• 레미콘
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• no.9 s.29
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• pp.40-54
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• 1991

• Magazine of the Korea Concrete Institute
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• v.8 no.2
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• pp.20-31
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• 1996

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.115-116
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• 2015

Since concrete has evolved to the development of the quality and performance there currently being used civil engineering, as the most important material in the construction sector. But the discovery of alternative building materials and indiscriminate use is negligible. So that is the situation facing the shortage of natural aggregate. Accordingly, this study reviewed the mechanical properties by replacing the aggregate through the mud flat of eco-friendly materials and analyze the usability by adding a high-performance water reducer for promoting workability.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.23-26
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• 1999

The properties of concrete can be affected by high range water reducing agent and cement. The data for compatibility and effect of fluidity is reported already according to the mixing proportion of kinds of cements and high range water reducing agents. Moreover, the international market of construction has been opened, the international standard of capability has been promoted and the international exchange of construction materials has been brisked. This study investigated fluidity properties of mortar due to kinds of cements and high range water reducing agents which are producted in different nations. Also studied were the compatibility effect of cements and high range water reducing agents.

• Cement Symposium
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• s.39
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• pp.178-183
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• 2012

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.1
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• pp.72-79
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• 2011

This study is performed to analyze the effects of CASB by applying the superplasticizer combined CASB on the ultra high strength mortar and concrete that uses different mineral admixture depending on whether the silica fume was used and the results are summarized below. From the characteristics of Fresh mortar and concrete, the fluidity was lower in B2-CASB than B2-PC from the mixing of CASB and based on the viscosity of the mortar and concrete in the binary proportion but in the ternary proportion, B3-CASB showed a larger fluidity than B3-PC because of a reduction in the restriction level due to the effects of an improvement of particle size distribution. The compression strength was higher in ternary proportion than in binary proportion and higher in CASB than in PC from the characteristics of hardening mortar and concrete and this is analyzed as a result of increased minuteness from the calcium silicate hydrates produced from the pozzolan reaction of a mineral admixture, SF, and also the charging effects of capillary pore of CASB. Overall, when using the nanomaterial, CASB in combination with a superplasticizer, the fluidity and the strength aspects of the ternary proportion of ultra high strength mortar and concrete with silica fume may be improved to a higher quality.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.7
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• pp.4644-4652
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• 2014

This study examined the effects of the cement type and sand to cement ratio on the properties of grout for offshore PSC structures. Types I and III cement were used and the sand to cement ratio was varied from 0.5 to 1.5. When type I cement was used, considerable bleeding occurred on the all S/C after 3 hours and 20 hours. When type III cement was used, bleeding was reduced but the flowability decreased. A comparison of a superplasticizer containing naphthalene with that containing polycarboxylate showed that the problem of flowability could be solved using polycarboxylate.

• Proceedings of the Korea Concrete Institute Conference
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• 1994.10a
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• pp.151-156
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• 1994

This study is to investigate the quality of superplasticizers in domestic market. Therefore, the physico-chemical characteristics, the fluidity characteristics of fresh cement paste and mortar were tested. Also fresh and hardened properties of mortars and concretes using these superplasticizers were tested. From these results, differences of quality among superplasticizers are checked clearly in low water/cement ratio. And it is concluded that several superplasticizers have better dispersion ability than others in every tests. It has known that all samples are naphtalene sulfornate formaldehede types by the UV(ultra-violet) test.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.729-732
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• 2008

Naphthalenic admixture(PNS) has been widely used as main component of AE reducing agent among superplasticizers for concrete for a long time. However its noxiousness has been appointed because of formaldehyde compound applied during in synthetic process. In this study, AE reducing agent prepared using PNS and substituted-PNS agent(ECO-AEM) without formaldehyde compound added to concrete. For these agent, the basic performance of concrete and ecological affinity properties were evaluated and compared.

• Journal of the Korea Concrete Institute
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• v.17 no.1 s.85
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• pp.77-84
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• 2005

The steel slag, a by-product which is produced by refining pig iron during the manufacture of steel, is mainly used as road materials after aging. It is necessary to age steel slag for long time in air because the reaction with water and free-CaO in steel slag could make the expansion of volume. This problem prevents steel slag from being used as aggregate for concrete. However, steel slag used in this study was controled by a air-jet method which rapidly cools substance melted at a high temperature. The rapidly-chilled method would prevent from generation of free-CaO in steel slag. This study dealt with the influence of the using rate of rapidly-chilled steel slag on flow, dosage of SP, W/C ratio, and strength of mortar by statistical experimental design. Also, the results of this experiment were approved by statistical analysis methods, such as analysis of variance and F-testing. As results of F-testing, this paper proved at $1\%$ level of significance that the more the using rate of rapidly-chilled steel slag increased, the more this affected the enhancement of flow, the decrease of dosage of SP and W/C ratio, and the development of compressive strength. Also, considering the fluidity and compressive strength of mortar, it is desirable to use $75\%$ of rapidly-chilled steel slag for river sand.