• 터널과지하공간
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• 제7권2호
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• pp.150-157
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• 1997

Various analytical, empirical and theoretical methods for slope stability assessment were applied on slopes to develop aggregate quarry optimally. Among them are block theory, stereographic analysis, RMR, SMR, limit equilibrium method and maximum likelihood. Test site was estimated that slopes were apt to fail although rock quality was good. Modified direction and dip angle was suggested for stability. To reduce the overbreak and to improve the stability, the vertical blasting was recommended for new subground level.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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• pp.368-371
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• 2004

It analyzes the quality of the fine aggregate which is reproduced through a dry production process with cyclone and a wet production process. The conclusions of the study are as follows. 1. The recycled fine aggregate through the dry production process with cyclone shows the low rate of absorption and impurity content after the cyclone process. It shows that its density is 2.37, absorption rate is 4.8 and stability is $5.1\%$ and less. Therefore, it satisfies the standards of KS F 2573(recycled aggregate for concrete) as the first grade. 2. The recycled fine aggregate through the wet production process shows the low rate of absorption and foreign substance content after the process of wash and dehydration. It shows that its density is 2.40, absorption rate is 3.12 and stability is $3.2\%$ and less. Therefore, it satisfies the standards of KS F 2573(recycled aggregate for concrete) as the first grade.

• 한국건설순환자원학회논문집
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• 제9권3호
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• pp.246-252
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• 2021

초속경 시멘트 모르타르에 KS 기준보다 흡수율이 높고 비중이 낮은 저품질의 순환골재가 혼입되었을 때 모르타르의 기초물성과 부피안정성을 실험적으로 확인하였다. 순환골재를 사용하지 않는 배합은 관련 업체에서 사용하고 있는 일반 보수 모르타르의 것을 따랐다. 라텍스 혼입 및 미혼입 배합에 대해 잔골재에 대해 부피비로 15%, 30% 치환하였으며, 모르타르의 슬럼프, 응결시간, 압축/휨강도, 그리고 밀봉/노출 양생에 따른 길이변화량을 확인해 보았다. 실험 결과 저품질의 순환골재가 사용될 때, 사용하지 않은 경우에 비해 24시간 이내 극초기 강도가 최대 50%까지 감소하거나, 건조수축이 최대 2배 까지 증가할 위험이 있는 것을 확인하였다.

• 한국도로학회논문집
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• 제15권2호
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• pp.73-81
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• 2013

PURPOSES : In this study, various laboratory tests were performed to investigate basic physical properties of the asphalt concrete which uses wasted vinyl aggregates. METHODS : The thermal conductivity, ultrasonic velocity, Marshall stability, flow, indirect tensile strength were measured according to binder content and wasted vinyl aggregate content. An experimental construction was performed to verify construct ability of the asphalt pavement using the wasted vinyl aggregates. RESULTS : The thermal conductivity and ultrasonic velocity decreased showing insulation effect by mixing more wasted vinyl aggregate, whereas stability and flow increased. The void ratio shows similar value regardless of the mixing ratio. The highest indirect tensile strength was measured at 2.5% of wasted vinyl aggregate content. The construct ability was verified by observing the process of mixing, placing, and compaction and the state of the pavement surface. CONCLUSIONS : The basic properties and construct ability of the asphalt concrete using the wasted vinyl aggregates were verified. The temperature according to pavement depth will be measured to verify the insulation effect of the wasted vinyl aggregates. In addition, amount of snowfall, snowmelt area, and ice adhesion strength will be analyzed quantitively.

• 한국건설순환자원학회논문집
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• 제3권4호
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• pp.374-381
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• 2015

화재에 대한 건축물의 내화성능 확보를 위해서는 온도가 상승하더라도 허용범위 이내로 제어하고 탈락이나 손상 등이 발생하지 않아야 한다. 이에 대한 대책으로 부재 외면에 내화모르타르로 마감을 하는 것이 가장 효율적인 방법이다. 내화 마감모르타르는 고온에서 강도변화가 작고 열적으로 안정하며 열전도율이 낮은 경량재료라면 효과적으로 성능발현이 가능할 것이다. 본 연구는 내화 마감모르타르 개발을 위한 연구로 비교적 내화성능이 우수한 플라이애시 및 메타카올린 기반의 알칼리 활성화 결합재와 펄라이트 및 유리 발포 경량골재의 고온 특성에 대해 검토하였다. 실험결과 열전도율이 낮고 고온에서 비교적 안정적인 특성을 발현하여 내화 마감모르타르로 적용이 가능할 것으로 판단된다.

