• Title/Summary/Keyword: Old concrete

검색결과 350건 처리시간 0.029초

하수관 누수에 의해 발생되는 공동 주변 지반의 거동에 대한 가소성유동화토의 보강효과 (Effects of Reinforced Pseudo-Plastic Backfill on the Behavior of Ground around Cavity Developed due to Sewer Leakage)

  • 오동욱;공석민;이대영;유용선;이용주
    • 한국지반환경공학회 논문집
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    • 제16권12호
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    • pp.13-22
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    • 2015
  • 노후된 하수관의 누수로 인해 발달된 지하공동은 지표침하를 발생시키고 그로 인한 포장재의 취성파괴를 유발시킨다. 이러한 도심지 지반함몰 현상은 최근 5년간 그 빈도수가 꾸준히 증가하고 있는 추세이다. 도심지 지표면은 대부분 아스팔트 또는 콘크리트로 포장이 되어 있어 지하공동의 발생에 따른 지반침하 또는 함몰을 예측하기 어려운 실정이다. 따라서 이 연구는 파손된 하수관의 누수로 인해 발생되는 지하공동의 진행에 따른 지표침하량, 지표면의 영향범위 등 지반거동 및 하수관의 침하를 유한요소해석을 이용하여 분석하였다. 또한 침하 또는 함몰이 발생된 지반을 보강하기 위한 보강재로 가소성유동화토를 사용하였을 때의 보강효과를 수치해석 프로그램을 이용하여 비교 분석하였으며 강도정수 산정을 위해 가소성유동화토의 직접전단시험을 수행하였다.

이명박정부 국가정보화전략 실현을 위한 법제개선방향과 함의 - 선진지식정보사회 구현을 위한 법제개선의 일반원칙 고찰을 중심으로 - (A Study on Legislative Implication and Legislation Principles of Achieving the Lee Myung-bak Administration's National Infomatization Strategy)

  • 방동희
    • 정보화정책
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    • 제17권1호
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    • pp.23-42
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    • 2010
  • 이 논문은 이명박정부의 국가정보화전략 선포와 더불어 국가정보화기본계획을 실현하는데 있어서 법제개선방향의 함의와 일반원칙을 살피는 것을 목적으로 작성되었다. 우리나라의 정보화는 법제도적 관점에서 1986년 제정된 전산망보급확장과이용촉진에관한법률의 '전산망의개발보급과이용등에관한기본계획'기, 1995년 제정된 정보화촉진기본법의 '정보화촉진기본계획'기, 그리고 2009년 국가정보화기본법에 따른'국가정보화기본계획'기 로 크게 3기로 구분할 수 있다. 금번 이명박정부의 국가정보화기본계획은 제3기 국가정보화의 시작을 알리는 것으로 이에 대한 법제개선의 방향과 함의를 찾는 것은 무엇보다도 중요할 것으로 판단된다. 본 논문은 우선 이명박정부가 제시한 국가정보화기본계획에 근거하여 법제개선의 거시적 방향을 살피고, 이를 통해 함의와 일반원칙을 도출하는 순으로 전개하였다. 제3기의 첫출발에 있어서 본 논문에서 제시한 정보화 법제개선의 함의와 일반원칙이 이명박정부의 국가정보화기본계획을 성공적으로 실현하는데 입법정책적 기준으로 일조될 수 있기를 기대한다.

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생석회의 팽창압 발현에 미치는 첨가제 및 양생온도의 영향 (The Influences of Additives and Curing Temperature on the Expansion Pressure of Calcium Oxide Hydration)

  • 김원기;소정섭;김훈상;김홍주;이원준;신진호
    • 한국세라믹학회지
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    • 제44권9호
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    • pp.529-535
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    • 2007
  • Calcium oxide has been used as a demolition agent in fracturing rocks and old concrete structures, etc. With the agent, demolition work can be done in safety without a noise, vibration and any other pollution, since high expansive pressure is obtained gradually by only mixing the agents with water and pouring the slurry into boreholes. But application of the non-explosive demolition agent is a time-consuming job, especially in winter. Essentially, this problem is related to the reaction rate of calcium oxide with water. This study examines the influence of additives such as cement and anhydrite on expansion pressure of calcium oxide at different curing temperatures. The expansion pressure of calcium oxide began to increase steadily with the rise of the curing temperature. When mixing calcium oxide alone with water, blown-out shot occurred. But as additives were added to calcium oxide, the reaction of calcium oxide delayed and the expansion pressure showed gradual increment. Especially, anhydrite showed a superior delaying effect than cement on the reaction of calcium oxide.

