• Korean Journal of Microbiology
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• v.12 no.3
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• pp.147-148
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• 1974

A small amount of Duco cement or Elmer's clear cement was dropped on a slide glass and immediately spread with a glass rod or woden stick a thin film on the surface. After approximately 1 minute a small amount of rubber cement was spread on the top of the film of Duco cement using the same method as described earlier. It was important that the rubber cement be smeared before the Duco cement dried out. These two kinds of cements must not be mixed. It was better to make the film of the rubber cement slightly thicker than the film of Duco cement. This composite film may be used up to several months after preparation. The sample leaf was placted on the slide, prepared with adhesive and the leaf surface was passed on the film with the thumb. The pressing was done so the leaf surface was completely in contact with the film. Then the leaf was peeled from the slide.

• The Journal of the Korean dental association
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• v.10 no.8
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• pp.531-534
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• 1972

The author measured exothermic temperature of the 5 kinds of zinc phosphate cement and 3 kinds of copper phosphate cement during setting process. Cements were mixed on the glass slab with flexible steel spatula at room temperature (25.8℃) for one minute (spatulating speed was 100 strokes per minute) and placed in the incubator of which temperature was held at 37℃ and thermometer was inserted into the cement mass. The powder liquid ration was 3.0gm:1ml and 1.5gm:1ml. The results were as follows. 1) The heat generated after mixing these cements was under 47.22℃. 2) The range of thermal change of the zinc phosphate cements during setting process was wider than copper phosphate cements. 3) The exothermic temperature from the thin mix was higher than thick mix. 4) The exothermic temperature of the zinc phosphate cements was higher than copper phosphate cements.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.667-670
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• 1999

There are a large number of deteriorate mechanisms on the reinforced concrete structure and it acts complexly. In case of carbonation, it effected by environmental condition as well as properties of concrete. Most of all, water cement ratio and finishing materials have a great effect on the carbonation velocity. So, it is then aim of this study to suggest elementary data for the prediction of remaining life and the durability design by studying the relationship between carbonation velocity and permeability according to the waste cement ratio and kinds of finishing materials

• Journal of the Korean Geotechnical Society
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• v.18 no.6
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• pp.61-72
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• 2002

In this study, model tests were performed to evaluate the injection characteristics of cement grouting which was used as waterproof method for leakage of underground structures. To simulate in situ condition, model tests were performed with varying the ground conditions such as the kinds of test soils, soil density, water content, etc. and the injection conditions such as kinds of injection materials, injection pressure, injection quantity, injection velocity, etc. From the results of model tests, the major factors influencing the permeability of injection material were determined to be the kinds of soils and soil density. To obtain optimal injection effects, injection should be performed after investigating the condition of backside ground accurately.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.47-52
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• 2000

Recently, it is very necessary the development of the manufacturing techniques for high strength concrete(HSC) for the large-scale size and good quality of civil structure. But, the manufacture and quality control of HSC of which shrinkage, heat of hydration and workability at construction filed are considered, is very difficult due to its low water-cement ratio and high quantity of unit cement content. In the present study, we tried to know and assess the influences of chemical and physical properties of cement on the material properties of HSC. We analyzed basic properties of 4 kinds of cement whose chemical and physical properties are different each other through various tests such as chemical analysis and mortal test. Also, we performed the assessment of the material properties of HSC for each dement by the test for the conditions of same mix design and similar compressive strength. From the results in the study, the assessment of the important quality factors of cement influencing the properties of HSC may be utilized to quality control of applied cement to manufacture the HSC of high quality.

• The Journal of Korean Academy of Prosthodontics
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• v.13 no.1
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• pp.23-26
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• 1975

The purpose of this study was to measure the retentive force of various kinds of dental cement. Cross-cutting the half of the occlusal surface, pinholes were prepared on the dentin with No. 557 carbide bur. No. 557 steel burs were cemented in the pinholes and retentive force was measured by removing the burs with Instron testing machine. The Instron testing machine was operated at a rate of 0.2 cm per minute. The following results were obtained : 1. The retentive force of zinc phosphate cement(A), reinforced zinc oxide and eugenol cement and polycarboxylate cement were similar to each other, but that of zinc phosphate cement (A) was the highest of all. 2. The retentive force of zinc phosphate cement (B) was the lowest of all.

• 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.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.220-223
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• 2004

It is fact that the cement is the most important material to harden the mortar and concrete, and Potland cement is used widely. Also, the chemical and physical properties of cement are different according to the kinds of cement. This is an experimental study to compare and analyze the influence of cement strength on the compressive strength of mortar to improve the quality of mortar and concrete. According to test results, it was found that correlation between cement strength and mortar strength was very high in all mixture.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.293-298
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• 1997

Corrosion of steel reinforcing in concrete deteriorated by freezing/thawing and carbonation was characterized. Concrete specimens were prepared using various kinds of cements such as ordinary portland cement (type I), low heat portland cement (type IV, belite rich cement), sulphate resistance portland cement (type V), blast furnace slag portland cement and ternary blended cement. Of various cements, type V and type IV with lower $C_3A$ content revealed better steel corrosion resistance after freezing/thawing and carbonation. $C_3A$ content in cement might affect freezing/thawing resistance in sea water.

• Restorative Dentistry and Endodontics
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• v.22 no.2
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• pp.596-608
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• 1997

The purpose of this study was to compare the apical leakage and adaptation to the dentinal wall of a glass ionomer root canal cement(Ketac-Endo) with those of AH-26 and Tubli-Seal. 102 single-rooted teeth were insrumented with step-back technique and randomly divided into four groups according to kinds of root canal cements: Ketac-Endo, AH-26, Tubli-Seal, and no root canal cement. Four experimental groups were as follows; Group 1 : Filling with gutta-percha and Ketac-Endo Group 2 : Filling with gutta-percha and AH-26 Group 3 : Filling with gutta-percha and Tubli-Seal Group 4 : Filling with gutta-percha without root canal cement All the specimens were obturated with lateral condensation technique, and stored in 100% humidity for 4 days. 20 teeth in each group were placed in centrifuge tube filled with India ink, and then centrifuged for 20 minutes at 3,000 rpm. And they were evaluated for linear dye leakage using a stereoscope and analyzed by one-way ANOVA. 22 teeth were split longitudinally and evaluated the adaptation to the dentinal wall using scanning electron microscope(4 teeth in each group) and stereoscope(2 teeth in 1, 2, 3 group). The obtained results were as follows ; 1. In case of not used root canal cement(Group 4), there was showed much degree of dye penetration comparerd with used root canal cements (Group 1, 2, 3)(P<0.01). 2. In the case of used root canal cements(Group 1, 2, 3), there was no significant difference in linear leakage in groups(P>0.01). 3. In the case of used root canal cements(Group 1, 2, 3), there was showed intimate adaptation to the dentinal wall independent on kinds of root canal cements. 4. Fractured surfaces indicated failure of cohesion in Ketac-Endo, and failure of adhesion to dentine in AH-26 and Tubli-Seal. 5. According to similar apical leakage and adaptability to the dentinal wall to another root canal cements, it is possible to be used glass-ionomer cement as root canal cement.