• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2010년도 춘계 학술논문 발표대회 1부
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• pp.21-23
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• 2010

This study was conducted to draw various decisive elements of a reasonable heat curing method and to examine the importance in deciding a construction method when constructing cold weather concrete. As a result, the items proposed as important elements at the time of decision of a heat curing method included economy, workability, maintainability, insulation capability, reduced construction period and usability. As a result of importance by items under AHP technique, it was found the most important element was insulation capability, followed by reduced construction period and workability. As a result of comparison of a heat supplying and a heat insulation method by dual bubble sheet differed 2 times as much as a heat supplying method, especially the evaluation degree by insulation capability and reduced construction period was high.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.645-650
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• 2003

The purpose of this study is to provide the optimum mix design of cold weather concrete to be placed at the foundation structures in substation. The basic performance tests including slump and slump flow, air content, compressive strength and freezing & thawing resistance were conducted for cold weather concrete by varying with W/C ratios such as 40%, 50% and 60% and air contents such as 3%, 4%, 5% and 6%. The effect on durability of concrete corresponding to the increasing amount of air content and W/C ratio was evaluated and the optimum mix design was recommended. From this study, the concrete mix design containing 6% of air content and 45% of W/C ratio is recommended for the foundation concrete of substation.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2003년도 학술.기술논문발표회
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• pp.7-11
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• 2003

This study investigate the hydration heat history with variation of surface insulating material in cold weather concreting. According to the results, the temperature of concrete lowers below zero in 24hours, so early frost damage occurs in the case of exposure and 1 fold bubble sheet, but the lowest temperature keeps above zero, so a adiabatic effect is very favorable in the case of double bubble sheet and 부직포. Compressive strength of core specimen at 7 and 28 days is highest In the case of double bubble sheet and 부직포. But, considering convenience of construction and economical efficiency, it is thought that the most effective surface insulating material is 1 fold bubble sheet +blanket.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2013년도 춘계 학술논문 발표대회
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• pp.113-114
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• 2013

This study is to investigate the effect of the diameter of reinforcement bars located in an aluminum-form on the temperature histories of the re-bars before placing concrete during a cold weather condition. The diameters of reinforcement bars with 13 mm, 19 mm, 25 mm and 32 mm were prepared for the experimental tests. Results showed that the larger the size of the diameter of the bars, the higher were the temperature drop. However, this study found that its effect on the temperature drop of the bars was insignificant.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2013년도 춘계 학술논문 발표대회
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• pp.71-72
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• 2013

This study investigates the effect of the diameters of reinforcement bars located in an euro-form before placing concrete in a cold weather condition. The diameters of reinforcement bars with 13 mm, 19 mm, 25 mm and 32 mm were prepared for the experimental tests. Results showed that the larger the size of the diameter of the bars, the higher were the temperature drop. However, this study found that its effect on the temperature drop of the bars was insignificant.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.199-204
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• 2000

When fresh concrete is exposed to low temperature, the concrete may suffer from the frost damage at early ages and the strength development may be delayed. To solve such problems of cold weather concreting, admixtures called agent for enduring cold climate are developed to prevent the fresh concrete from being frozen at early ages In this study, the experiments are carried out on several kinds of agent for enduring cold climate to present their performance. According to experimental results, most kinds of agent for enduring cold climate show the satisfactory properties of decreasing the freezing point and acceleating the cement hydration in low temperature environment, which is available for placing concrete in spite of cold weather.

• 한국환경과학회지
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• 제29권7호
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• pp.773-784
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• 2020

In order to protect the lives and property of citizens, the central and local governments are responding by enacting municipal ordinances and regulations as the frequency of extreme weather conditions due to climate change increases and intensity increases gradually. Accordingly, the basic contents and strategies of domestic and foreign policies to cope with cold and heat waves were reviewed, referring to measures suitable for application to the Daegu metropolitan area. In addition, it is intended to provide a policy alternative to Daegu metropolitan area to minimize damage from extreme weather by identifying the current status, characteristics, and future prospects of extreme weather in Daegu metropolitan area. Since the damage caused by the cold wave in Daegu area is not as great as that of other regions, it is urgent to come up with cold wave measures for the health and transportation sectors, and to come up with measures against the heat wave as the damage caused by the heat wave is the most serious in the country. Also we will identify spatial characteristics so that the districts and counties with high vulnerability to extreme weather can be identified and implemented first, and present civic life-oriented facilities and civic action guidelines to overcome cold and heat waves.

