• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.155-160
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• 2000

In this paper, we investigated quality properties for the expansive of the CaO-$CaSO_4$ family which used to compensate dry-shrinkage in the floor mortar of On-Dol heating System. This experimental study established the mix condition with quantity of the expansive and is to investigate the relativity between the compress strength and the length change and the relativity between the chemical properties and the length change with the analysis of the physical and chemical properties. As a result of the study, the expansive is controlled by more the CaO than the $CaSO_4$. The relativity between the compress strength and the length change is expressed by exponential function, showing that if the expansive performance is increased, the compress strength is decreased. And the relativity between the chemical properties and the length change is only relative the quantity of the F-CaO among the chemical properties, is expressed by the second order function, showing that if the F-CaO is increased, the expansive performance is increased.

• Food Science and Preservation
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• v.7 no.1
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• pp.63-67
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• 2000

Changes in the compressive strength of four typical corrugating mediums (K$_2$A, AS and S) as affected by relative humidity conditions were compared and their relative cost effectiveness was analysed. All mediums lost their compressive strength as relative humidity increased. at the relative humidity of 93% , As medium lost 58% of its initial strength while S medium did about 40%. Calculations of compress factor and compress factor by price indicated that $K_2$ medium was the most cost effective and maintained the highest compressive strength among the mediums tested. It was recommended that $K_2$ medium could be effectively used to make corrugated fiberboard especially for fresh agricultural product packaging .

• KIEAE Journal
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• v.8 no.5
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• pp.55-60
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• 2008

The purpose of this study is to increase the use of Hwangto and examine the strength according to what it is compounded with. Hwangto-concrete containing Hwanto without cement nor organic chemical products were compared to the traditional cement concrete through some durability experiments. We expect to gain more knowledge on the potentials of Hwangto-concrete as an architectural source. 1) As Hwangto binder amount rises, the value of slump increases too. The reason is that the increase of the quantity of cement causes the increase of the amount of material and the decrease of the amount of aggregate. 2) When the mixed component into Hwangto-concrete remains at 2%, the compress strength is generally dispersed high along the per unit fission, in case the amount of which is at $400(g/m^3)$. The highest compress strength is 39MPa. It means that it can be applied to common structures and we need to conduct a basic property test to ensure the strength and fluidness. 3) Hwangto-concrete is expected to be highly used in the ocean structure and chemical industry because it has better resistance to sulfuric acid and to hydrochloric acid than the cement-concrete has. The result of this study is as follows. It is expected that Hwangto-concrete will be widely applied and further research on its durability and tests for its basic substantial characteristics based on future component added to it.

• Journal of Industrial Technology
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• v.18
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• pp.363-370
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• 1998

This study focused on the development of an alternative stress estimation procedure to instantly calculate the critical stresses bonded concrete pavement. Closed form analysis is commonly used to analyze pavement structures. This type of analysis assumes linearelastic material properties and static loading conditions. The well-known ILLI-SLAB finite element program was used for the analysis. Bonded concrete overlay analyzed the stress distribution, behavior and load carrying capacity under track load is made evaluation standard of bonded concrete overlay. In the study, the following results were derived ; The properties of strength is that compress and 3-point bending strength of existing pavement is deteriorated with $184kg/cm^2$, $59kg/cm^2$ but compress and splitting tensile strength of overlay is satisfied with $465kg/cm^2$, $45kg/cm^2$. Load transfers is happen at adjacent slab by interlocking under track load. The stress distribution under interior, corner and edge load is described high loading position surrounding then loading position.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.585-588
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• 1999

This study is performed to verify the effect of CSA expansive additives for concrete by material properties test and 4 point-bendig test of RC slabs. The result shows that the variations of compress strength, bending strength, and modulus of elasticity of expansive concrete are the same as those of plain concrete. And the crack load of RC slabs with expansive concrete are increased in comparision with that of plain concrete, but the ultimate strength of RC slabs with expansive concrete is decreased.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.53-54
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• 2015

