• Computers and Concrete
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• v.5 no.2
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• pp.135-154
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• 2008

This paper presents a nonlinear finite element analysis procedure for the seismic performance assessment of reinforced concrete bridge piers with unbonded reinforcing or prestressing bars. A computer program named RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology) is used to analyze reinforced concrete structures; this program was also used in our study. Tensile, compressive and shear models of cracked concrete and models of reinforcing and prestressing steel were used account for material nonlinearity of reinforced concrete. The smeared crack approach was incorporated. To represent the interaction between unbonded reinforcing or prestressing bar and concrete, an unbonded reinforcing or prestressing bar element based on the finite element method was developed in this study. The proposed numerical method for the seismic performance assessment of reinforced concrete bridge piers with unbonded reinforcing or prestressing bars is verified by comparison of its results with reliable experimental results.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.516-517
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• 2008

The ethylene-propylene (EP) rubbers mixed with one to one ratio is used as an insulation material in the nuclear power plant. It was investigated the effect of the amount of reinforcing agent. moisture absorption and heat treatment on the Ethylene-Propylene(EP) rubbers. The level of degradation was measured by the amount of discharging and. charging currents. When $\gamma$ rays were radiated on the EP rubbers with more charging material, the amount of discharging and charging currents was depended on the amount of reinforcing agent It was verified that the discharging and charging currents irradiated by $\gamma$ rays were higher than those that was not irradiated.

• Journal of the Korean GEO-environmental Society
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• v.3 no.1
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• pp.47-55
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• 2002

The slope reinforcing method utilized in this paper reinforces the ground overall by means of filling borehole as well as permeating grout material into ground by injecting it through the grouting pipe. In order to reflect these characteristics to design, not only the ground reinforcing effect by the structural material itself but also the ground strength improvement effect by the grouting injection must be quantitively evaluated. But precedent research of it has been insufficient. Therefore, the slope reinforcing method was applied to the weathered rockmass slope situated in the highway in order to analyze reinforcing effect and the instrumentation of slope was performed. Through analysis of this field test, the slope reinforcing method was proved to be effective and back analysis method based on instrumentation values of slope was proposed to apply to reinforcing design. In this paper, the effectiveness of reinforcing method was certified through proposed back analysis.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.12
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• pp.841-846
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• 2014

It found that the maximum temperature of the arc discharge occurred on the Silicone rubber sample significantly decreased with increasing the reinforcing agent. It was confirmed that the current value decreased with increasing the aluminium trihydrate($Al(OH)_3$) and the current value increased with reducing the primary resistance over time. Regarding these results, may be it is because the degradation due to the electro-conductive carbonization was improved and the properties of dielectric breakdown was reduced by the flame retardant reinforcing agent. It found that the electro-conductive carbonized road has not happened by increasing the flame retardant reinforcing agent. Regarding to the arc discharge, this study show that the arc arising near the lower electrode of sample has disappeared.

• Journal of the Korean GEO-environmental Society
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• v.13 no.8
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• pp.75-84
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• 2012

In this paper, strength and leaching characteristics of water sludge-added lightweight soils(WALS) considering reinforcing materials(waste fishing net, glue treated waste fishing net and geogrid) and layer(1 or 2 layer) were investigated using unconfined compression test and leaching test. Several specimens of water sludge-added lightweight soil consisted of water sludge, cement, and bottom ash were prepared according to flowability. Reinforcing material added into these specimens were waste fishing net and geogrid. A glue treated waste fishing net was also added in order to increase interlocking between soil mixture and waste fishing net. Strength increased in the order of WALS reinforced by waste fishing net, glue treated waste fishing net, and geogrid. Strength of specimen with double layer-reinforcing material was greater than that of specimen with single layer reinforcing material. Leaching result of WALS was also satisfied with standard of ministry of environment.