• 대기
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• 제33권1호
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• pp.49-59
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• 2023

Blocking refers to a class of weather phenomena appearing in the mid and high latitudes, whose characteristics are blocked airflow of persistence. Frequently found over the Pacific and Atlantic regions of the Northern Hemisphere, blocking affects severe weather in the surrounding areas with different mechanisms depending on the type of blocking patterns. Along with lots of studies about persistent weather extremes focusing on the specific types of blocking, a new categorization using Rossby wave breaking has emerged. This study aims to apply this concept to the classification of blockings over the Pacific and examine how different wave breakings specify the associated cold weather in the Korean peninsula. At the same time, we investigate a strongly developing ridge around the Pacific by designing a new detection algorithm, where a reversal method is modified to distinguish ridge-type blocking patterns. As result, Kamchatka blocking (KB) and strong ridge over the Central Pacific are observed the most frequently during 20 years (2001~2020) of the studied period, and anomalous low pressures with cold air over the Korean Peninsula are accompanied by blocking events. When it considers the Rossby wave breaking, cyclonic wave-breaking is dominant in KB, which generates low-pressure anomalies over the Korean Peninsula. However, KB with anticyclone wave breaking appears with the high-pressure anomalies over the Korean Peninsula and it generates the warm temperature anomaly. Lastly, the low-pressure anomalies are also generated by the strong ridge over the Central Pacific, which persists for approximately three days and give a significant impact on cold surge on the Korean Peninsula.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 추계 학술발표회 제20권2호
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• pp.617-620
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• 2008

최근 대규모 건축물의 등장으로 말미암아 연중 시공이 이루어지고 있으며, 한중 콘크리트 시공시동결에 의한 콘크리트 품질저하의 문제점이 부각되어지고 있는 실정이다. 따라서 본 연구에서는 한중콘크리트의 품질 확보 방안중의 하나로서 포름산-아세테이트산염을 주성분으로 한 무염화형 방동제를 적용한 콘크리트의 품질 및 특성에 대하여 성능 검토를 실시하였다. 포름산-아세테이트산염계 방동제의 적용시험을 수행한 결과, 영하권 외기 양생 조건에서 경화콘크리트 특성은 방동제를 첨가하지 않는 시료에 비하여 모든 재령에서 우수한 강도 발현 특성을 나타내고 있었으며, 장기재령에서도 강도 저하 현상이 발생하지 않았다. 또한 굳지않은 콘크리트의 유동특성 및 경화 콘크리트의 특성을 고려한 결과 결합재의 3.0%내외의 방동제 적용량이 가장 우수한 결과를 나타내었다.

• 한국건설순환자원학회논문집
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• 제7권1호
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• pp.51-59
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• 2012

최근의 초고층건축물의 건설로 인하여 겨울철에 타설하는 한중콘크리트의 문제점을 해결하기위한 노력이 이루어지고 있으며, 본 연구에서는 조기강도 개선을 위한 실험 변수별 배합확인 실험을 통해 조기강도 개선용 콘크리트의 표준배합을 설정하고 각요인별 강도특성을 검토하고자 하였다. 한중콘크리트 실험에서 OPC보다 OPC에 조기강도 특성을 개선한 시멘트와 3종조강시멘트가 우수하였다. 혼화제는 폴리카르본산계 혼화제가 강도발현 특성에 우수한 것으로 나타났으며, 혼화재의 경우 플라이애시의 사용으로 인한 조기강도 발현성능이 불리한 것으로 판단하여 본실험에서는 배제하였고, 강도발현을 위한 최적온도는 $12^{\circ}C$ 이상으로 나타났다.