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        검색결과 13

        1.
        2018.02 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to investigate the removal characteristics of heavy metals and sulfate ion from acid mine drainage by porous zeolite-slag ceramics (ZS ceramics) that was prepared by adding wood flour as pore-foaming agent while calcining the mixtures of natural zeolite and converter slag. The batch test showed that the removal efficiency of heavy metals by pellet-type porous ZS ceramics increased as the particle size of wood flour was decreased and as the weight mixing ratio of wood flour to ZS ceramics was increased. The optimal particle size and weight mixing ratio of wood flour were measured to be 75 ㎛ and 7∼10%, respectively. The removal test with the porous ZS ceramics prepared in these optimal condition showed very high removal efficiencies: more than 98.4% for all heavy metals and 73.9% for sulfate ion. Relative to nonporous ZS ceramics, the increment of removal efficiency of heavy metals by porous ZS ceramics with 75 ㎛ and 10% wood flour was 5.8%, 60.5%, 36.9%, 87.7%, 10.3%, and 57.4% for Al, Cd, Cu, Mn, Pb, and Zn, respectively. The mechanism analysis of removal by the porous ZS ceramics suggested that the heavy metals and sulfate ion from acid mine drainage are eliminated by multiple reactions such as adsorption and/or ion exchange as well as precipitation and/or co-precipitation.
        2.
        2017.09 서비스 종료(열람 제한)
        This study investigated the properties of lightweight foamed concrete by using surfactant and synthetic foaming agent, lightweight aggregate. The effects of foaming agent types and replacing ratio of lightweight aggregate on the compressive strength, density and pore structure of the concrete were investigated. This study showed the improvement of important properties of lightweight foamed concrete. Lower pore distribution and correspondingly higher compressive strength values were reached. Also, synthetic foaming agent had more positive effect on the strength of foamed concrete.
        3.
        2017.04 서비스 종료(열람 제한)
        This study was conducted to examine the workability of LEFC in relation to the types and the mix ratio of different foaming agents. The foam agents act as lightweight aggregates in the concrete matrix and provide an alternative to obtaining the adequate strength level for the foam concrete. The results of the test showed that the synthetic foam agents were able to act properly as replacements for the lightweight aggregates.
        4.
        2017.04 서비스 종료(열람 제한)
        This study investigated the properties of foamed concrete by using surfactant foaming agent and synthetic foaming agent. The effects of foaming agent types on the compressive strength, density and pore structure of the concrete were investigated. The samples were assessed by XRD analysis and simultaneous SEM was used to study their pore distribution. This study showed the improvement of important properties of foamed concrete. Lower pore distribution and correspondingly higher compressive strength values were reached. Also, synthetic foaming agent had more positive effect on the strength of foamed concrete.
        5.
        2017.01 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to examine the workability of LEFC in relation to the types and the mix ratio of different foaming agents. The foam agents act as lightweight aggregates in the concrete matrix and provide an alternative to obtaining the adequate strength level for the foam concrete. The results of the test showed that the synthetic foam agents were able to act properly as replacements for the lightweight aggregates.
        6.
        2017.01 KCI 등재 서비스 종료(열람 제한)
        This study investigated the properties of foamed concrete by using surfactant foaming agent and synthetic foaming agent. The effects of foaming agent types on the compressive strength, density and pore structure of the concrete were investigated. The samples were assessed by XRD analysis and simultaneous SEM was used to study their pore distribution. This study showed the improvement of important properties of foamed concrete. Lower pore distribution and correspondingly higher compressive strength values were reached. Also, synthetic foaming agent had more positive effect on the strength of foamed concrete
        7.
        2016.04 서비스 종료(열람 제한)
        This study is corroborated as a fundamental resource to develop lightweight foamed concrete. Weight of unit volume decreased until 0.8% dosage of foaming agent is put cement paste. After that, Mechanical properties of cement paste with foaming agent is verified to use FEM analysis based on picture image. Finally, It is compared with compressive strength of experiment and estimation from picture image.
        8.
