• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.193-194
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• 2012

Construction work is affected by the weather; e.g. snowfall, rainfall and low-high ambient temperature, especially at a site in a severe climate. The influence of the weather is one of the possible reasons for delays in a construction schedule and quality deterioration. To protect the worksite from severe weather conditions, the temporary roof and wall could be installed on the outside of main structures designed in advance and the temporary structures could be took down after a period use. The greater coverage all-weather construction method is applied, the larger the effect. so, it is important and needs that the temporary roof and wall can be widely applied, designed to effectively about structure and layout.

• Journal of the Korea Institute of Building Construction
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• v.13 no.1
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• pp.38-47
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• 2013

When building with concrete in cold weather, an insulation method of heat curing must be determined, and a holistic curing plan that considers the characteristics of structures, the heat loss coefficient of a curing sheet, the joint condition of the curing materials and the quantity of heat produced by a heating apparatus is an essential prerequisite for protection against early frost damage. But on a number of national construction sites, there have been serious problems in cold weather concreting due to the unreliability of the information obtained from practical experience. In the construction field in Japan, there is a specification for heat curing prepared by Japanese Architectural Society, which provides an equation for calculating heat quantity. It is also necessary to adopt a detailed specification for a standard heat curing method that is applicable to all national construction sites. In this study, the effect of bubble sheets on the economic feasibility of cold weather concrete is investigated through a comparison with the blue sheets commonly prescribed in national construction sites. In conclusion, this study found that bubble sheets had the effect of reducing the cost of curing materials and the fuel cost consumed by a heating apparatus, compared to the use of blue sheets.

• Bulletin of the Korean Space Science Society
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• 2008.10a
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• pp.33.1-33.1
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• 2008

As a part of the construction of Korean Space Weather Prediction Center (K-SWPC), Korea Astronomy and Space Science Institute (KASI) installed a Scintillation Monitor (SCINTMON) and an All-Sky Camera to observe upper atmospheric/ionospheric phenomena. The SCINTMON is installed in KASI building in Daejeon in cooperation with Cornell university and is monitoring the ionospheric scintillations on GPS L-band signals. All-Sky Camera is installed at Mt. Bohyun in Youngcheon in cooperation with Korea Polar Research Institute. It is used to take the photograph for upper atmospheric layer through appropriate filters with specific airglow or auroral emission wavelengths and to observe upper atmospheric disturbance, propagation of gravity wave and aurora. The integrated data from the instruments including SCINTMON and All-Sky Camera will be used for giving nowcast on the space weather and making confidential forecast based on some space weather prediction models.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.48 no.1
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• pp.82-90
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• 2012

Four different buildings having various wall construction are analyzed for the effect of wall mass on the thermal performance and inside building air and wall temperature transient and also for calculating the energy consumption load. This analytical study was motivated by the experimental work of Burch et al. An analytical solution of one-dimensional, linear, partial differential equations is obtained using the Laplace transform method, Bromwich and modified Bromwich contour method. A simple dynamic model using steady state analysis as simplified methods is developed and results of energy consumption loads are compared with results obtained using the analytical solution. Typical Meteorological Year data are processed to yield hourly average monthly values. This study is conducted using weather data from two different locations in Korea: Daegu having severe weather in summer and winter and Jeju having mild weather almost all year round. There is a significant wall mass effect on the thermal performance of a building in mild weather condition. Buildings of heavyweight construction with insulation show the highest comfort level in mild weather condition. A proportional controller provides the higher comfort level in comparison with buildings using on-off controller. The steady state analysis gives an accurate estimate of energy load for all types of construction. Finally, it appears that both mass and wall insulation are important factors in the thermal performance of buildings, but their relative merits should be decided in each building by a strict analysis of the building layout, weather conditions and site condition.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.05a
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• pp.57-60
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• 2008

