• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.2
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• pp.75-86
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• 2012

This paper presents some research results on the shrinkage characteristics and frost resistance before and after cracking of FR-ECC(Fire Resistance-Engineered Cementitious Composite). Also, a waterstop performance and exfoliating resistance of multi-layer lining specimens using FR-ECC and flexural performance of beam member by repaired FR-ECC are estimated in this paper. Experimental results indicate that the plastic shrinkage crack and length change ratio of FR-ECC have been reduced as compared with that of the existing repair mortar, and that its crack resistance on the dry shrinkage is improved under the confining stress. As well as FR-ECC has been great in the frost resistance and its tensile properties under the cracked state have been not reduced by freezing and thawing reaction. In addition, beam member by repaired FR-ECC have been increased in the flexural properties such as initial crack moment, yeild moment, and its crack width has been controled in a stable by the frexural failure.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2007.11a
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• pp.9-13
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• 2007

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.1155-1156
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• 2013

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.174-177
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• 2006

To restore an earthquake damaged community as quickly as possible, well-prepared reconstruction strategy is most essential. This paper reports experimental data on the seismic capacity of diagonal reinforced HPFRCC coupling beams with the Japanese Standard for Seismic Evaluation of Existing RC Buildings. Precast Based on the experimental results, HPFRCC specimen have more residual seismic capacity than RC specimen, but much study is necessary to improve the accuracy of the damage evaluation.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.211-212
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• 2009

In this study, the fresh properties and compressive strength of Strain-Hardening Cement Composites is compared between manufactured by ready-mixed concrete batcher mixer and small mixer in laboratory.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.213-214
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• 2009

In this study, the banding stress and tensile strength of Strain-Hardening Cement Composites is compared between manufactured by ready-mixed concrete batcher mixer and small mixer in laboratory.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2007.04a
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• pp.89-94
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• 2007

• Journal of the Korea Concrete Institute
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• v.25 no.2
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• pp.233-240
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• 2013

In this study, experimental research was carried out to evaluate and improve the seismic performance of high strength R/C interior beam-column joints regions using advanced reinforcing detailings and high ductile fiber-reinforced mortar. Five specimens of retrofitted the beam-column joint regions using advanced reinforcing detailings and high ductile fiber-reinforced mortar were constructed and tested for their retrofitring performances. Specimens designed by retrofitting the interior beam-column joint regions (IJIR series) of existing reinforced concrete building showed a stable mode of failure and an increase in load-carrying capacity. Specimens of IJIR series, designed by the retrofitting of advanced reinforcing detailings and high ductile fiber-reinforced mortar in reinforecd beam-column joint regions increased its maximum load carrying capacity by 114.2~123.5% and its energy dissipation capacity by 1.55~1.85 times in comparison with the standard specimen of SIJC with a displacement ductility of 5.

• Journal of the Korean Society for Heat Treatment
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• v.1 no.1
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• pp.35-43
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• 1988

ADI는 우수한 기계적 성질과 경제성을 바탕으로 80년내 들어 중요한 공업소재의 하나가 되었다. 성공적인 ADI 개발에 중요시 되는 요소로는 오스테나이트화 온도와 시간, 오스템퍼링 온도와 시간, 합금원소, 주물의 질 등이다. 온도와 시간은 ADI의 성능과 매우 밀접한 관계가 있으므로 엄격한 제어가 필요하다. 양질의 주물만이 양질의 ADI을 생산할 수 있으므로 열처리 전 주물의 질에 대한 관리가 필요하다. ADI의 우수한 성능으로는 고강도, 고연성 및 고인성, 내피로성, 내마모성 등이 있다. ADI의 성능을 이용하여 응용될 수 있는 분야는 기어 및 자동차 부품등의 단조강철 대체품과 주조성 및 가공성 등을 이용한 일반 공업제품에 이르기까지 다양하다. 경제적 측면에서의 ADI의 잇점은 생산에너지 및 가공비의 절감 등이다. 새 공업 소재로서의 ADI의 전망은 기술적, 경제적 측면에서 보강되어야 할 사항이 있으나, 이의 최대 장점인 우수한 강도 및 연성, 내 피로성, 파괴인성의 조합적인 기계적 성질과 강철 단조품에 대한 경제성, 주조가 부여하는 부품설계상의 융통성을 바탕으로 대단히 밝다고 할 수 있다.

• The Science & Technology
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• no.3 s.418
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• pp.86-89
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• 2004

사람의 호기심은 무한하다. 예를 들어 키가 몇이면 체중이 얼마이며 나이가 몇살이면 신체구조는 어떻게 변하는지를 알고 싶어한다. 이러한 특수한 쌍의 원리를 규명하려는 시도는 많이 있어왔다. 이번 호에서는 쌍의 불확실성을 규명하려는 양자역학의 불확정성의 원리를 알아본다.