• Proceedings of the KSR Conference
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• 2005.05a
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• pp.391-396
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• 2005

Salt water spray test and salt water immersion test were experimentally conducted in order to investigate the durability of fiber reinforced composites under salt water environment. The specimens were made of glass fabric reinforcement and phenolic resin. Mechanical test was performed to obtain mechanical properties such as tensile properties, flexural properties, and shear properties by varying with exposure times. Also dynamic mechanical test and FTIR were conducted to investigate a change in chemical structure as well as thermal analysis properties such as storage shear modulus, loss shear moduls, and tan ${\delta}$. According to the results, salt water environment has effected on mechanical properties and thermal analysis properties and especially the durability of glass fabric/phenolic composites were severely affected on salt water immersion environment rather than salt water spray environment.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.339-344
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• 1997

During recent years the durability of concrete structures has attracted considerable interest in concrete practice, material research and long-term deformation. To preserve the brittleness of concrete as well as energy absorption and impact resistance, amount of fiber usage has greatly increased year to year in the field of public works. When fly ash, fine powder, mixed into concrete, it condensed the void of concrete structure. Expecially, there's a great effect for strength improvement of concrete by initial pozzolanic reactions. Pozzolan reaction, between cement particle and fly ash, can elaborate the micro structure of matrix. So it was able to improve the effect of fiber reinforced by increased adhesion between cement paste and steel fiber. And so, in this paper, we dealt SFRC for the purpose of efficiently using of industrial by-products and its economical manufacturing. Also we performed the test for durability such as chemical resistance, freeze-thaw resistance and accelerated carbonation of SFRC using fly ash.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2003.11a
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• pp.63-67
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• 2003

There are many factors that generate the early deterioration of the concrete structure. As the one of the representative factors, we can think an invasion of the water, air and so on. The water and air invade in inside void along the capillarity and they become the cause that the durability like corrosion of layer department due to freezing and thawing, inside steel frame corrosion, and so on blacks. Therefore with covering permeability covering waterproofing material of fluid condition in outer wall, intercepting the deterioration factor due to the infiltration of water from outside and for salt damage of concrete layer department, freezing damage and neutralization, it needs, to improve durability of structure. This study separately examined physical and chemical specific of quality liguid siliceous of waterproofing material. Therefore as this applys the construction site, it improves the durability of concrete structure. Further this presents the application plan from the construction market against the new material.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2003.05a
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• pp.63-67
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• 2003

There are many factors that generate the early deterioration of the concrete structure. As the one of the representative factors, we can think an invasion of the water, air and so on. The water and air invade in inside void along the capillarity and they become the cause that the durability like corrosion of layer department due to freezing and thawing, inside steel frame corrosion, and so on blacks. Therefore with covering permeability covering waterproofing material of fluid condition in outer wall, intercepting the deterioration factor due to the infiltration of water from outside and for salt damage of concrete layer department, freezing damage and neutralization, it needs to improve durability of structure. This study separately examined physical and chemical specific of quality liquid siliceous of waterproofing material. Therefore as this applys the construction site, it improves the durability of concrete structure. Further this presents the application plan from the construction market against the new material.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.649-652
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• 2006

The exist waterproofing membrane cause not to assure proper thickness in constructing. It become a serious problem which as decreasing of durability, waterproofing membrane to be tom and break down. Therefore, it is necessary that the expert have to construct waterproof works,, if not, it can be frost and thawing or chemical corrosion called one of the reason in maintaining the safety of concrete structure. In summarize, for this paper, it would be understand that exposed and compound experimental study of waterproofing sheet using coat material filling into the protuberance to improve the durability for concrete structure can widely apply to field to solve the these significant problem.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.621-624
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• 2006

In this study, the repair method using PVA fiber reinforced mortar evaluated on durability performance. Test of salt injury, carbonation, freezing-thawing, chemical attack, permeability was performed As for the test results, it was found that durability performance of the repair method using PVA fiber mortar showed more better than the existing repair method. Therefore, appling on the repair method using PVA fiber reinforced mortar, the repaired concrete structures can be increased to service life.

• Advances in nano research
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• v.5 no.2
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• pp.99-111
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• 2017

Nano particles have been gaining increasing attention and applied in many fields to fabricate new materials with novel functions due to their unique physical and chemical properties. In the present study two nano materials, namely nano silica (NS) and nano clay metakaolin (NMK) were partially replaced with ordinary Portland cement (OPC). The replacement level was varied from 0.5 to 2.0% in OPC and blended in cement mortar with a water cement ratio of 0.40. Mechanical property studies and durability experiments such as compressive strength, tensile strength, water absorption, depth of chloride penetration test. Nano silica was synthesized from rice husk ash and analyze the size using particle size analyzer. The results indicate that the compressive and tensile strength of the cement mortars containing nano materials were higher strength compared to the plain mortar with the same water cement ratio.

• Membrane Journal
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• v.30 no.6
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• pp.443-449
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• 2020

In this study, CO2 separation experiment was performed on a CH4/CO2 mixed gas using a ceramic hollow fiber membrane contactor module (HFMC). In order to fabricate high-durability HFMC, a high-durability hollow fiber membrane was prepared and evaluated. HFMC was fabricated using the prepared hollow fiber membrane, and the experiment used a mixture of CH4/CO2 (30% CO2, CH4 balance) and monoethanolamine (MEA). During HFMC operation, the effect of gas and absorbent pressure on the CO2 removal efficiency was evaluated. The CO2 removal efficiency increased as the gas pressure increased, and the CO2 absorption flux also showed a tendency to increase with the liquid flow rate. In addition, when the CO2 absorption rate was less than 40%, LTS-1, a counter-current form where the absorbent enters from the bottom, has higher CO2 removal performance than LTS-2, a countercurrent form in which the absorbent enters from the top. and when the absorption rate was 40% or higher, LTS-2 had higher performance than LTS-1.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.399-402
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• 2000

When concrete structures are built in marine environment, they may be deteriorated and have the poor durability and quality caused by steel corrosion or by chemical attack of magnesium or sulfate ions. Especially, Mg ions contained in seawater make concrete surface weaken by chemical reaction with $Ca(OH)_2$ In this study, a concrete structure built in 1947 was investigated to estimate the factors, especially chemical attack, which can cause concrete to deteriorate. Furthermore, the instrumental analysis methods such as XRD and ESEM were performed to find the reactants in concrete under marine environment.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.651-656
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• 2003

Durability of concrete is possibly related to externally-induced chemical attacks in addition to internally-induced deterioration. Externally-induced chemical attacks can be derived from various sources according to environmental conditions under which concrete structures are existing. The present study investigates the characteristic concrete deterioration and formation of secondary minerals by external chemical attacks under certain environmental condition. Petrographic microscope, SEM, EDAX, XRD analyses were conducted to identify secondary mineral formation and micro-structural analyses.