• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.273-276
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• 2003

The non-evaporable water and calcium hydroxides were measured by TG/DTA for studying the temperature effect on hydration of concrete mixture. The experimental parameters introduced in this study were the curing temperatures, ages and W/C ratios. The mixing temperature was also controlled to improve the efficiency of experimental work. While the mixture cured at high temperature showed the large quantity of non-evaporable water and calcium hydroxides at early age, the production rate of these hydration products was decreased as increasing the curing age, and the quantity of hydration product became smaller than that of the corresponding mixture cured at lower temperature at later age.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.277-280
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• 2003

The purpose of this study is for the active use of the fly ash, which is a by-product of the combustion pulverizes coal thermal power plants, to compensate for the lack of landfill and for conservation of energy, by using fly ash as the supplementary cementitious material, and to prove its possibility as the related products of the cement. First of all, we examined strength development of Micro grinding fly ash by elevating its fineness and using $Na_{2}SO_{4}$ as an activator to elevate pozzolanic reaction of fly ash. Following fly ash replacement ratio and curing temperature we hope to prove its properties to suggest its possibility in the concrete and cement industry. In case of water curing, the more fineness and higher annexing of activator is, the higher strength is, and the higher curing temperature is the more pozzolanic reaction happens.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.343-344
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• 2010

This study compares the apparent activation energy(Ea) by ASTM C 1074 with that by setting time. As the result of this study, it is found that Ea by setting time was ranged from 15~21 KJ/mol. This value is smaller than that 30~50 KJ/mol by ASTM C 1074.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.445-446
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• 2010

Water existed inside of bubble sheet applied at the job site sometimes results in undesirable heat insulation capability of bubble sheet. Therefore, the objective of this paper is to examine experimentally the effect of water presence in bubble sheet on heat insulation capability and strength of the concrete cured with double bubble sheet.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.157-165
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• 1997

In this experiment, there is a purpose to analysis the relationship of feature of compressive strength after fixing of remarkable element under the condition of initial curing temperature. According to this experiment, we get to the fallow result. In case of highest curing temperature, 3-day-strength become high but last revelation of strength become low among the condition of initial curing temperature, the highest curing temperature have an effect on revelation of strength by the application of cumulative temperature, we can get the shape of revelation of strength.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.799-804
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• 2003

The purpose of this study was to investigate the effects of re-vibration and curing temperature onto the physical properties of latex-modified concrete with ordinary cement and rapid-setting cement, and thus to provide a guide line of re-vibration and curing conditions for good quality controls. The main experimental variables included two cement types(ordinary portland cement, rapid-setting cement), curing Temperature($10^{\circ}C$, $20^{\circ}C$, $30^{\circ}C$), re-vibration methods(continued, intermittent), and re-vibration times(initial setting, one day after mixing). The experimental results showed that the re-vibration affected little to the mechanical properties of LMC and RSLMC, while, the curing temperature a quite some. The early strength development was the highest at $20^{\circ}C$ curing temperature, and decreased at higher temperature. The permeability of concrete generally decreased with curing time. The rapid chloride permeability was a function of time and temperature. The chloride permeability of RSLMC was so small and negligible.

• Journal of the Korea Concrete Institute
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• v.12 no.6
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• pp.35-42
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• 2000

In paper I, the relationships between compressive strength and splitting tensile strength or modulus of elasticity were proposed. In this paper, new prediction model is investigated from estimating splitting tensile strength and modulus of elasticity with curing temperature and aging without compressive strength. New prediction model is based on the model which was proposed to predict compressive strength, and splitting tensile strength and modulus of elasticity calculated by this model are compared with experimental values of paper I. To evaluate in-situ applicability of the model, strength and modulus of elasticity tested with variable temperatures are estimated by the prediction model. The prediction model reasonably estimates the strength and the modulus of elasticity of type I and V cement concretes tested in paper I and experimental results with variable temperature tested in this paper.

• Proceedings of the Korean Institute of Building Construction Conference
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• v.y2004m10
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• pp.11-14
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• 2004

The object of this study is vibrating compaction and curing method in the production process of Design concrete for precast concrete(Design-PC) product. From change of vibrating compaction time and pre-curing time. curing temperature which would be factors of product quality in Design-PC concrete production. and research of optimized steam curing condition from relations between curing condition and strength development. basic data of vibrating compaction time and concrete steam curing method for Design-PC will be presented.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.05a
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• pp.105-107
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• 2012

This study was conducted to investigate the strength development of fly ash concrete using the strength development estimation for the ready mixed concrete for construction of nuclear reactors. The findings are as follows. First, the higher the curing temperature becomes, the shorter the setting time becomes. In addition, the compressive strength also increased as the curing temperature gets higher. The apparent activation energy derived from ASTM C 1074 showed 34.75 KJ/mol. The results of concrete strength estimation confirmed that Gompertz model formula has good accuracy.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.117-124
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• 1997

In this study, mechanical properties of type V cement concrete with different curing temperature were investigated. The tests for mechancial properties, i.e., compressive strength and modulus of elasticity, were carried out on two kinds of type V cement concrete mixes. concrete cylinders cured at 10, 23, 35 and 50℃ were tested at 1, 3, 7 and 8 days. The 'rate constant model' was used to described the combined effects of time and temperature on compressive strength development. Test results show that concrete subjected to high temperature at early age attains greater strength than concrete to low temperature but eventually attains lower later-age strength than that. With type V cement concrete, the linear and Arrhenius rate constant models both accurately describe the development of relative strength as afunction of the equivalent age.