• Proceedings of the Korea Concrete Institute Conference
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• 1992.04a
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• pp.7-12
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• 1992

The aim of this study is to develop economical High-Strength and High-Quality Concrete, and to assure quality control of Concrete in the field. For this purpose, Five types of Mixing Methods are examined and the relationship between slump loss and slump recovery by transport is studied. As a result, workability and strength are dependent on the Mixing Method, although the Mixing proportions are same, Also, adding admixture in the field is proposed as an alternative to consider the relationship between slump loss and slump recovery.

• Proceedings of the Korea Concrete Institute Conference
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• 1992.04a
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• pp.29-34
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• 1992

In this experimental study, we aimed at the improvement of compressive strength of artifitial light weight aggregate concrete by using the micro powders of mudstone for concrete admixture. By it's result, there was about 10% increase of compressive strength in concrete adding the 10% amounts of powders for cement contents than that of plain concrete.

• Proceedings of the Korea Concrete Institute Conference
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• 1996.10a
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• pp.169-174
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• 1996

It have been announced that concrete subjected to freezing and thawing cause deterioration by expanded inside water and contracted at thawing. However, this study descrebe the deterioration mechanism of concrete by freezing and thawing test. Embeded strain gauges were used to measure the inside restrict strain due to the temperature differenct inside and outside the concrete test specimens. Test results showed that using the air entrained admixture and expanded poly-styrene was developed durability of concrete by decreasing inside retrict strain ratio.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10b
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• pp.951-956
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• 2000

Blast furnace slag powder(BFS) is potential hydration material, and that usage is increased the construction. But, the amount of BFS is important factor with the properties of concrete. The determinational method of slag powder experiments by salicylic acid-methyl alcohol solution method. From these results we can determine the amount of slag powder with blaine 4, 000 and 6, 000 in fresh concrete.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.04a
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• pp.124-128
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• 1997

In order tohave a betterunderstanding of thefavorable effect ofground granulated blast-furnace slag and fly ash, slump loss, temperature risingand compressive strength of concrete were investigated into diffrent conditions. When slag was mixed with ordinary portland cement as30%, slump loss gotto some 18% at 60min, maximum temperatureto some $43^{\cire}C$ at 180min, compressive strength similar to that of ordinary portland concrete at 28 days. Therefore it wasnoted thatslump loss andmaximum teaperaturerising of concrete were very reduced according to ground granulated blast-furnace slag and fly ash mixed with ordinary portland cement.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.179-180
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• 2015

Recently, admixture manufacturers have improved the performance of admixtures to solve problems caused by high viscosity of high performance admixtures, and accordingly, it is expected to affect fluidity of concrete using admixtures. Therefore, in this research, how each kind of HAE affects consistency curve of cement mortar was examined.

• Proceedings of the Korea Concrete Institute Conference
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• 1991.10a
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• pp.140-145
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• 1991

Tests were conducted to get a mix proportioning of high strength concrete between σ28 and (C/W) using low quality materials easily purchased in situ. Superplasticizer was used as a chemical admixture to compensate low slump of base concrete keeping it up about 15±2㎝. General material properties such as modulus of elasticity, poisson's ratio, unit weight and stress-strain characteristic of high strength concrete were obtained. Test results show that mix proportioning of high strength concrete proposed in this paper have reasonable validity and these can be used as a design criteria in high strength concrete construction.

• Proceedings of the Korea Concrete Institute Conference
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• 1991.10a
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• pp.21-25
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• 1991

For the purpose of improving the compressive strength of concrete, the high strength concrete which have the compressive strength about 800kg/$\textrm{cm}^2$ were made by using silica fume and high range water reducing admixture on reducing the water-cement ratio. But the facts that the slump loss of high strength concrete was high and the tensile strength and elastic modulus were not improved enough are indicated to problems which must be solved.

• Proceedings of the Korea Concrete Institute Conference
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• 1991.10a
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• pp.129-134
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• 1991

The effects of water-cement ratio, age, and admixture such as fly ash, silica fume on the bond strength between aggregate and mortar were investigated. As the result, with increasing of water-cement ratio, the bond strength was slightly decreased while the compressive strengths of mortar and concrete were seriously decreased. The rate of strength gain of bond strength was not decreased with increasing of water-cement ratio while that of compressive strength was gradually decreased.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.46-47
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• 2013

In this research, it is investigated strength development by replacement ratio of mineral admixture contents, types of superplastisizer and strength improvement material contents based on industrial byproduct to expand use of low cement concrete for typical floor.