• Proceedings of the Korea Concrete Institute Conference
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• 1996.04a
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• pp.36-41
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• 1996

The selection of Cement types is greatly dependent on the structural requirement and consturction location associated with control of hydration heat, acquisition of early strength, existence of sulfate attacks and so on. Based on this, this study adresses the comparison of physical properties of concrete according to the use of different cement types. As a result of testing with OPC, blast furnace slag and low heat cement, it is found that concrete made with low heat cement is much better in term of hydration heat and permeability. It is also recommended to select a preper cement type depending on structural characteristics.

• Proceedings of the Korea Concrete Institute Conference
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• 1995.10a
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• pp.329-333
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• 1995

The usual methods for the temperature control of mass-concrete structures include the use of low-heat cement, pre-cooling, or pipe-cooling. In order to control the heat of hydration of mass-concrete structures such as massive pier or anchor block, and mat foundation, the pipe cooling method is widely acceptable for pratical use. In this paper, method of analysis using the Finite Element Method was applied to analyze the heat exchange on the field of three dimensional thermal conduction. The result of analysis Well agreed with experimentally measurement data by "KUMATANI". The method of this analysis will be used widely to control the heat of hydration by the pipe cooling in mass-concrete.-concrete.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.182-183
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• 2021

In this study, This is the result of thermal characteristics analysis to suggest an efficient method of using coal gasification slag(CGS) of byproduct from integrated gasification combined cycle(IGCC). In Specific Heat characteristics, CGS and CS showed similar values. Isothermal Conduction Calorimetry showed that the hydration reaction of cement was retarded when CGS was used. Therefore, it is expected that CGS will be used as an efficient alternative to reducing the hydration heat of mass concrete as a functional aggregate combination.

• Computers and Concrete
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• v.16 no.3
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• pp.487-502
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• 2015

This study investigated particle expansion in basic oxygen furnace slag (BOF) and desulfurization slag (DSS) after heat curing by using the volume method. Concrete hydration was accelerated by heat curing. The compressive strength, ultrasonic pulse velocity, and resistivity of the concrete were analyzed. Maximum expansion occurred in the BOF and DSS samples containing 0.30-0.60 mm and 0.60-1.18 mm particles, respectively. Deterioration was more severe in the BOF samples. In the slag aggregates for the complete replacement of fine aggregate, severe fractures occurred in both the BOF and DSS samples. Scanning electron microscopy revealed excess CH after curing, which caused peripheral hydration products to become extruded, resulting in fracture.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.175-176
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• 2020

This study aims to develop the hydration heat reducing material (powder type) to lower the heat of hydration of mass members in the extremely hot weather condition. In this study, we applied the developed material to the concrete that used two kinds of binders with cement and evaluate the concrete properties with it.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.297-302
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• 2001

SRC pier at KTE 6-1 construction area is a very important structure. Precise control of quality is needed. This pier has 3.50m$\times$3.73m section and 38.20m length. So this structure must be treated as mass concrete and thermal crack caused by hydration heat should be controled. In this project belite cement concrete is used to control the thermal crack. As a result of adapting belite cement concrete perfect control is achieved. Finally, hydration heat FEM analysis of horizontal element is executed for Ordinary Portland Cement concrete and belite cement concrete. In comparison of two results, it is confirmed that using low heat portland cement concrete is necessary.

• Journal of the Korean Geotechnical Society
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• v.20 no.9
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• pp.25-32
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• 2004

Some amount of cements can be added into the soil with high water content to improve the engineering properties. In such a case, it is difficult to predict and figure out the phase changes of the soil-cement mixture which is closely associated with workability of the soil-cement mixture. Changes in heat of hydration and hardness of the cement pastes are known to provide the useful information about the phase changes of the soil-cement mixtures. In this study, heat of hydration and cone penetration depth were measured from the specimens of cement paste and 3 soil-cement mixtures. From the experimental results, it was found that the phase changes of the soil-cement mixtures are the same as those of cement paste, and that shear strength of the mixtures abruptly increases when the heat of hydration is minimum. Initial setting time of the mixtures coincides with the state when fall cone penetration depth was 1.0 mm and it is defined as plastic limit of the mixtures. Initial setting time of the mixtures is retarded as soil/cement ratio is increased. Measurements of heat of hydration and fall cone apparatus could be the useful tools to predict the phase changes of tile soil-cement mixtures.

• Journal of the Korean Chemical Society
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• v.23 no.6
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• pp.374-384
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• 1979

Hydration scheme and hydration energy are determined in ${\alpha}$ cage of zeolite NaA. The selectivity between Na(1) and Na(2) is determined from energy calculation. The waters in ${\alpha}$ cage form a distorted dodecahedral cage. The average binding energies of water(1), water(2) and water(3) are -29.847, -25.344 and -15.888 kcal/mole respectively. The positions of oxygens of hydrated waters are in good agreement with the X-ray data. The heat of immersion curve is also obtained. This result is in good agreement with the differential heat of sorption curve obtained from differential thermal analysis. It is concluded that theoretical method provides considerable uses in the determination and understanding of the hydration and interaction energy of zeolites sorbate binding.

• Korean Journal of Materials Research
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• v.12 no.7
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• pp.540-544
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• 2002

Hydration treatments were performed on the pure aluminum substrate at $100^{\circ}C$ followed by anodizing and heat treatments on the layers. The transformation behaviors of the oxide layers according to the hydration treatment were studied using TEM, XRD, RBS etc. Above $90^{\circ}C$ the hydrous oxide film could be formed, which were turned out to be hydrous oxides(AlOOH $nH_2$O). The anodization on the hydrous oxide film was more effective for the transition of amorphous anodic oxides to the crystalline $\Upsilon-Al_2$ $O_3$ comparing with the case for anodizing on the aluminum substrate without hydration treatment And additional heat treatments were also helpful for the acceleration of the transformation of the hydrous oxide to $\Upsilon-Al_2$ $O_3$. During the heat treatment the interface between $\Upsilon-Al_2$ $O_3$and the hydrous oxide layers migrated to the outer side of hydrous layer.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.57-60
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• 1997

The properties of Low-heat cement are especially in lower heat of hydration than that of other types of cement. In other respect, Low-heat concrete is more advantageous than OPC concrete in chemical resistance, long term age compressive strength, slump loss and resistance to seawater. This paper deals with 28 days age compressive strength and slump loss by elapsed time of mortar and concrete that made with Low-heat cement and 3 types of other cement.