• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1989년도 가을 학술발표회 논문집
• /
• pp.25-30
• /
• 1989

In this paper, morter and concrete specimens made with four cements were immersed in Mgcl2, MgSO4 Solution and artifical Seawater which was corresponded with Seawater. The hydration products of immersed cement pastes were looked over by using SEM, EDS and X-ray diffraction method. The results show that the concrete made with domestic flyash cement and blast-frrnace slag cement is superior to that of ordinary portland cement in resistance to chloride and sulphate solution. Especially, it is found that the attack of Cl-ion on the concrete plays an important role of the deterioration of concrete.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1996년도 가을 학술발표회 논문집
• /
• pp.387-393
• /
• 1996

The purpose of this study is analyze the properties of undispersed concrete according to replacement of the ratio of fly-ash. The test results show that as the ratio of flyash replacement which increasing fluidity but the amounts of air content, suspended solid and pH values dicreased and setting time is delayed. The ten persent replacment of fly-ash has less water pollution and high compressive strength value than other ratio of fly-ash replacement.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1997년도 봄 학술발표회 논문집
• /
• pp.163-169
• /
• 1997

The sea water resistance of cement and concrete must be considered when it is used for construction on the seashore of in the ocean. The concrete specimens using seven type of cements such as ordinary Portland cement, moderate heat Portland cement, sulfate resistance Portland cement, type A. B. C Portland blastfurnace slag cement and Portland flyash cement were immersed for 10 years in seawater in Kunsan. This study proved that moderate heat Portland cement, sulfate resistance Portland cement, type A Portland blastfurnace slag cement had higher resistance for seawater.

• 한국산업안전학회:학술대회논문집
• /
• 한국안전학회 2002년도 춘계 학술논문발표회 논문집
• /
• pp.65-70
• /
• 2002

난연$\cdot$다기능성 복합성형체는 기계부품, 구조물, 차량, 선박, 항공기 및 산업 분야에 널리 사용되고 있다. 안전성이 확보된 신소재 개발의 일환으로서 본 연구진은 난연특성, 정전기 방지특성, 내식특성의 기능성 복합성형체 개발을 수행해 왔으며, 본 연구에서는 Recycled PE, Phenolic resin 및 PPS resin과 같은 재활용 제품에 고기능성을 부여하기 위하여 용도에 따라 alumina, silica, flyash 등의 무기질 filler를 최대 70wt(%) 이상으로 고충진한 복합 폴리머 성형체를 개발하고자 하였다.(중략)

• 기술사
• /
• 제46권2호
• /
• pp.44-50
• /
• 2013

The treatment of city life wastes is headache problem. Now, only small portion of burnable wastes is burnt at modern process incinerators, the other large portion is buried in the soil by landfill method. The burnable wastes will be increased year by year. The dioxin, the cancer-causing agent, produced by incineration of wastes influences harmful effect to national human health. The new idea of burnable wastes treatment is using the city life wastes as auxiliary fuel of fluidizing bed combustion boiler of large scale coal-fired power plant. The dioxin-free treatment of burnable wastes is sucessfully achieved by burning the wastes, in flyash storm at fluidizing bed combustion boiler.

