• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2013.05a
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• pp.206-206
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• 2013

산악자전거 서스펜션 포크 프레임의 소재 개발을 위해 Si, Mn, Mg, Cr, Zn 원소의 첨가량을 조정한 500MPa 인장강도를 가지는 압출성형과 용접성이 우수한 알루미늄 합금을 개발하였다. 개발한 고비강도 경량 알루미늄합금 위에 고경도, 고기능성과 같은 우수한 기계적 물성을 가진 TiN 박막을 Arc ion plating 공정으로 코팅하여 알루미늄합금의 내부식성, 내구성을 향상시켰다.

• Journal of the Korea Institute of Building Construction
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• v.18 no.6
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• pp.543-550
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• 2018

The RC buildings which are constructed on the seaside are followed by KBC(2016) to achieve the minimization of durability damage. To control the corrosion of the reinforcing steel bar by salt attack, W/C should be under 0.4 and specified concrete strength is higher than 35MPa in the concrete/building construction standard specification. Even though it has been proved that the concrete mixed with mineral admixture such as blast furnace slag and fly ash etc. have high strength and durability in previous researches, the beneficial informations are not applied to the codes. Ready-mixed concretes which usually include the admixtures in Busan were tested to certify the salt attack durability. In the same specified concrete strength, remarkable salt attack durability was evaluated in comparison to OPC. For economical and reliable durability design, chloride ion diffusivity should be measured before applying to new building construction.

• Proceedings of the Korean Reliability Society Conference
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• 2000.04a
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• pp.73-79
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• 2000

본 논문은 BCPS(Balanced canister purge solenoid valve) 의 Lab. 내구 시험 Spec. 결정 방법에 관한 것이다. BCPS 는 기존에 사용 중인 CPS(Canister purge solenoid valve) 의 응답성과 제어의 용이성을 좋게 하여 배기 가스 특성을 향상시키기 위해 CPS 내부에 Rubber 재질의 막(Diaphragm) 을 적용한 것이다. 하지만 이 Diaphragm 이 마모 등에 의해서 찢어지면, 오히려 배기 특성이 저하된다. 따라서 BCPS의 적용을 위해서는 이 Diaphragm 의 내구성이 검증되어야 하며, 이를 위해서는 새로운 신뢰성 시험 Spec. 의 개발이 필요하다. 본 연구에서는 BCPS Diaphragm의 검증을 위해 필요한 신뢰성 시험 Spec. 을 결정하였다. 이를 위해, X-ray Inspection System등을 이용하여 부압에 따른 Diaphragm 의 형상 변화 등을 관찰하였으며, 실제 차량에서 Diaphragm 에 걸리는 압력의 분포를 측정하였다.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.99-106
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• 2005

본 연구에서는 케이싱을 영구부재로 사용함으로써 기존의 현장타설말뚝과 비교하여 시공 성,품질균일성,경제성, 내구성 등을 검토한다. 연구결과 케이싱을 영구부재로 사용하는 경우, 케이싱의 재사용을 위한 인발작업이 불필요하게 되고,말뚝길이전체에 대하여 케이싱을 사용한다면 R.C.D공법에 서 적용하는 슬러리공벽보호공정이 불필요하므로 시공성이 향상되는 것으로 판단된다. 케이싱을 영구부 재로 사용하는 현장타설말뚝의 지지력은 일반 깊은 기초의 지지력을 산정하는 방법과 동일하게 구해질 수 있다. 대구경의 영구케이싱이 있는 현장타설말뚝을 시공한다면 공내에 간단한 장비와 인력을 투입해서 선단부를 그라우팅방법 등으로 강화시킴으로써 선단지지력을 효과적으로 증대시킬 수 있을 것이다. 또한 케이싱 내부로부터 미리제작한 구멍을 통하여 그라우팅, 전단키(shear key) 등을 주입 또는 압입 함으로써 주면마찰력도 크게 향상될 수 있을 것으로 사료된다.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.535-536
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• 2009

This study was carry out to evaluate the durability of Ductile Fiber Reinforced Cementitious Composites(DFRCC) according to W/B ratio(30, 40, 50%). The results is showing that DFRCC outstandingly improved to compare to plain concrete for the resistance of chloride ion penetration and rapid freezing and thawing

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.108-109
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• 2014

The purpose of this study is to enhance durability of solidifying mat. solidifying mat excellent mechanical properties of geotextile. multi-layer coating system is applied to the mat and the chloride ions penetration resistance, chemical resistance, accelerated carbonation test were evaluated by testing the durability. Durability test results are as follows. chloride ions penetration resistance results are coated mat is approximately 70 % lower than plain. chemical resistance test results are coated mat no discoloration. accelerated carbonation test results are coated mat is approximately 90 % lower than the plain.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.339-340
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• 2018

Contemporary concrete structures make use of underground spaces as parking lots and other comfort facilities for efficiency purposes. As underground environmental conditions are in constant exposure to degradation factors from the environment such as groundwater, hydraulic and soil pressure, structural movement and settlement, structural defects in the form of leakage occur. Current maintenance regulations and regimes are unable to respond to this field, as degradation mechanisms in underground environments are still unclear. In this regard, this study proposes the utilization of integrated information sharing system that can provide various technical information for construction designs to prevent leakages in underground concrete structures.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.6
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• pp.29-34
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• 2017

This study analyzed automobile lower arm assembly structure and fatigue to identify configuration changes to enhance structural safety. Parts connected to the car body were fixed and 500 N load was applied at the lower arm head. Maximum equivalent stress and maximum total deformation were minimized for model 1 ( MPa and 0.10315 mm, respectively). Fatigue analysis using extreme SAE bracket history fatigue loads showed model 1 also improved fatigue life ($3.3693{\times}10^5cycles$). This study provides important inputs to improve lower arm durability by modifying the arm configuration.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.36-37
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• 2021

When the final finish of a building is designed with base concrete, complex deterioration occurs due to the harsh environment such as shrinkage and expansion due to external temperature changes, freezing and thawing, and the use of calcium chloride due to snow accumulation. Therefore, the pozzolanic reaction mechanism of blast furnace slag is clearly identified, and the causal relationship between the material properties and performance of the blast furnace slag is identified to present guidelines for mixing high-durability concrete.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.1
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• pp.56-63
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• 2016

This experiment was compared and analyzed between the original surface paint through chloride penetration, neutralization, freeze-thaw and chemical corrosion resistance measuring internal structure and volume of voids in order to evaluate the effect of increase in durability of the newly modeled nano synthesized polymer paint painted on concrete surface which results improvement on air permeability to increase the durability of concrete structures. The test result of measuring volume of void and inner structure, concrete, spreaded with nano synthesized polymer paint, showed decreasing trend of pore volume in the range of less than $0.1{\mu}m$ and more than $0.3{\mu}m$. Also, using an electron microscope inside showed tightness of hydration texture. Chloride penetration depth of concrete, painted with nano synthesized polymer paint, was decreased more than 92% compared to non-painted concrete and 70% with water-based epoxy painted concrete. Especially, chemical corrosion resistance test set with aqueous solution of 5% sulfuric acid, non-painted concrete and water-based epoxy painted concrete showed weight loss of 4% after dipping for 12 days. On the other hand, concrete painted with nano synthesized polymer paint showed 1.7% weight loss under the same condition. Also, it showed great result of appearance under the criteria of Tsivilis et al.