• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.269-270
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• 2018

Urea is liquefied when it is dissolved in water and has the effect of increasing water. It is known that when using urea, it is generally possible to reduce the number of design units in order to ensure the same flow-ability, because the effect of increasing the water when using urea in the manufacturing of concrete is known. In this study, the change of basic properties of concrete when using urea was investigated in concrete production, and the effect of reducing the unit yield was confirmed.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.136-137
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• 2018

The properties of concrete produced by ready mixed concrete company in Busan were measured. Because the concrete was mixed with blast furnace slag and fly ash etc., the compressive, tensile strength and chloride ion diffusion coefficient were lower than OPC concrete even though the specified concrete strength was same. If the durability about salt attack were satisfied, the concrete of lower specified concrete strength would be adopted to concrete mixing design. FEM analysis was carried out to predict the life time expectancy.

• Magazine of the Korean Society of Agricultural Engineers
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• v.41 no.6
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• pp.75-81
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• 1999

This study is performed to evaluate theproperties of concrete using industrial wastes such as fly ash, zeolite powder and blast furnace slag powder. Seven types of concrete mixtures are made in this study. Water0reducing admixture and air entaining agent are used for all mixtures. Test results, the hydration evolution amounts are decreased by 2 ∼31 % than that of the normal portland cement and air contents of concrete are decreased by 1 ∼15% and compressive strengths are increased by 2∼10% at the curing age 28 days than that of the normal portland cement concrete. Accordingly, concrete using industrial wastes will greatly improve the properties of concrete.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.78-79
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• 2015

For estimating compressive strength of concrete, non-destructive test has conducted generally. It used experimental equation to calculate compressive strength from construction. This study investigated experiment to apply non-destructive test, based on fresh property, compressive strength and ultrasonic pulse velocity of high performance concrete. And it conducted to compare various proposed equation.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.34-35
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• 2014

In this study, the effects of high temperatures on the compressive strength and elastic modulus of HPC with pp and jute fiber (jute fiber addition ratio: 0.075 vol%; length: 12 mm; PP fiber addition ratio: 0.075 vol%; length: 12 mm) were experimentally investigated. The work was intended to clarify the influence of elevated temperatures ranging from 20 to 500℃ on the material mechanical properties of HPC at 80 MPa.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.74-75
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• 2013

The paper study on the mechanical properties of reactive powder concrete using copper slag. A change in the replacement ratio s of copper slag was measured compressive strength and slump flow. As a results, slump flow using copper slag tend to increase slump flow with replacement ratio. As the concrete with a replacement ratio of copper slag up to 30% was found to have a compressive strength superior to that of plain.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.54-55
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• 2013

Recently, The economic growth has increased carbon dioxide emissions. so, It is caused by social problem to environmental damage and human health due to global warming. Accordingly, The method solution is to the amount of cement and to use industrial by-product such as Blast furnace slag, Fly Ash, and Red-mud. Thus, The purpose of this study is to analyze the physical property of concrete with red-mud. So, this study carries out the basic performance test of concrete such as, air content, slump, and compressive strength. In this work test is conducted according to sequence of materials using concrete twin mixer.

• Journal of the Korea institute for structural maintenance and inspection
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• v.3 no.1
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• pp.163-169
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• 1999

The object of this study is to compare properties of massive fly-ash concrete with plain concrete. Two concrete mixtures comprising two batch each $1.0m^3$ in volume, were made from ready mixed concrete batch plant. The water-to-cementitious materials ratio was kept constant at 51.4%. Therefore, massive concrete specimen($W800{\times}D800{\times}H800mm$) was cast from ready mixed concrete to analyze history of temperature and core strength properties. Bleeding, time of slump loss and time of setting of the fresh concrete were measured. In order to estimate the properties of massive fly-ash concrete in hardened concrete, non-destructive tests such as rebound hardness, ultrasonic pulse velocity and maturity were performed and analyzed.

• Journal of the Korea institute for structural maintenance and inspection
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• v.1 no.1
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• pp.97-105
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• 1997

The major object of this study is to analyze and investigate experimentally the experimenal equation for the estimate of compressive strength of concrete. The results are as follows. The relation between maturity scaled logarithm and compressive strength of concrete can be expressed in liner equation which show an good correlation. And combined method using rebound number, pulse velocity and water cement ratio also show an excellent correlation. The equation by combined method is same as the conclusions.

• Journal of the Korea Institute of Building Construction
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• v.3 no.4
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• pp.119-122
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• 2003

Most concrete is recently made of an aggregate which is properly absorbed, and carried in it in order to do capability at every fields. We have been close to demand new capability of high flowing and enduring for specific concretes. That is difficult to cope with claiming the efficiency on deterioration from lack of a high quality aggregate Therefore, For solving the problems we apply to a packing method for using dried materials. That is to say it is a kind of making into an instant. In this study, There is a purpose to present fundamental data, comparing and analyzing a phenomenon about aggregate's absorption following the rate of adding water, for using existing materials.