This study investigated the results of insulation heat curing method using double layer bubble sheet in slab concrete and mass concrete in cold weather environment. First of all, when double bubble sheets are applied, it was shown that slab concrete was protected from early freezing by remaining between 6 and 15℃ even in case outside temperature drops -9℃ below zero until the 2nd day from piling, and in the case of mass concrete, with the maximum temperature difference between the center and surface less than 4℃, crack occurrence index was close to 2 and no hydration heat crack occurred by internal constraint. The insulation heat preservation curing method using the double bubble sheet applied in this field prevented early freezing owing to stable curing temperature management, deterring concrete strength development delay at low temperature, and obtained the needed strength. Also, it was proven that the method is highly effective and economic for cold weather concrete quality maintenance through curing cost reduction like construction period shortening and labor cost reduction, etc by reducing the process of temporary equipment installation and disassembling.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05a
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• pp.83-85
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• 2011

This study investigated the results of insulation heat curing method using double layer bubble sheet in concrete in cold weather environment. First of all, when double bubble sheets are applied, it was shown that concrete was protected from early freezing by remaining between 7℃ and 3℃ even in case outside temperature drops -7℃ below zero until the 3d day from piling. The insulation heat preservation curing method using the double bubble sheet applied in this field prevented early freezing owing to stable curing temperature management, deterring concrete strength development delay at low temperature, and obtained the needed strength. Also, it was proven that the method is highly effective and economic for cold weather concrete quality maintenance through curing cost reduction like construction period shortening and labor cost reduction, etc by reducing the process of temporary equipment installation and disassembling.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.05b
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• pp.25-28
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• 2009

This study investigated the results of insulation heat curing method using double layer bubble sheet in slab concrete in cold weather environment. First of all, when double bubble sheets are applied, it was shown that slab concrete was protected from early freezing by remaining between 5 and $l0^{\circ}C$ even in case outside temperature drops $-11^{\circ}C$ below zero until the 4nd day from piling. The insulation heat preservation curing method using the double bubble sheet applied in this field prevented early freezing owing to stable curing temperature management, deterring concrete strength development delay at low temperature, and obtained the needed strength. Also, it was proven that the method is highly effective and economic for cold weather concrete quality maintenance through curing cost reduction like construction period shortening and labor cost reduction, etc by reducing the process of temporary equipment installation and disassembling.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2006.11a
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• pp.29-32
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• 2006

Experimental test results of field construction, Cheongju University Educational Liberal Art Building, applying the insulating curing method on slab concrete showed that the quality of concrete in fresh and hardened state satisfied all target values. Temperature history of slab concrete in A and B area secured more than $7.8{\sim}9.2^{\circ}C$ higher than outside atmosphere. After completing certain curing period of time on the surface of the structure, crack occurrence was not found. It is concluded that the preventing vaporization of moisture by the insulating curing method reduces plastic and drying shrinkage as welt as improves durability.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2010.05a
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• pp.71-72
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• 2010

The study is compared temperature history and strength of concrete followed by covering method of insulation curing of cold weather concrete with double bubble sheet. The results were as follows. First of all, in temperature history of concrete, the internal temperature of concrete fell down to $0^{\circ}C$ before/after 60 hours, having nothing to do with covering method. The study could see that, when sheet was isolated, it fell down to low temperature quickly in early curing. When the study measured compressive strength of core specimen, there were no large differences among placing methods. However, compressive strength fell down in all ages when sheet was isolated.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.88-89
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• 2015

In cold weather, the speed of concrete strength development is slow. As a result, construction speed becomes slow and it is problem for all construction site to solve this. So in this study, to shorten removing frame time after placing concrete, mix proportion using early-strength-binder(ESB) and curing method such as using heat line in concrete was considered. At first, concrete mix proportion was examined at -5℃ temperature between ordinary portland cement(OPC) and ESB. And second step, concrete, using mix proportion with OPC, was examined according to curing method(: 1) heat line used and 2) no heat line) and kinds of form (: 1) Deck slab, 2) Half PC slab and 3) SOG slab). All cases are same condition: slab thickness is 1,500mm, double-bubble sheet is used as a curing sheet after placing concrete. After the test, OPC is enough to get strength compared to ESB in special condition and 48~60 hours is needed according to form condition.