Quality of Recycled Fine Aggregate using Neutral Reaction with Sulfuric Acid and Low Speed Wet Abrader

  • Kim, Ha-Seog;Lee, Kyung-Hyun;Kim, Jin-Man
    • 한국건축시공학회지
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    • 제12권5호
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    • pp.490-502
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    • 2012
  • The use of recycled aggregate, even for low-performance concrete, has been very limited because recycled aggregate, which contains a large amount of old mortar, is very low in quality. To produce a high-quality recycled aggregate, removing the paste that adheres to the recycled aggregate is very important. We have conducted research on a complex abrasion method, which removes the component of cement paste from recycled fine aggregate by using both a low-speed wet abrasion crusher as a mechanical process and neutralization as chemical processes, and well as research on the optimal manufacturing condition of recycled fine aggregates. Subsequently, we evaluated the quality of recycled fine aggregate manufactured using these methods, and tested the specimen made by this aggregate. As a result, it was found that recycled fine aggregates produced by considering the aforementioned optimal abrasion condition with the use of sulfuric acid as reactant showed excellent quality, recording a dry density of 2.4 and an absorption ratio of 2.94. Furthermore, it was discovered that gypsum, which is a reaction product occurring in the process, did not significantly affect the quality of aggregates. Furthermore, the test of mortar using this aggregate, when gypsum was included as a reaction product, showed no obvious retarding effect. However, the test sample containing gypsum recorded a long-term strength of 25.7MPa, whereas the test sample that did not contain gypsum posted a long-term strength of 29.4MPa. Thus, it is thought to be necessary to conduct additional research into the soundness and durability because it showed a clear reduction of strength.

유시티 도래에 따른 도시민 생활양식 변화가 도시공간에 미치는 영향 (A Study on the Effect of Changes in Lifestyle on Urban Space with the Advent of the U-City)

  • 이진희;신동빈
    • Spatial Information Research
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    • 제20권5호
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    • pp.37-47
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    • 2012
  • 이 연구의 목적은 유시티에 따른 생활양식 및 도시공간의 변화를 분석하여 이를 반영한 도시 정책 방향을 제안하는 것이다. 유시티에서의 도시공간 변화 분석에 있어서는 도시민 설문조사를 통한 생활양식 변화를 예측하여 추론하는 행태적 접근 방법을 사용하였다. 분석 결과 도심을 주요 활동공간으로 하는 도시기능에 있어 통행량 및 이용의 감소와 입지 선호도의 변화로 도심 집중화 약화와 도시의 외연적 확산이 예상되었다. 개별 용도에 있어서는 통행량과 이용의 감소에 따라 규모나 개수가 축소될 것으로 예상되었으며, 기존 공간의 재편에 있어서는 특히 공공공간에 있어 유비쿼터스 기술을 활용하여 다양한 도시활동을 수행할 수 있는 다목적 공간으로의 변화가 전망되었다. 앞으로 유시티가 정착하면 도시의 공간구조와 시설별 수요가 도심과 비도심에 따라 변화가 예상되므로 이를 반영한 도시계획이 필요하다. 동시에 효율적이고 유연한 도시공간이 조성될 수 있는 발판이 마련되어야 한다.

Sweet BV 시술이 Rat의 중추신경계에 미치는 영향 - 기능관찰 종합평가를 이용하여- (Effects of Sweet Bee Venom on the Central Nervous System in Rats -using the Functional Observational Battery-)

