it is expected to have a positive effect on improving workability or strength as a cement admixture.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2006년도 춘계학술논문 발표대회 제6권1호
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• pp.63-69
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• 2006

In a traditional society, building materials were developed fulfilling the requirements of conveniences and functionalities such as safety, construction work, durability and economical efficiency. However, as the concern about environmental or users' health issues has been elevated recently, research and development about eco-friendly material are alto vigorously promoted further In addition, thanks to the steady growth of domestic industry, the amount of discharged industrial by-product is getting increasing. However, its recycling rate remain at low level as most industrial by-products are filled up in the land, which worsen the environmental pollution. Zeolite powder is cement admixture and is expected to have constraining effect of factors causing symptoms of inhabitants in a new house and alleviates the amount of discharged harmful elements emitted from hardened cement.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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• pp.193-196
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• 2005

In this study, the purpose is to suggest the data on mixing ratio which effects on the carbonation of concrete by replacing various admixture such as silica fume, fly ash, slag powder. Thus, we have experimented the accelerated test on the carbonation related to hardened body of the concrete which was admixed by slag powder, silica fume, fly ash and it was cured for 4 weeks in carbonation accelerator after 28 days curing water. The result of this experiment showed that carbonation speed increased highly when admixtures be used to replacing by growing of admixture ratio. especially, the test sample which was replaced with silica fume 15$\%$ and slag powder 40$\%$, was promoted highly to carbonation.

• 한국건설순환자원학회논문집
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• 제7권3호
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• pp.262-270
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• 2019

본 논문에서는 페로니켈슬래그 미분말 및 혼화재의 복합사용에 따른 모르타르의 강도 및 내구성 평가를 실시하였다. 페로니켈슬래그 및 생석회, 석고, 염화칼슘을 OPC 대비 20%로 치환하여 복합사용 하였으며, 휨강도 및 압축강도, SEM분석을 통한 모르타르의 강도 평가를 실시하였다. 석고를 혼화재로 사용하였을 때 초기강도 발현은 보이지만, 페로니켈슬래그 및 생석회, 염화칼슘을 혼화재로 복합사용 하였을 때 강도발현과 강도증진효과가 극대화 되었으며, 혼화재의 적절한 복합사용이 미세한 공극 채움과 밀도개선효과로 인해 강도와 내구성 개선에 영향을 주는 것으로 판단된다. 또한 화학적침식저항성 및 XRD 분석을 통해 혼화재의 적절한 복합사용은 수화 생성물인 Muscovite의 함량에 따라 강도가 증가하는 경향을 보였고, 규산염은 산 알칼리에는 용해되지 않으므로 화학적 침식 저항 성능이 OPC에 비하여 우수한 것으로 사료된다.

• 한국세라믹학회지
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• 제46권6호
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• pp.633-638
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• 2009

Lightweight materials were fabricated using glass abrasive sludge, bottom ash and slag powder in this study. This study tried to draw the correlation between physical properties and internal pore of lightweight material. The content of bottom ash and slag powder was from 10% to 50% and firing temperature from $760{^{\circ}C}\;to\;800{^{\circ}C}$ in rotary kiln. The lightweight material containing bottom ash or slag powder had a specific gravity of $0.21{\sim}0.70$ at particle size $2{\sim}4$ mm. Replacement ratio of the admixture increasing with specific gravity increased. Fracture strength of panel made with various lightweight materials was $32{\sim}55\;kgf/cm^2$ and flexural strength was $11{\sim}18\;kgf/cm^2$. Fracture strength increased by 72% and flexural strength was 63% compared with reference. Thermal conductivities of panel was $0.07{\sim}0.11W/m{\cdot}k$. The water absorption ratios of panel with lightweight materials containing bottom ash were $1.8{\sim}2.8$% and slag powder were $2.65{\sim}2.8$%. Excellent results on resistant of water absorption.

• 콘크리트학회지
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• 제15권5호
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• pp.17-23
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• 2003

• 한국건축시공학회지
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• 제7권2호통권24호
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• pp.59-65
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• 2007

Recently, due to the increase of high-rise buildings construction, many researches for making harden of concrete earlier and remove of forms faster are being performed to reduce construction period. In this study, we compared and analysed the early strength properties of mortar according to the kinds and replacement ratio of mineral admixture to select the kinds and replacement ratio of mineral admixture of high early strength concrete. For this purpose, mortar mixtures according to the kinds(FA, MK, ZR, BFS, DM) and replacement ratio(0, 2, 4% by volume of sand) of mineral admixture were selected. From our test data, early-age compressive strength decreased in accordance with the increase of replacement ratio of fly-ash(FA) & blast furnace slag powder(BSF) and, in case of addition admixture, early-age compressive strength of with containing 4% appeared higher compared with containing 2%.

• 한국구조물진단유지관리공학회 논문집
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• 제4권1호
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• pp.85-92
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• 2000

Recently. there has been steadily applied in high-performance concrete using powder type admixture in construction field. It has been reported that high-performance concrete is likely to cause the spalling by fire more seriously due to the dense microstructure. In this paper, spalling properties of high-performance concrete with the kinds of admixture and polypropylene(PP) fiber contents are presented. According to the experimental results concrete contained no PP fiber take place in the form of the surface spalling, regardless of admixture. Concrete contained more than 0.05% of PP fiber and admixture do not take place the spalling, however the concrete using silica fume do spalling. Concrete using blast furnace slag have good performance in spalling resistance. It is found that residual compressive strength has 60~70% of its original strength when spalling do not occur. Although specimens after exposed at high temperature are cured at water for 28days, they do not recover their original strength.

• 한국건축시공학회지
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• 제6권4호
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• pp.93-98
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• 2006

Admixture materials are used in mixing concrete or mortar to improve quality and performance of the concrete. This study examines the potential use of talc as a substitute for cement, the benefits of recycling waste resources for economical efficiency and quality improvement of concrete. The test was carried out by replacing the plain mix with fine grains of talc at the rate of 10%, 20%, and 30%. Talc was divided into three groups depending on the degree of pulverizing. For wet concrete, porosity, slump, bleeding per unit, and setting time by penetration resistance were measured; similarly, for dry concrete, strength and watertight Property were tested. Test results showed that the amount of bleeding and setting time could be shortened, but the strength and watertight proofing severely deteriorated. However, at the replacement rate of 10%, talc showed equal performance with the plain at all degrees of pulverization, which suggests its potential use as admixture material.