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

• Geomechanics and Engineering
• /
• 제10권5호
• /
• pp.677-687
• /
• 2016

Industrialization and urbanization are the two phenomena that are going relentless all over the world. The consequence of this economic success has been a massive increase in waste on one hand and increasing demand for suitable sites for construction on the other. Owing to the surplus raw materials and energy requirement needed for manufacturing synthetic fibers, applications of waste fibers for reinforcing soils evidenced to offer economic and environmental benefits. The main objective of the proposed work is to explore the possibilities of improving the strength of soil using fly ash waste as an admixture and Human Hair Fiber (HHF) as reinforcement such that they can be used for construction of embankments and land reclamation projects. The effect of fiber content on soil - fly ash mixture was observed through a series of laboratory tests such as compaction tests, CBR and unconfined compression tests. From the stress - strain curves, it was observed that the UCC strength for the optimised soil - flyash mixture reinforced with 0.75% human hair fibers is nearly 2.85 times higher than that of the untreated soil. Further, it has been noticed that there is about 7.73 times increase in CBR for the reinforced soil compared to untreated soil. This drastic increase in strength may be due to the fact that HHF offer more pull-out resistance which makes the fibers act like a bridge to prevent further cracking and thereby it improves the toughness which in turn prevent the brittle failure of soil-flyash specimen. Hence, the test results reveal that the inclusion of randomly distributed HHF in soil significantly improves the engineering properties of soil and can be effectively utilized in pavements. SEM analysis explained the change of microstructures and the formation of hydration products that offered increase in strength and it was found to be in accordance with strength tests.

• 한국구조물진단유지관리공학회 논문집
• /
• 제22권6호
• /
• pp.182-188
• /
• 2018

최근 우수한 전기전도도와 넓은 비표면적을 갖는 탄소나노튜브(CNT)를 활용하여 고강도 및 고내구성 콘크리트의 생산을 위한 연구가 많은 연구자들에 의하여 활발히 이루어지고 있다. CNT의 혼입을 통한 콘크리트의 고강도에 대한 연구가 주를 이루고 있으나, 그 외의 연구는 미흡한 실정이다. 이에, 본 연구에서는 CNT 첨가량에 대한 시멘트 복합체의 역학성능 및 발열성능에 대한 평가를 실시하였다. 낮은 물-바인더 비를 기반으로 하는 시멘트-플라이애시 배합에 대하여, 바인더 중량대비 0.2% 및 0.5%의 CNT 첨가에 따른 재령별 압축강도, 수화특성분석을 위한 미소수화열 분석, 페이스트 내 CNT의 분산 및 주변 수화물과의 관계를 규명하기 위한 SEM분석, 기준전극 삽입을 통한 발열실험 및 열 중량 분석을 실시하였다. CNT 첨가량의 증가에 따라 발열성능은 증가하며, CNT가 첨가되지 않은 기준 배합 CNT가 첨가된 배합의 경우 동등수준의 역학성능을 갖는 것으로 나타났다.

• 한국환경보건학회지
• /
• 제25권3호
• /
• pp.23-28
• /
• 1999

Phosphate removal through adsorbent, such as activated alumina, powdered aluminum oxide, flyash, blasted furnace slag and other materials, is commonly and widely practiced. The purpose of this study was to improve the removal efficiency of phosphorus in waste sludge earned at seafood processing factories. To investigate the utility and the feasibility of this sludge disposal process, experiment was carried out with a batch process. As a result, phosphate removal appears to increase with increasing adsorbent does, but shows no changes at an adsorbent does over 5g/l. With increasing ratios of initial phosphate concentration to adsorbent does, the amount of removed phosphate is increased while phosphate removal(%) is decreased. Wasted sludge, treated with zinc chloride chemically, represented a better efficiency than the untreated activated sludge and zinc chloride itself, when they reacted with phosphate solution.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1992년도 가을 학술발표회 논문집
• /
• pp.100-105
• /
• 1992

While there are many researches in high-strength concrete recently, average strength required is the level of 400kg/$\textrm{cm}^2$ 28days compressive strength yet. For the effective using of high strength concrete, high strength concrete of 600 to 800kg/$\textrm{cm}^2$ 28days compressive strength must be accepted, But in this high strength concrete, due to much cement content, there are the problems of high hydration heat, high viscosity and economical efficiency. To solve these problems, it is suggested the method that replacement some of cement content as flyash up-to-dately. Therefore, the aim of this study is to develop high strength concrete of 800kg/$\textrm{cm}^2$ 28days compressive strength containing fly ash. This paper is the part I that analyze the testing results of fresh concrete in various aspects.