  • 안중철;권기록
    • 대한약침학회지
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    • 제14권3호
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    • pp.19-45
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    • 2011
  • Objectives: This study was performed to analyse the effects of Sweet Bee Venom(Sweet BV-pure melittin, the major component of honey bee venom) on the central nervous system in rats. Methods: All experiments were conducted at Biotoxtech Company, a non-clinical studies authorized institution, under the regulations of Good Laboratory Practice (GLP). Male rats of 5 weeks old were chosen for this study and after confirming condition of rats was stable, Sweet BV was administered in thigh muscle of rats. And checked the effects of Sweet BV on the central nervous system using the functional observational battery (FOB), which is a neuro-toxicity screening assay composed of 30 descriptive, scalar, binary, and continuous endpoints. And home cage observations, home cage removal and handling, open field activity, sensorimotor reflex test/physiological measurements were conducted. Results: 1. In the home cage observation, there was not observed any abnormal signs in rats. 2. In the observation of open field activity, the reduction of number of unit areas crossed and rearing count was observed caused by Sweet BV treatment. 3. In the observation of handling reactivity, there was not observed any abnormal signs in rats. 4. In the observation of sensorimotor reflex tests/physiological measurements, there was not observed any neurotoxic signs in rats. 5. In the measurement of rectal temperature, treatment of Sweet BV did not showed great influences in the body temperature of rats. Conclusions: Above findings suggest that Sweet BV is relatively safe treatment in the central nervous system. But in the using of over dose, Sweet BV may the cause of local pain and disturbance of movement. Further studies on the subject should be conducted to yield more concrete evidences.

프랭클린(Franklin)의 사회구성주의 모델 관점으로 본 한국의 노인주택 맥락 (The Context of Housing for the Old Age in Korea with Perspective of Franklin's Social Constructionism Model)

  • 유병선;전경화;홍형옥
    • 가정과삶의질연구
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    • 제22권1호
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    • pp.103-114
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    • 2004
  • This study was performed by the literature review on housing of the aged in Korea with social constructionism perspective. This kind of research may be utilized as a theoretical framework for performance of any systems of housing for the aged. In terms of structural context, the value of conventional custom of filial piety thoughts and duty for family are being collapsed, which nay be suitable to the change of society, should be considered for positive acceptance of changes in ideology. In terms of institutional context, a method to grope for housing for the aged should be established through amicable cooperation between organizations of legalization concerned. In terms of organizational context, there is no organization that exclusively concern housing for the aged until now, thus, development of concrete manual is required for jobs of service in current department of policy for the aged. In terms of operational context, the service may include the understanding of characteristics of the aged and design of housing may also change the service of administration, and as cooperation in the local community care systems may change the service to the aged in the field. Connection of these services and operation of these organizations nay be required in the field to manage housing. Finally in terms of intersubjective context, as the form and method of housing management service is important, with understanding of the social meaning and importance on the role of manager.

Single-dose Toxicity of Water-soluble Ginseng Pharmacopuncture Injected Intramuscularly in Rats

  • Yu, Junsang;Sun, Seungho;Lee, Kwangho;Kwon, Kirok
    • 대한약침학회지
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    • 제18권2호
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    • pp.76-85
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    • 2015
  • Objectives: Radix Ginseng has been traditionally used as an adaptogen that acts on the adrenal cortex and stimulates or relaxes the nervous system to restore emotional and physical balance and to improve well-being in cases of degenerative disease and/or old age. Radix Ginseng has been used for a long time, but the safety of ginseng pharmacopuncture needs testing. This study was done to analyze the single-dose toxicity of water- soluble ginseng pharmacopuncture (GP) intramuscular injections in rats. Methods: All experiments were performed at Biotoxtech, an institution authorized to perform non clinical studies under the regulations of Good Laboratory Practice (GLP). Each group contained 10 Sprague-Dawley rats, 5 males and 5 females. GP was prepared in a sterile room at the Korean Pharmacopuncture Institute under regulations of Good Manufacturing Practice (GMP). GP dosages were 0.1, 0.5 and 1.0 mL for the experimental groups; normal saline was administered to the control group. The animals general condition was examined daily for 14 days, and the rats were weighed on the starting day and at 3, 7 and 14 days after administration of the pharmacopuncture. Hematological and biochemistry tests and autopsies were done to test the toxicological effect of GP after 14 days. This study was performed with approval from the Institutional Animal Ethics Committee of Biotextech. Results: No deaths were found in this single-dose toxicity test of intramuscular injections of GP, and no significant changes in the general conditions, body weights, hematological and biochemistry tests, and autopsies were observed. The local injection site showed no changes. Based on these results, the lethal dose was assumed to be over 1.0 mL/animal in both sexes. Conclusion: These results suggest that GP is relatively safe. Further studies, including a repeated toxicity test, are needed to provide more concrete evidence for the safety of GP.

