• Magazine of the Korea Concrete Institute
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• v.7 no.6
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• pp.176-185
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• 1995

The heat generation of hydration of cement causes the internal temperature rise and volum& change at early age, particularly in massive concrete structures. As the results of the temperature rise and external restraint conditions, the thermal stress may induce cracks in concrete. Therefore, various techniques of the thermal stress control of the mass concrete have been wid'dy used. One of them is pipecooling which reduces the temperature of concrete with flowing water. The objective of this paper' is to develop a finite element program which is capable of simulating the temperature history considering pipe-cooling effect. The numerical results in this study are in good agreement with experimental data measured in the footing(l1 x22m). Therefore, this study may provide available method to predict the hydration temperature of concrete with pip:-cooling.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.259-260
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• 2010

This study is to investigate each mix property and physical properties and reduction properties of heat of hydration as basic experiment of reviewing the applicability of low calorific concrete.

• Magazine of the Korea Concrete Institute
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• v.10 no.6
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• pp.281-289
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• 1998

This study has been performed to test the flowability and filling ability of high flowing concrete as well as distribution of aggregate and pore of core specimen, heat of hydration, compressive strength and core strength of concrete. In addition, the resistance to chloride ion penetration and chemical solutionof concrete was tested in order to evaluate the resistance to sea water of concrete and its application of high flowing concrete using blended low heat cement in the field of Seohae Grand Bridge. The properties of high flowing concrete with blended low heat cement were compared with ordinary 25-240-15 concrete using Type V cement. As the results of this study, the flowability and filling ability of high flowing concrete with blended low heat cement is satisfied without vibration. Though the cement content of high flowing concrete with blended low heat cement was 400kg/m$^2$, the rising temperature of it was relatively lower than that of the ordinary 25-240-15 concrete with Type V cement. Also, the compressive of high flowing concrete with blended low heat cement is similar to that of the ordinary 25-240-15 concrete with Type V cement.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.359-360
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• 2009

This Study is performed Mock-up test accounting for height of placement to review behavior of mass concrete according to kinds of cement & form. First, we measured hydration heat and show a different hydration heat generation characteristics as compared with each other. And we measured mortar outflow, the strength of concrete core and standard specimens, concrete's ability to resist chloride ion penetration in order to durability estimation of concrete. This study was aims to improve quality of mass concrete under marine environment.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2005.05a
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• pp.21-24
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• 2005

In this paper, field application of mass concrete using setting time difference of super retarding agent is reported to reduce hydration heat of concrete placed at newly constructed apartment house in Daejeon. Horizontal placing lift is applied. According to test results,: slump and air content meets the requirement of target values. For compressive strength, it exceeds the nominal strength ordered by the costumer. For temperature history, maximum temperature of center at top section shows $25.6^{\circ}C$, and at bottom section, $35.4^{\circ}C$. According to naked eye's investigation, no hydration heat crack is observed at the surface of concrete.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.6
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• pp.164-172
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• 2008

The heat of hydration for early aged mass concrete induces high temperature with the hydration. Control of the temperature difference across a section is an effective strategy to minimize the hydration heat induced cracks for the structures where internal restraint is dominant. The current prevention methods for hydration cracking show some limitations for the control of thermal gradients, and these limitations could make micro and macro cracks in surface and core of concrete. Especially cooling methods can decrease the increasing hydration temperature, but it can not prevent the problem while decreasing temperature. Consequently heating pipes are added simultaneously with the cooling pipes in order to control the temperature gradients between core and surface of the concrete, followed by the finite element analysis (FEA). Based on the FEA, the proposed method using cooling pipe and heating pipes together has been found to be an effective alternative in thermal gradient control, in terms of controlling temperature induced cracks significantly.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.657-660
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• 2008

In this study, quantitative analysis on effect of hydration heat and autogenous shrinkage of concrete using BFS was studied. Especially, it analyze section data statistically which hydration heat and autogenous shrinkage rise, and it appeared the correlation of hydration heat and autogenous shrinkage as well as quantitative coefficients of the main properties. As a result, the section which hydration heat and autogenous shrinkage of BFS-50 rise rapidly is delayed than OPC, but the slope of hydration heat and autogenous shrinkage in that section appeared similar shape in each mixing. Finally it will be possible to control the amount of autogenous shrinkage because hydration heating velocity and autogenous shrinking velocity are decreased by using BFS.

• Journal of the Korea Institute of Building Construction
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• v.2 no.2
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• pp.145-150
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• 2002

The hydration of cement paste occurs when the cement is miked with water. During the hydration, hydration heat causes the thermal stress depending on the site of concrete and the cement content. Especially in the high-strength concrete, we must give care to the concrete due to its large cement content. In this study conduction calorimeter and concrete insulation hydration heat meter were used to investigation the hydration heat characteristics of cement and concrete. To reduce hydration heat of high-strength concrete, several types of replacement of fly-ash and blast-furnace slag powder were used in this experiment. As a result of this study, it was found that hydration heat of high-strength concrete was reduced by replacement of fly-ash and blast-furnace slag powder. In case of high-strength concrete using blast-furnace slag powder, the max-heat arrival time was delayed but an effect of heat reduction was lower than a case of high-strength concrete using fly-ash, because it was considered that the heat-dependence property of blast-furnace slag powder was higher than that of fly-ash.

• Journal of the Korean Recycled Construction Resources Institute
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• v.1 no.3
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• pp.240-245
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• 2013

The optimum binder ratio of the low heat mass concrete for LNG tank was evaluated in the present study. Three types of binder such as OPC I, ground granulated blast-furnace slag powder were mixed and were used. Also fine particle cement and activator were used to raise an early age strength development and ground limestone was used to reduce the cost. As a result of the study, mix ratio II (30:30:40) was suitable for Bottom Center and mix ratio III(40:30:30) was suitable for Roof based on compressive strength and semi-adiabatic temperature.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.1
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• pp.1-7
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• 2020

GGBFS(Ground Granulated Blast Furnace Slag) is one of the most actively used mineral admixtures with excellent long-aged strength and chloride diffusion resistance. Unlike Standard covering GGBFS in Japan and the U.K., the domestic standard for GGBFS does not contain low fineness of GGBFS under 4000 grade. In this paper, several basic tests are carried out for the concrete with 3,000 grade GGBFS concrete and ternary blended concrete for reducing hydration heat by mixing 4,000 grade GGBFS and fly ash, such as fresh concrete properties, compressive strength, and shrinkage properties. The air content and slump between the ternary blended concrete and the concrete with low-fineness GGBFS showed the similar level, and the results of difference in setting time from them were less than 20 minutes, showing no significant difference. In the evaluation of compressive strength and shrinkage characteristics, the ternary blended concrete showed lower long-aged strength and higher shrinkage than the low-fineness GGBFS concrete.