• 한국건축시공학회지
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• 제11권5호
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• pp.442-451
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• 2011

Blast furnace slag is recycled as a high value-added material, while steel slag is difficult to recycle or is recycled as a low-grade filler material due to its expansive characteristics. Its property is caused by the high content of free lime and instable steel oxides. Recently, an innovative and rapid cooling method for melting steel slag has been developed in Korea, which reduces free lime content to a minimum level and increases the stability of steel oxides. However, researches on the long-term stability are not sufficient so far. Therefore, this study, focusing on the electric arc furnace oxidizing slag in the steel slag, aims to investigate the properties of the steel slag aggregate, its long-term volume stability and the engineering strength of mortar, and using it as a fine aggregate. This study result indicated that it was possible for it to be used as concrete aggregate because the volume change of the steel slag appeared to be stable.

• 한국건설순환자원학회논문집
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• 제6권3호
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• pp.199-206
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• 2018

아스팔트의 재활용 기술은 화석연료 감소, 탄소 저감, 포장 성능 개선 등의 장점으로 인해 지난 20년간 선진국의 도로 건설 및 유지관리를 위해 개발되고 적용되고 있다. 상온 재생 아스팔트 혼합물은 상온에서 폐아스콘 순환골재를 물과 유화 아스팔트와 함께 혼합하는 역청재료이다. 본 논문은 폐아스콘 순환골재 혼입율에 따라 알칼리 활성화 채움재를 사용한 상온 재생 아스팔트 혼합물의 특성을 검토하고자 하였다. 그 결과 폐아스콘 순환골재의 혼입율이 증가할수록 상온 재생 아스팔트 혼합물의 마샬 안정도가 감소하고 공극률이 증가하였다. 또한, GR에서 정하고 있는 상온 재생 아스팔트 혼합물의 입도 기준을 모든 골재 혼합 조건에서 만족하였다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 가을 학술발표회 논문집
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• pp.69-74
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• 2002

Incineration method of municipal solid waste is the general method for reduction it's quantity and weight. Municipal solid waste incineration ash is classified two general types of ash : fly ash((MWFA) and bottom ash(MWBA)). MWFA containing a high degree heavy-metal may give rise to a serious environmental trouble. Therefore, this study was carried out to examine utilization of fly ash. In this study, we tried to find the recycling method of fly ash as a environmental-friendly artificial aggregate. The artificial aggregate using fly ash was tested for the various aspects, including physical properties and environmental stability. The qualities of artificial aggregate are similar to it of lightweight aggregate, and the heavy metal leaching concentration are very lower than a limitation of KSLT and EP.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표논문집(II)
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• pp.258-261
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• 1998

Aggregate is cheaper than cement and confers considerable technical advantages on concrete, which has a higher volume stability and better durability than hydrated cement paste alone. and coarse aggregate is the largest particle size out of concrete and is much affect on the fruidity, compaction and non-segregation ability of high flowing concrete. As the compaction, fillingability and shrinkage of high flowing concrete, the volume ratio of coarse aggregate is prescribed by Japanese Architectural Standard Specificateon (JASS 5) : from 0.500 to 0.500㎥/㎥. It is the aim of this study to compare and analysis the fruidity, fillingability and non-segregation of high flosing concrete according to the volume ratio of coarse aggregate of concrete(G/Glim).

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1994년도 가을 학술발표회 논문집
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• pp.235-239
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• 1994

Polymer mortars are mainly used as protective coatings in concrete, reinforced concrete, and more rarely, steel, while polymer concretes represent a new type of structural material capable of withstanding highly corrosive environments. The mechanical properties, chemical stability, and some other useful properties are the reasons research, design, and production organizations. However polymer mortars and polymer concretes have been introduced only recently, and many of their properties are still imperfectly known. And, the main technique in producing polymer concrete is to minimize void volume in the aggregate mass so as to reduce the quantity of the relatively impressive polymer necessary for binding the aggregate. In this study, compressive strength and flexural strength of unsaturated polyester resin concrete are related to quantity of resin and solid volume of aggregate. It was founded that the more solid volume of aggregate increase, the less using quantity of resin decrease with out reducing mechnical properties. When solid volume ratio of aggregate is 70.6%, using quantity of resin is minimized to 10wt.%.