• 제목/요약/키워드: Quick-setting

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급결제를 이용한 EVA 분말수지 혼입 폴리머 시멘트 모르타르의 초기강도 특성 (Early Strength Properties of EVA Polymer Powder-Modified Mortars with Quick Setting Agent)

  • 조영철;최낙운;이철웅;양석우;소양섭
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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    • pp.309-312
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    • 2005
  • Admixture compounds for shortening setting time and accelerating early strength development of EVA polymer powder-modified mortars were made by mixing various quick setting agents. As a result, the quick setting agents contribute to strength development of the mortars in the early curing age of 168h or less. In the viewpoint of early strength development of EVA polymer powder-modified mortars, an quick setting agent content of 20$\%$ is recommended. Early strength of EVA polymer powder-modified mortars expresses the excellent strength with 5$\%$, 10$\%$ of rates of polymer mixing. The rate of polymer mixing was able to be adjusted and flexural strength which is a predeterminded initial strength was also able to satisfy 3MPa(s).

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Blast furnace slag의 표면 활성화 특성 및 quick-setting 특성에 관한 연구 (A Study on the Surface Activation and Quick-setting Characteristics of Blast Furnace Slag)

  • 이웅걸;송명신;강현주;최훈;송영진
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2010년도 춘계 학술대회 제22권1호
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    • pp.273-274
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    • 2010
  • 본 연구에서는 고로슬래그의 초기 강도의 증진과 응결지연의 단점을 개선하기 위해 고로 슬래그 및 석고가 혼입된 고로 슬래그를 대상으로 pH 변화에 따른 고로 슬래그의 표면 활성화의 특성과 quick-setting 특성에 관하여 연구하였다.

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국내 패션산업의 Quick Response System 추진 현황과 문제점 (Implementation Issues to Quick Response System in Korean Fashion Industry)

  • 신상무
    • 한국전자거래학회지
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    • 제3권1호
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    • pp.175-194
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    • 1998
  • The purpose of this study is to examine the current status of Quick Response adoption, and to recognize the implementation problems of QR system in the Korean fashion industry. We reviewed the theoretical background of QR system, analyzed the current status of QR adoption, and identified critical issues to implement the system in our fashion business environment. Previous literatures and information gained from communication service organizations were used for this study The major problems recognized are lack of inter-organizational information network, closed supply channels, non-standardization of QR implementation, and low level of information technology usage including KAN, POS, and EDI. Strong mutual partnership between streams for shared common goals and clear QR mind setting of top management with commitment to information sharing are considered needed for the successful adoption of QR system in domestic fashion industry.

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균열자기치유 기술을 적용한 지하철 터널 누수공사 (Repair methods of water leakage cracks using crack self-healing technologies for subway tunnels)

  • 안태호;방신영;김정미;심광보
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2015년도 춘계 학술논문 발표대회
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    • pp.15-16
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    • 2015
  • In this research, the application of repair methods of water leakage cracks using self-healing technologies for subway tunnels is presented. In order to apply crack self-healing water stop agents and quick setting agents in subway tunnels, laboratory and field tests were performed based on various previous researches. Especially, this study focused on development of crack repair materials and their new repair methods. Therefore, various repair materials were examined for new repair materials with self-healing capability applied to crack sealing method and to patching repair method.

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환원슬래그를 사용한 모르타르의 저온에서의 초기동해 방지에 관한 연구 (The Study of Experiment on Preventing Frost Damage at Early Age of Mortar in Low Temperature using Reduction Slag.)

  • 김형철;최현국;민태범
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2016년도 춘계 학술논문 발표대회
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    • pp.203-204
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    • 2016
  • In this research, it used cement power and reduction slag, which generates high hydration heat in hydration reation without heat cure below -5℃ degree. Purpose of final research is preventing freezing and thawing by making the compressive strength 5MPa in 3days below zero temperature due to own heat of concrete. and it is the result of physical characteristic and thermal property evaluation of reduction slag. Because reduction sag generates high hydration heat, compressive strength development is excellent. By generating highly Hydration heat by C12A7 and C3A in reduction slag, compressive strength is developed in low temperature. In case of displacing only reduction slag without SO3, it is indicated that quick-setting occurs by shortage of SO3. For preventing quick-setting, gypsum is used essentially. According to this research result, in case of using reduction slag and gypsum as a ternary system, Compressive strength developed 5MPa in 3days below zero temperature. It is identified to prevent early frost damage of concrete below zero temperature.

