• Proceedings of the Korea Concrete Institute Conference
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• 1998.04a
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• pp.171-176
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• 1998

Recently, the Belite cement having the high fluidity, high strength, and low heat properties, was developed, and is being promoted the efforts for application on the real structures. Accordingly, for the purpose of practical use of high strength concrete using the Belite cement, was carried out the performance evaluation experiments about the structural members(column, beam, column-beam joint, steel bond strength etc.). Specimens were made in three types of concrete(Belite:350, 600kg/$\textrm{cm}^2$, OPC:350kg/$\textrm{cm}^2$) by taking into account the key parameters. In this paper, were summarized the comparative experimental results on the material properties and structural performance of Belite concrete.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04a
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• pp.255-260
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• 1998

As a part of the study on the development of augered pile method, this study is intended to investigate the properties of fresh and hardened mortar with the proportion of expansion additives. With the increase of proportion of expansion additives, the fluidity of mortar shows a decrease while air content increases and setting time gets retarded. It show the satisfactory property in strength at 5% of proportion, and shows more expansion with the increase of proportion of expansion additives and sand/cement ratio. In conclusion, both of strength and expansion reveal appropriate at 10% of proportion of expansion additives.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.285-286
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• 2010

The purpose of this study aimed to evaluate properties of fluidity, compressive strength and bending strength of Loess mortar using non-cement binder to solve indentation due to reduction of compressive strength on exiting Loess bicycle load.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.126-129
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• 2000

To investigate the influence of kinds of cement on state of high-strength concrete, this study deals with the engineering properties of high-strength concrete used 4 kinds of ordinary portland cement. The result of this study be summarized as follows. 1) It appeared that the change in fluidity with time differ with kinds of cement. 2) The difference of setting time was seen over 3 hours according to kinds of cement. Therefore, it must be examined about used materials when high-strength concrete is manufactured in the construction field.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.321-326
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• 1997

Recently, High Range Water Reducing Admixture be used increasingly in other to improve the demanded properties (fluidity, strength, durability etc.) and workability in concrete. These kinds of agent govern quality characteristics (air content, setting time, slump, bleeding etc) by the difference of its dispersing mechanism and performance in manufacture of flowed concrete. Accordingly, in this study, for the purpose of high quality construction in site, the comparative experiment of dispersing ability due to commercially available three types of agent were carried out in paste, mortar and concrete using tow types of cement (I, V). In conclusion, the bleeding reduction by the dispersing ability of agents was verified in the fresh properties of flowed concrete with sea water resistance.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.381-384
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• 1997

It is necessary for manufacturing the high flowing to use the fly-ash as binder of concrete, therefore, Quality of fly-ash is very important to the fluidity of high flowing concrete. In this study, it is comparing and investigating the fludity of high flowing concrete used some fly-ash which it's Ignition loss is 2.44, 4.90, 7.10%. As a result of this experimental study, Ignition loss of fly-ash effects the properties of high flowing concrete, such as air content, flowability, passability etc. but even if valve of ignition loss is upper the specification, properties of high flowing concrete such as setting and hardening time, compressive strength etc.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.162-163
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• 2017

This study investigated the properties of lightweight foamed concrete by using synthetic foaming agent and artificial lightweight aggregate. The effects of artificial lightweight sizes on the compressive strength, density and pore structure of the concrete were investigated. The samples were assessed by MIP analysis and simultaneous SEM was used to study their pore distribution. This study showed the improvement of important properties of lightweight foamed concrete. Lower pore distribution and correspondingly higher compressive strength values were reached. This is for the purpose of providing basic data for the use of lightweight foamed concrete through improvement on the problem such as unstability, falling in fluidity and the strength of existed foaming agent.

• Journal of the Korean Solar Energy Society
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• v.33 no.1
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• pp.66-72
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• 2013

In this study, the thermal conductive characteristics and basic properties of the nine commercial products of bentonite grouts were studied. Six of the nine products for ground heat exchanger systems are imported and others for civil engineering are domestic. The thermal conductivities of all bentonite products are nearly similar among products. The free swell indexes, viscosities and filter losses of the ground heat exchanger grouts are lower than those of the civil engineering ones. These characteristics seem to increase of the fluidity to fill the bentonite slurry to bore-hall perfectly, rather than to prevent underground water penetration. Thus, the mixtures of bentonites and sands are recommended for high thermal conduction grouts.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.413-416
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• 2005

The super early hardening cement is widely used for reducing construction period. But there are some problems with handling the cement because the loss of workability is so big to control. In this study, the fluidity properties of super early hardening cement paste was evaluated at early age of hydration by using gel-time determination method. 4 types of set controlling agent were selected and combinations of them were used for gel-time test. As a result, the gel-time of super early hardening cement paste was extended up to 20 minutes by using the combinations of several types set controlling agent.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.457-460
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• 2008

It was predicted that the most recent technological developments in concrete technology rely on enhanced admixture efficiency rather than on improvement in cement manufacturing. Four major commercially available of organic chemical admixtures are modified lignosulfonates (LS), sulfonated naphthalene-formaldehyde resins (SNF), sulfonated melamine-formaldehyde resins(SMF) and polycarboxylate(PC). In this study, various sulfonated melamine-formaldehyde (SMF) superplasticizers were synthesized via four synthetic steps and reaction conditions such as the mole ratio of melamine to formaldehyde was changed. After application of SMF superplasticizer to cement concrete, the physical properties including workability, slump loss, compressive strength were compared with SNF