• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.47-49
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• 2012

Under this study, the characteristics of concrete intensity condition following the curing method under the extremely low temperature environment have been contemplated, and as a result, in the event of insulation + heat cable curing, the intensity and accumulated temperature accomplishment period is required for two times of requiring initial frost damage prevention than the case of heating + heat insulation curing method due to the insufficient calories supplied in general.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.553-556
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• 2003

This study is analyzed about the factor of adhesive strength characteristics, curing time, asphalt application, test temperature which are liquid waterproofing membrane of rubber-asphalt and chloroprene-rubber type for concrete bridge deck. According to the results, curing time is shorter, adhesive strength is less in chloroprene-rubber type. And also chloroprene-rubber and rubber-asphalt type are showed high adhesive strength in low temperature.

• Computers and Concrete
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• v.6 no.6
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• pp.437-450
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• 2009

The effect of six different curing conditions on compressive strength and ultrasonic pulse velocity (UPV) of volcanic pumice concrete (VPC) and normal concrete (NC) has been studied. The curing conditions include water, air, low temperature ($4^{\circ}C$) and different elevated temperatures of up to $110^{\circ}C$. The curing age varies from 3 days to 91 days. The development in the pulse velocity and the compressive strength is found to be higher in full water curing than the other curing conditions. The reduction of pulse velocity and compressive strength is more in high temperature curing conditions and also more in VPC compared to NC. Curing conditions affect the relationship between pulse velocity and compressive strength of both VPC and NC.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.153-154
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• 2023

In this study, analyzed the difference in compressive strength of concrete under cold conditions, using the 28-day standard curing compressive strength as a reference and examining variations based on cement types and curing temperatures. The results showed that the strength difference based on curing temperatures reached up to 9MPa at 0℃. However, as the curing period progressed, the difference in strength due to curing temperature gradually diminished. These findings are anticipated to be valuable for concrete mixing and quality control in cold weather conditions.

• Journal of the Korea Institute of Building Construction
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• v.3 no.4
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• pp.87-94
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• 2003

This study is to investigate the temperature hysteresis and development of compressive strength due to the curing conditions and to evaluate the optimum curing condition of test specimens showing the same development of strength to that of real structures in cold weather. The results of temperature curve with curing conditions in mock-up tests showed the trend of decrease plain concrete with insulation form, plain concrete with heating, concrete with accelerator for freeze protection, and control concrete in turn. The strength development of plain concrete of inside and outside of shelter showed the very slow strength gains due to early freezing, but that of concrete with accelerator for freeze protection showed the gradual increase of strength with time. From this, it is clear that accelerator for freeze protection has the effects of refusing the freezing temperature and accelerating the hardening under low temperature. Strength test results of small specimens embedded in members and located in insulation boxes at the site are similar to that of cores drilled from the members at the same ages, thus it is clear that these curing methods are effective for evaluating in-place concrete strength

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.641-644
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• 2008

The strength of concrete is developed by cement hydration reaction influenced by the circumferential temperatures. In this study, therefore, the experiments are conducted and evaluated about the characteristics as changes of early concrete placing temperature and curing temperature to understand the effects of the temperature which influences concrete properties. The results of the experiments changing the early concrete placing temperature in 5$^{\circ}C$ and 10$^{\circ}C$ are followed. In case of conducting standard concrete curing, early compressive strength development rate of the concrete which had low placing temperature was low, but it was shown that early compressive strength development rate was not affected by low placing temperature in age 28 days of concrete. In case of conducting outdoor curing in winter, early compressive strength development rate of the concrete which had high placing temperature was high in all test specimens. As a results, early compressive strength development of concrete was influenced by temperature of early concrete, but after aging 28 days of concrete, it was influenced by curing temperature rather than temperature of early concrete.

• Journal of the Korea institute for structural maintenance and inspection
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• v.5 no.2
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• pp.191-197
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• 2001

In this study, the admixtures for agents for enduring cold weather used widely are collected and applied to cement mortar to analyze the strength development due to variation of curing temperature at early age. The test results show that anti-freezing admixture have some problems due to high chloride content, which may cause the corrosion of reinforcement embedded in concrete. However, the mortar applied by accelerator and another kind of agent for enduring cold weather produced by S company lead to delay of strength development in low temperature. Also, it is clarified that there are no significant problems for cement mortar in strength development due to low temperature if a suitable kind of agent enduring cold weather is used and cement mortar is cured for more than $7.5^{\circ}D.D$ at early age.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.337-342
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• 1999

The Purpose of this study is to evaluate the strength characteristics of polyurethane(PUR) mortar cured under low temperature condition. PUR mortars are prepared with various catalyst content, methylene chloride(MC) content as a viscosity reducing agent, and curing age at low temperature condition of $0^{\circ}C$, -5$^{\circ}C$ and -1$0^{\circ}C$, tested for working life, compressive and flexural strengths. From the test results, the catalyst and MC contents affect the degree of hardening and blowing of PUR mortar. Strengths increase with an increasing catalyst content at low temperature. Flexural and compressive strength of PUR mortar are about 177kgf/$\textrm{cm}^2$ and 490kgf/$\textrm{cm}^2$ respectively at curing temperature of -1$0^{\circ}C$ with catalyst content of 0.4%. Therefore, it is apparent that this PUR mortars have a sufficient strengths for repair of concrete structures.

• 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.

• Journal of the Korean Society of Tobacco Science
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• v.20 no.2
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• pp.160-165
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• 1998

The Joint curing barns for flue-cured tobacco is a favorite with the tobacco farmers in Korea. However, most of farmer utilizing the joint curing barns indicated many problems such as high temperature and noise in the working room and a dry of cured leaves in the storage room. A structure of Joint curing barns has been modified to meet the needs of tobacco farmers. Compared with the unimproved joint curing barns, the improved one showed that the noise of workshop decreased about 7.7～10.8db, the amount of $CO_2$ decreased 40～50ppm in a working room and 80～100ppm in a machine room. Ammonia gas decreased 0.29mg/㎥ and the temperature of a working room dropped about 2.1～3.5$^{\circ}C$. The amount of air flow in a working room increased 23.2% at a site being 2m away from the entrance and 30.8% at a center. The inner temperature of the improved storage room showed that maximum temperature dropped about 3$^{\circ}C$, minimum temperature was high about 2$^{\circ}C$. The highest relative humidity was low 6%, the lowest one increased high about 10% when compared with the unimproved joint curing barns.