• KCI Concrete Journal
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• v.13 no.2
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• pp.42-48
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• 2001

The bend resistance of coated reinforcing bar is greatly influenced by both the adhesion strength between bar and coating materials, and the followed transformation of coating material as bars bend. Especially, tearing state or partial microscopic cracks are predicted on the inside and outside of bending angle, because tensile strength and elongation of polymer film are very different according to types of polymer dispersions in bar coating, and these damaged parts are rapidly corroded by penetration of corrosive factors. In this study, polymer cement slurry coated reinforcing bars with various polymer dispersions are prepared by following combined conditions, polymer-cement ratio of 50% and 100%, coating thickness of 250$\mu$m and 450$\mu$m, coating number, curing age of 3, 7, 14 and 28days. Then the specimens are tested for working life and bend resistance at bending angles $90^{\circ}$, $135^{\circ}$and $180^{\circ}$ to observe the microscopic damage effect as the bars bend. Also, epoxy-coated reinforcing bars for control experiment were used with 250$\mu$m of coating thickness. The tensile strength for polymer films is performed. From the test results, the working life of the polymer cement slurry is within 90 seconds. Among four types of polymer dispersion, polymer cement slurry coated reinforcing bar using St/BA-1 emulsion has the excellent bend resistance, which is remarkably improved than that of epoxy-coated reinforcing bar. And the bend resistance is more related to elongation than tensile strength of polymer film. Polymer cement slurry with a polymer-cement ratio of 100%, a coating thickness of $450\mu$m and one coating using St/BA emulsion is selected as a most suitable coating material for coated reinforcing bar.

• Nuclear Engineering and Technology
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• v.41 no.8
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• pp.1127-1134
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• 2009

Concrete has three major properties after a penetration-reinforcing agent is applied on its surface. First, the durability is improved by the sol-gel process of synthesized material from the polycondensation of TEOS (tetra-ethoxyorthosilicate) and acrylate monomer. Second, the capability to absorb impact energy is reinforced through the formation of a soft and flexible layer of organic monomers by Tea (Tetra Ethyl Amin). Third, the capability to prevent deterioration is enhanced by adding isobutyl-orthosilicate and alcohol. The performance and application of an agent developed through the synthesis of organic and inorganic material in an effort to prevent concrete from deterioration and improve the durability of concrete structures were verified in diverse experiments. The results of these experiments showed that the application of the proposed penetration-reinforcing agent has the effect of increasing the compressive strength by filling up the internal pores of concrete with physically and chemically stable compounds after penetrating the concrete. It also improves the durability against the deterioration factors such as salt water damage, carbonation, freezing and thawing, and compound deterioration. Therefore, it is confirmed that the penetration-reinforcing agent is a useful substance for the management and repair of concrete structures.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.6 s.165
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• pp.1048-1054
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• 1999

It is important to study the shielding effectiveness(SE) of reinforcing material of plastic composite materials against the electromagnetic(EM) waves. In this paper, SE of the shielding material of EM waves was investigated with actual experiments. The materials used in this study were made up of film, fiber and powder of conductive materials - Cu, Al, CF etc. Also, The resin film was used as matrix. The experiment was carried out by using a shielding evaluator(Shielding box) TR17302 with an ADVANTEST spectrum analyzer, model R3361C. It was found from the experimental results that copper, aluminum and carbon fiber were good candidates as a shielding material against the EM waves with increasing the SE as the composite was laminated. The characteristics of the SE against the EM waves depended on a mode of preparation of specimen. The effects of interval of wires on the SE were studied when the orientation and the space of Cu wires were changed. The SE strongly depended on the. orientation and the space of the Cu wire. SE decreased as the space of the Cu wires was increasing.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.67-68
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• 2017

This paper discusses the application of civil structure use reinforcing fiber mixed with concrete to be used as protection layer of waterproofing material and root resistant layer installed in below-grade parking lot upper slab of residential building. A performance evaluation under the prescribed method outlined in KS F 4938 was used for this new material. The testing results showed that the fiber reinforcement can be used to strengthen the protection for the waterproofing material. Also, plants that were planted in June 2016 have not yet penetrated the specimens used for root resistance testing. The domestic root resistance performance testing usually covers the period of 2 years, thus further observation to make any conclusion about the root resistance property is required.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.10a
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• pp.781-786
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• 2002

We develop the performance improving agent of penetration reinforcing applied on concrete by which main components use compounds of metal alkoxide and silicate(Ti). Also, we investigate on the type and amount of organic solvent which need the hydrolysis and water condensation reaction of Ti. The penetration reinforcing agent developed this study can penetrate deeper than 50mm without relation to concrete strength. Also the performance improving agent composed of the combination of Ti and organic solvent A, improve performance in keeping out or removement of deterioration material. waterproof and strength.