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Evaluation Method of Hairstyling Materials and its Application to Cosmetic Preparations

  • Abe, Hidetoshi;Iida, Ichiro;Someya, Takao
    • 대한화장품학회:학술대회논문집
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    • 대한화장품학회 2003년도 IFSCC Conference Proceeding Book I
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    • pp.1-12
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    • 2003
  • Instead of sensory evaluation, we designed an evaluation method of the setting function of hairstyling products, based on an original theory focusing on changes in bending stress observed when a load with continuous bending is applied to human hair. Specifically, we developed a device to measure bending stress to quickly and objectively evaluate the condition of human hair, particularly its dynamic properties such as the setting function, following the application of hairstyling products. This device generates a load with continuous bending while applying a pendulum motion to a hair tress, one end of which is anchored. The setting function and holding power of resins of various molecular weight and ionic properties were evaluated using this device. The results demonstrated a close correlation with those obtained by experts' sensory evaluation. The evaluation results of bending stress and holding rate confirmed that the combined use of two different resins could improve the function of setting preparations. Evaluation using this device was able to substitute for sensory evaluation, and offers quick objective evaluation and detection of changes in the holding power of hairstyling products over time. We conclude that evaluation using this device is a promising new method.

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긴급보수용 개질 유화아스팔트 고비율 순환골재를 사용한 상온 아스팔트 혼합물의 성능 평가 (Performance Evaluation of High-RAP Asphalt Mixtures using Rapid-Setting Polymer-Modified Asphalt Emulsion)

  • 권봉주;허재민;한용진;이석근
    • 한국도로학회논문집
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    • 제17권2호
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    • pp.21-30
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    • 2015
  • PURPOSES : The purpose of this study was to evaluate the performance of rapid-setting polymer-modified asphalt mixtures with a high reclaimed asphalt pavement (RAP) content. METHODS: A literature review revealed that emulsified asphalt is actively used for cold-recycled pavement. First, two types of rapid-setting polymer-modified asphalt emulsion were prepared for application to high-RAP material with no virgin material content. The quick-setting polymer-modified asphalt mixtures using two types of rapid-setting polymer-modified asphalt emulsion were subjected to the following tests: 1) Marshall stability test, 2) water immersion stability test and 3) indirect tensile strength ratio test. RESULTS AND CONCLUSIONS : Additional re-calibration of the RAP was needed for laboratory verification because the results of analyzing RAP aggregates, which were collected from different job sites, did not deviate from the normal range. The Marshall stability of each type of binder under dry conditions was good. However, the Type B mixtures with bio-additives performed better in the water immersion stability test. Moreover, the overall results of the indirect tensile strength test of RAP mixtures with Type B emulsions exceeded 0.7. Further research, consisting of lab testing and on-site application, will be performed to verify the possibility of using RAP for minimizing the closing of roadways.

Experimental study on chemical activation of recycled powder as a cementitious material in mine paste backfilling

  • Liu, Yin;Lu, Chang;Zhang, Haoqiang;Li, Jinping
    • Environmental Engineering Research
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    • 제21권4호
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    • pp.341-349
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    • 2016
  • To improve the utilization rate of construction waste as mine backfilling materials, this paper investigated the feasibility of using recycled powder as mine paste backfilling cementitious material, and studied the pozzolanic activity of recycled construction waste powder. In this study, alkali-calcium-sulfur served as the activation principle and an orthogonal test plan was performed to analyze the impact of the early strength agent, quick lime, and gypsum on the pozzolanic activity of the recycled powder. Our results indicated that in descending order, early strength agent > quick lime > gypsum affected the strength of the backfilling paste with recycled powder as a cementitious material during early phases. The strength during late phases was affected by, in descending order, quick lime > gypsum > early strength agent. Using setting time and early compressive strength as an analysis index as well as an extreme difference analysis, it was found that the optimal ratio of recycled powder cementitious material for mine paste backfilling was recycled powder:quick lime:gypsum:early strength agent at 78%:10%:8%:4%. X-ray diffraction analysis and scanning electron microscope were used to show that the hydration products of recycled powder cementitious material at the initial stages were mainly CH and ettringite. As hydration time increased, more and more recycled powder was activated. It mainly became calcium silicate hydrate, calcium aluminate hydrate, etc. In summary, recycled powder exhibited potential pozzolanic activities. When activated, it could replace cementitious materials to be used in mine backfill.