• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.919-922
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• 2008

This paper reports the physical and shrinkage properties of concrete using expansive additive(E) and three shrinkage reducing admixtures(SRA1, 2, 3) in order to reduce shrinkage of concrete. For the properties of fresh concrete, the use of SRA1, 2, 3 results in a increase in fluidity and decrease in the dosage of super plasticizer as much as 0.05$\sim$0.1%. And For the properties of hardened concrete, the use of SRA1, 2, 3 results in a decrease in compressive, tensile and flexural strength slightly. For drying shrinkage properties, the use of SRA3 is the most effective for reduction of shrinkage, and the next best way to reduce shrinkage is combination with expansive additive(E) and shrinkage reducing admixture(SRA) or the using of expansive additive(E).

• Korean Journal of Food Science and Technology
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• v.29 no.6
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• pp.1131-1137
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• 1997

The production rates of leavening gases and textures of cookies were investigated with various chemical leavening agents(baking powders). The chemical leavening agents could be divided into three group of a fast-acting group such as potassium bicarbonate, tartaric acid, aluminium ammonium sulfate, and fumaric acid, a slow-acting group such as ammonium bicarbonate, sodium bicarbonate, $glucono-{\delta}-lactone$, and ammonium chloride. and a double-acting group such as anhydro monocalcium phosphate, disodium dihydrogenpyrophosphate, and aluminium potassium sulfate according to the different production rate of gases. The leavening rate of ammonium bicarbonate, which was the highest of all leavening agents used in this experiment, was 131.25%. But its after-taste in a cookie was not good due to the residual ammonia. $Glucono-{\delta}-lactone$ only had no after-taste. The higher leavening rate, the more peaks in texture profile graph. Ammonium bicarbonate showed the most peaks in this experiment. It was found that the number of peak had correlation with brittleness of cookies $(r^2=0.8176)$ and brittleness of cookies was different as to various chemical leavening agents.

• Korean Journal of Agricultural Science
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• v.24 no.2
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• pp.194-206
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• 1997

This paper was performed to evaluate the properties of no-coarse lightweight concrete using perlite and expanded polystyrene bead on fine aggregate. The results were shown that w/c and unit weight was affected by absorption ratio and unit weight of using aggregate itself. The compressive strength of no-coarse lightweight concrete was showed $187kgf/cm^2$ by using natural sand, $170kgf/cm^2$ by using perlite. Tensile and bending strength were showed the same tendency of compressive strength, but when expanded polystyrene bead concrete dose not have strength nearly. The pulse velocity and static modulus of elasticity of no-coarse lightweight concrete were smaller than that of normal cement concrete. And stress-strain curves were shown that was increased with increase of stress, and when the stress-strain curve using expanded polystyrene bead was repeated at short intervals increase and decrease irregularly.

• Cement Symposium
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• no.30
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• pp.80-88
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• 2003

• Magazine of the Korea Concrete Institute
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• v.7 no.5
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• pp.106-110
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• 1995

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2013.11a
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• pp.221-222
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• 2013

다양한 첨가제가 들어가는 고분자 화합물(compound)의 제조에 있어 난연 발포 보조제인 팽창흑연(Expandable Graphite, EGP)은 흡유가가 낮기 때문에 비교적 많은 양을 첨가해도 혼합(Mixing)이 잘 되는 것으로 알려져 있다. 본 논문에서는 대표적인 인계 난연제 APP(Ammonium Polyphosphate)를 사용한 난연 EPDM(Ethylene Propylene Diene Monomer) 폼에 팽창흑연 첨가량을 증가시키면서 산소 지수와 발열량을 통해 난연 성능의 변화를 분석하였다. 산소지수는 ISO 4589-2 상온 산소지수 방법을, 발열량 평가는 ISO 5660-1 콘 칼로리미터를 활용하였다.

• Polymer(Korea)
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• v.31 no.2
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• pp.160-167
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• 2007

This paper proposes a model for the solutions predicting the coefficient of thermal expansion of composites including fiber-like shaped$(a_1>a_2=a_3)$ and disk-like shaped$(a_1=a_2>a_3)$ inclusions like two dimensional geometries, which was analyzed by one axis and a single aspect ratio, $(\rho_\alpha=a_1/a_3)$. The analysis follows the procedure developed for elastic moduli by using the Lee and Paul's approach. The effects of the aspect ratio on the coefficient of thermal expansion of composites containing aligned isotropic inclusions are examined. This model should be limited to analyze the composites with unidirectionally aligned inclusions and with complete binding to each other of both matrix and inclusions having homogeneous properties. The longitudinal coefficients of thermal expansion $\alpha_{11}$ decrease and approach the coefficient of thermal expansion of filler, as the aspect ratios increase. However, the transverse coefficients of thermal expansion $\alpha_{33}$ increase or decrease with the aspect ratios.

• Journal of the Korea Concrete Institute
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• v.16 no.5 s.83
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• pp.605-612
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• 2004

This study investigated the fundamental properties and shrinkage properties of high performance concrete with water/binder ratio of 0, 30 and with combination of expansive additive and shrinkage reducing agent. According to the results, the fluidity of high performance concrete showed lower the using method in combination with expansive additive and shrinkage reducing agent than the separately using method of that, so the amount of superplasticizer increased when the adding ratio of expansive additive and shrinkage reducing agent increased. However the air content of concrete increased when used in combination with expansive additive and shrinkage reducing agent, so the amount of AR agent decreased. The compressive strength showed the highest at $5\%$ of expansive additive, and decreased with an increase of the amount of shrinkage reducing agent. Furthermore, in order to reduce the shrinkage of high performance concrete, it was found that the using method in combination with expansive additive and shrinkage reducing agent was more effective than separately using method of that. Therefore, it analyzed that the combination of expansive additive of $5\%$ and shrinkage reduction agent of $1\%$ was the most suitable mixture, considering to the fluidity, strength and shrinkage under the condition of this experiment.

• Journal of the Society of Disaster Information
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• v.13 no.1
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• pp.43-50
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• 2017

In this study, to investigate the strength enhancement and stress transfer effect of the inflatable chemicals used in the recovery of soft ground or partial settlement, the dilatant solution was prepared and classified by measuring the density and the earth pressure in the sand ground. The inflation reinforcing agent was prepared by injecting into a separate impervious vacuum sheet by dividing into a relatively high expansion group and a low expansion group, and a cementation experiment was performed in the lower part of the homogeneously formed model ground. As a result, reinforcing effect was shown up to about 15cm above the expansion reinforcement, and the soil pressure showed a compaction tendency similar to the concentrated load of $1.150{\sim}11.298t/m^2$.

• Magazine of the Korea Concrete Institute
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• v.8 no.2
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• pp.32-40
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• 1996