As the result of uniaxial compression strength test on the CLMS mixing BFS and SS with BFS 4000, it required to determine the desired strength through increasing unit quantity of cement in mixing process because of dramatic strength deterioration of strength according to increasing replacing rate. In this study's result, regardless of differences in fine aggregates used, in order to get uniaxial compression strength in the scope exceeding criteria of minimum strength for applying to the field, the most reasonable combination was to mix replacing BFS with fineness of 6000 in 30%. For the CLMS mixing BFS and SS, in order to improve flow ability by securing quantity of minimum unit and to repress bleeding rate with securing uniaxial compress strength considering the field applicability, regardless of differences in fine aggregates used, to mix BFS over 6000 in 30% was most effective.

• Journal of Korean Neurosurgical Society
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• v.49 no.2
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• pp.139-141
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• 2011

Compression of the ulnar nerve in Guyon's canal can result from repeated blunt trauma, fracture of the hamate's hook, and arterial thrombosis or aneurysm. In addition, conditions such as ganglia, rheumatoid arthritis and ulnar artery disease can rapidly compress the ulnar nerve in Guyon's canal. A ganglion cyst can acutely protrude or grow, which also might compress the ulnar nerve. So, clinicians should consider a ganglion cyst in Guyon's canal as a possible underlying cause of ulnar nerve compression in patients with a sudden decrease in hand strength. We believe that early decompression with removal of the ganglion is very important to promote complete recovery.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.853-858
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• 2000

According to the results of this research, Production of Fold Mortar Permanent - Form was found to be possible by Mortar. Th FP-Form (Fold Permanent-Form) mortar had compress strength 580kgf/$\textrm{cm}^2$. FP-Form model was made by the result of the first research. There was no minute-crack on beam form and the outer surface of form was very smooth, and those qualities it were made possible hand-mad by experiment. This study is about bond strength progress of FP-Form that developed for the form work rationalization and systematization. The result of this study follows; (1) Fluidity and strength development of mortar which used for FP-Form are satisfied (2) After study on getting good bond strength progress, inside-uneven type presents the better suitableness, and wire netting V-type presents the better shear strength.

• Geomechanics and Engineering
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• v.23 no.2
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• pp.179-187
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• 2020

Freezing-thawing cycles have significant effect on soils engineering behavior in frozen areas. This effect is more considerable in fine-graded than coarse-grained soils. The objective of this study is improving soil durability and strength in continues freezing-thawing cycles. For getting this purpose mixture of Polyvinyl Acetate (PVAc) and Ethylene Glycol Monobutyl Ether (EGBE) has been added to fine-grained soil and final prepared samples were tested at different freezing-thawing cycles. PVAc was mixed with 1%, 2% and 3% of soil weight. Half of PVAc weight was used as weight of EGBE. Freezing-Thawing cycles were exposed to samples and they were tested at different cycles. Results showed that adding mixture of PVAc+EGBE improved strength and durability of samples up to 10 freezing-thawing cycles. Unconfined compress strength tests were applied to samples and stress and strain of samples were tested on failure time. Behavior of samples was different at different percentages of mixture. Results showed that increasing amount of PVAc from 1% to 2% had more considerable effect on final stress than 2% to 3%. Using higher percentages of PVAc + EGBE mixture leaded to that samples carried more strain before collapsing. Another result gained from tests was that, freezing-thawing effect was more considerable after fourth cycles. It means differences between first and fourth cycles were more considerable than differences between fourth and tenth.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.657-660
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• 2006

HPFRCCs(High performance fiber reinforced cementitious composites) exhibit characteristics of strain harding and multiple crack. These lead to improvement in ductility, toughness, and deformation capacity under compressive and tensile stress. These properties of HPFRCCs are affected by type of fiber, size of sand. Furthermore these influence compress strength and flexural strength. Therefore experimental study on the mechanical properties of HPFRCCs using PVA fiber was carried out. In this paper, HPFRCCs made of PVA fiber were tested with size of sand, strength of concrete to evaluate characteristics of compressive strength and flexural strength.