Sweet Bee Venom의 rat를 이용한 4주 반복 근육시술 독성시험 (Study of four weeks repeated-dose toxic test of Sweet Bee Venom in rats Original Articles)

  • 권혜연;권기록
    • 대한약침학회지
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    • 제14권1호
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    • pp.5-24
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    • 2011
  • Objective: This study was performed to analyse four weeks repeated -dose toxicity of Sweet Bee Venom (SBV-pure melittin, the major component of honey bee venom) in rats. Methods: All experiments were conducted under the regulations of Good Laboratory Practice (GLP) at Biotoxtech Company, a non-clinical study authorized institution. Male and female rats of 5 weeks old were chosen for the pilot study of four weeks repeated-dose toxicity and was injected at the level of 0.56 mg/kg body weight (eighty times higher than the clinical application dosage as the high dosage), followed by 0.28 and 0.14 mg/kg as midium and low dosage, respectively. Equal amount of normal saline was injected as the control group every day for four weeks. Results: 1. No mortality was witnessed in all of the experiment groups. 2. All experiment groups appealed pain sense in the treating time compared to the control group, and side effects such as hyperemia and movement disorder were observed around the area of injection in all experiment groups, and the higher dosage in treatment, the higher occurrence in side effects. 3. Concerning weight measurement, neither male nor female groups showed significant changes compared to the control group. 4. Concerning to the CBC and biochemistry, all experiment groups didn't show any significant changes compared to the control group. 5. Concerning weight measurement of organs, experiment groups didn't show any significant changes compared to the control group. 6. To verify abnormalities of organs and tissues, those such as cerebellum, cerebrum, liver, lung, kidney, and spinal cords were removed and we conducted histologocal observation with H-E staining. Concerning the histologocal observation of liver tissues, some fatty changes were observed around portal vein in 0.56 mg/kg experiment group. But another organs were not detected in any abnormalities. 7. The proper high dosage of SBV for the thirteen weeks repeated test in rats may be 0.28 mg/kg in one time. Conclusion: Above findings suggest that SBV is relatively safe treatment medium. Further studies on the subject should be conducted to yield more concrete evidences.

폐고속국도의 생태복원 방안 -영동선 192.4K(인천) 지점을 중심으로- (A Study on the Method of Ecological Restoration at the Abandoned Expressways - Focusing on the 192.4k(Incheon) Young-Dong Expressway -)

  • 조동길;최재용;전용철
    • 한국환경복원기술학회지
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    • 제13권5호
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    • pp.38-50
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    • 2010
  • Expressways are often upgraded by widening the lanes and/or by reshaping the roads to be more linear for faster travel time. However, during the process of improving the route of the expressways, the areas where the old expressways used to be are often unused and abandoned. When these neglected sites are left alone, they often become dump sites causing pollution and impacting the surrounding environment. Therefore, it is important to restore the abandoned expressway sites to its full natural beauty. In this study, the abandoned expressway at the Soksa interchange in Pyungchang county, located in Kangwon province was studied for establishing the model of ecological restoration project. Considering the characteristics of the site, the target flora species was chosen to be Quercus species and the target fauna species as amphibians. After the target species were carefully chosen, each species' habitat requirements were studied in order to figure out the appropriate methods toward habitat restoration specifically for these species. In addition, to determine the most efficient method toward restoration of abandoned expressways, the study utilized the planting hole techniques, the crack techniques, and the colonization techniques. In terms of the spatial organization, public education program is incorporated at the main entrance area and the programs for experimenting, and developing vegetation and habitat restoration techniques are placed in the vicinity. In the master plan-to provide natural ecosystem at the site-ASCON (asphalt concrete) was removed first, then plans for restoration including species' habitat restoration were established. Furthermore, the project included plans for improving water quality polluted through non-point source considering the surrounding nearby road and farm lands. Finally, the study established a planning process that will experimentally apply to the abandoned expressway restoration method. In the future, there will be a continuous monitoring of the methods applied to verify if the restoration methods are effective. Also, new restoration techniques should be available according to a variety of abandoned expressways' characteristics.