        2016.04 서비스 종료(열람 제한)
        The properties of bubble in lightweight concrete shows a difference depending on the ingredient and amount of foaming agent. To select foaming agent which is suitable for the purpose, it is essential to conduct a basic study to find the right properties of bubble.
        9.
        2014.04 서비스 종료(열람 제한)
        The energy consumption by buildings approximately reaches 25% of total korea energy consumption. The greatest part in the buildings of the energy consumption is building facade. but a few research projects on concrete comprising more than 70% of outsider of buildings has been tried. This research structural insulation concrete what improved insulation performance using Micro Form Admixture.
        10.
        2013.10 서비스 종료(열람 제한)
        While carrying out a series of study for improving the durability of High Volume Admixture Concrete using the ERCO, we found that the resistance of freezing and thawing declined due to the decrease of air amount in concrete when using the ERCO. In order to solve the problem, we carried out an experiment using the DEM. As a result of that, it did not affect the basic characteristic of concrete, and the problem of decreasing air amount caused by using the ERCO is also considered to be solved by securing the target air amount.
        11.
        2013.10 서비스 종료(열람 제한)
        The energy consumption by buildings approximately reaches 25% of total korea energy consumption. The greatest part in the buildings of the energy consumption is building facade. but a few research projects on concrete comprising more than 70% of outsider of buildings has been tried. This research structural insulation concrete what improved insulation performance using micro form admixture and lightweight aggregate.
        12.
        2013.04 서비스 종료(열람 제한)
        In this study, we investigated the physical properties and thermal behaviors of specimens that applied different mixing ratios of foaming agent to evaluate the possibility of use in the structural elements. We proposed the estimating equation for compressive strength of each mix having different ratio of foaming agent. We also confirmed that the density of cement matrix is decreased as the mixing amount of foaming agent increase up to 0.6% of foaming agent mixing ratio which was observed by SEM. Based on porosity and compressive strength of control mortar without foaming agent, we built the estimating equations of compressive strength for mortars with foaming agent
        13.
        2013.03 KCI 등재 서비스 종료(열람 제한)
        최근 전세계는 급격한 기후조건과 환경변화에 의해 냉난방 에너지 사용이 증가되고 있으며 이는 화석 연료 사용량 증가와 함께 CO2 배출량 상승, 지구 온난화 등 환경과 에너지에 대한 수많은 문제를 유발하고 있어 세계 각국은 온실가스 배출 및 에너지 소비 감소를 위한 대응책을 마련하고 있다. 우리나라 또한 정부의 '저탄소 녹색 성장' 및 '친환경 주택 건설기준 및 성능' 등의 정책을 선포하는 등 건물 부분에 있어 환경과 에너지 관리에 대한 노력을 하고 있다. 우리나라의 총 에너지 소비량 중 건물 부문이 차지하는 비율은 약 25%에 달하며 다른 산업 분야에 비해 연간 에너지 소비 증가율이 높은 편이다. 건물에서 에너지 손실이 가장 큰 부위는 외피로서, 이 부분의 에너지 손실을 감소하기 위한 연구가 활발히 진행되고 있으나 이는 대부분 창호 및 단열재를 사용한 연구이며 건물 외피의 70% 이상을 차지하고 있는 콘크리트에 대한 연구는 미미한 실정이다. 따라서 건물의 에너지 손실을 최소화하기 위해서는 콘크리트 자체에서 단열성능을 확보할 수 있어야 하며 이에 대한 연구가 필요하다. 따라서 본 연구는 콘크리트의 단열성능을 확보하면서 구조용으로 사용이 가능한 콘크리트를 개발하기 위한 실험을 진행하였다. Test 1의 실험결과로써, Micro Foam Admixture (MFA)를 사용한 콘크리트는 슬럼프 경시변화가 개선되었으며, MFA의 혼입율을 증가할 경우 압축강도는 감소되고 열전도율은 증가되는 결과를 나타내었다. Test 2의 실험결과에서는 물시멘트비 변화시 물시멘트비 증가에 따라 압축강도는 감소하였고 열전도율은 증가하였다. 그러나 잔골재율 변화에 대한 물성 및 열적 특성은 큰 차이를 나타내지 않았다.