• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.217-219
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• 2012

In this study, the experiment was conducted in the level of mortar as one of the basic studies on pre-cast concrete which acceleration curing is not done. This study has the purpose to develop the strength of mortar into 20MPa within 6 hours in the condition of room temperature using admixtures which can accelerate C3S hydration reaction. In this experiment, W/C was fixed into 20%, PCE which can stimulate C3S was used as an accelerating admixture. From the results of this experiment, maximum content of accelerating admixture was 1%. Also, as more than 20MPa was measured through 6-hour compressive strength, it can be known that strength can be developed without steam-curing.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2005.05a
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• pp.25-28
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• 2005

This study shows the early quality improvement of concrete with calcium sulfa aluminate(CSA). For the properties of slump, plain concrete incorporating BS $35\%$ and UP $15\%$ resulted in high fluidity compared with OPC without any admixture. As displacement ratio of CSA increased. the fluidity decreased. The fluidity also declined with setting time. Increase of incorporation ratio of CSA declined bleeding and accelerated setting time. Importantly, using more CSA helped to improve early compressive strength and decrease drying shrinkage. In term of water curing, drying shrinkage hardly ever occurred.

• Proceedings of the Korea Concrete Institute Conference
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• 1994.10a
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• pp.180-185
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• 1994

An experimental study was carried out for the estimate of the properties of concrete contained an antiwashout admixtures. Properties of antiwashout under water concrete clearly differed from other types of concrete. This paper reports the effects of specific types, dosage of antiwashout admixtures and superplasticizer. The test results have indicated that dosage of antiwashout admixture and superplsticizer to improve the antiwashing property, fluidity and compressive strength will be approximately 2.5kg/$\textrm{m}^3$, 8~10kg/$\textrm{m}^3$ of the weight of concrete each. When cellulous ether type antiwashout admixture is added with a napthalen sulphonate superplasticizer, resulting in reduced whole properties of antiwasout under water concrete.

• Proceedings of the Korea Concrete Institute Conference
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• 1995.04a
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• pp.94-99
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• 1995

Naphthalene sulfonated condensatd(NSF) has been widely using for the superplasticizing of ement and concrete. But NSF has a very large mobility loss with elapsed tiom. To retain mobility of NSF during a certain time, maleic anhydride and acrylic acid copolymer(MA) was polymerized and mixed with NSF in order to perpare admixture holding mobility-retention property of cement. By applying this admixture for ement paste, we examined the fluidity and mobility retention property as a function to elapsed time and measured the compressive strength of mortar with curing time. As a result, NSF containing 20wt% of MA showed very excellent fluidity and mobility-retention property. These properties were affected by the added amount of admixture and the ratio of water to cement.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.36-39
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• 2004

In this study, effects of fluosilicate salt based chemical admixture(MZ) on the watertightness and hardening properties of concrete were investigated. Mix proportions for experiment were modulated at 0.55 of water to cement ratio and addition amount of MZ to $2.0\%$ at intervals $0.5\%$. Compressive strength, porosity and microstructure of hardened concrete cured at several days were executed to evaluate watertightness and hardening properties. It is ascertained that watertightness and hardening properties of concrete could be improved by an adequate addition of fluosilicate salt based chemical admixture.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1997.05a
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• pp.70-73
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• 1997

Recycling of$\boxUl$ useful industrial waste is highly recommended by the government. Some geotechnical properties such as specific gravity, dry density, unconfined compressive strength, pH. compressibility, permeability were determined to evaluate the feasibility of waste lime use in the landfill as an admixture clay liner. Various types of environmental tests on waste lime were conducted to compare the results with the EPA requirements. Laboratory test results indicate that admixture soil(waste lime/decomposed granite soil) is a promising material its an admixture clay liner in the sanitary landfill.

• Journal of the Society of Naval Architects of Korea
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• v.40 no.1
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• pp.55-62
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• 2003

This study has investigated physical and chemical properties of FRP waste, has manufactured polymer cement mortar using a crushed waste with sand and has evaluated its capability to develop the economical waste recycling technology. The study has investigated tension strength, hardness test and impact test as physical properties and also thermogravimetric characteristics and analyzed infrared spectroscope as chemical properties. Then the study has manufactured polymer cement mortar and has analyzed how the FRP waste fine aggregate replacement ratio has an effect on compression strength. Noticing admixture can complement strength drop occurred by the FRP waste fine aggregate replacement, the study examined an optimum rate of admixture addition and its reaction through electron microscope photos.

• Journal of the Korea Concrete Institute
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• v.12 no.3
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• pp.11-19
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• 2000

It has been reported that few manufacturers of cement mortar for precast products use chemical and mineral admixture due to the absense of restrictions related to the application of admixture and the poor manufacturing facilities. Therefore, this paper is intended to contribute to the improvement of quality by investigating the properties of cement mortar for precast products using fly ash, blast furnace slag and AE water reducing agent. According to the test results. it was found that the cement mortar products using fly ash and AE water-reducing agent had better qualities than those of ordinary portland cement.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.521-524
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• 2006

In this paper, admixture factors affecting the properties of lightweight foamed concrete incorporating cement kiln dust(CKD) and fly ash(FA), respectively are discussed. Increase in CKD contents resulted in loss of fluidity and decrease in settlement of concrete noticeably. Moreover, the higher the unit weight is, the smaller the settlement depth is. The use of CKD resulted in slight decrease in compressive strength and tensile strength compared to that with other admixture. However, all mixtures met the requirement of strength prescribed in Korean Industrial Standards.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2010.05a
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• pp.63-65
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• 2010

The purpose of the study was to analyze dry shrinkage of HVFAC (high volume fly ash concrete) with admixture to improve early strength. The results were as follows. In dry shrinkage of HVFAC with admixture to improve early strength, F3 had the lowest amount of dry shrinkage. The next is in order of Plain, F3-f15 and F3-f15r5. The study used index function modelfor analysis on dry shrinkage. Coefficient of determination was more than 0.97 in all mix, which made it possible to have a good estimation.