• 월간산업보건
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• s.375
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• pp.35-43
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• 2019

• Journal of the Computational Structural Engineering Institute of Korea
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• v.21 no.3
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• pp.287-294
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• 2008

This study proposes a novel method for in service evaluation of tension force of a prestressed 7-wire strand which is frequently employed for retrofitting bridge superstructure. The smart strand is made by replacing the straight king wire of the strand with an instrumented steel tube in which the FBG sensor is embedded. Since the strain of the smart strand can easily be measured using the sensor, it is possible to monitor tension force of the strand during the service. For the sake of demonstrating effectiveness of the proposed strand, we came up with a 7.0m long prototype with 2 FBG sensors, and it is applied as an external tendon to a 6.4m long and 0.6 high RC T-shaped beam. A loading-unloading test has been carried out, and estimated tension forces using the smart strand are compared with measured forces by load cell. The comparison showed that the proposed smart tendon is useful and accurate for monitering tension force of the prestressed tendon.

• Nuclear industry
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• v.37 no.6
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• pp.49-65
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• 2017

본고는 지난 6월 12일 미 캘리포니아 버클리에서 열린 미국원자력학회(ANS) Annual Meeting(6.12~15)에서 Michael Shellenberger 회장이 강연한 내용이다. 이날 기조강연자는 Shellenberger 회장이 유일했다. Shellenberger 회장은 강연 서두에서 "원자력의 평화적 이용을 전파하기 위해 전력을 다하고 있는 한국과 대만을 위시하여 미국의 오하이오와 펜실베이니아, 독일과 프랑스의 원자력 휴머니스트 여러분들께 오늘의 이 말씀을 전하고 싶다."고 밝혔다.

• Journal of the Korea Concrete Institute
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• v.24 no.6
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• pp.727-735
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• 2012

Recently, a high-strength strand of 2400 MPa was developed using domestic technologies. In 2011, KS D 7002 was revised to cover the newly developed high-strength strands to support their practical usage. Presently, however, discussions and evaluations are not sufficient on the mechanical properties of the strands and their performance in structural members. Also, there were no detailed reviews on the need to revise the current design code for practical use of the high-strength strands. In this study, flexural behavior of a member with the high-strength strands was estimated through sectional analysis and a review and comparison of the domestic and foreign design codes were conducted considering the analysis results. Also, the need for the revision of the design code was discussed. Such discussion especially focused on the estimation of the stress in strand, which related with various issues such as determination methods for yield point of strands, time-dependent loss of prestressing force, estimation of stress in strand at member failure, and net strain limit for ductile failure of member. The discussion revealed that some parts in the design code need a revision and the further studies are required.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.145-146
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• 2009

In this paper, feasibility tests of 2200MPa PS strand in terms of wedge and anchor head used currently for 1860MPa PS strand were performed. Static and fatigue tests for PT anchorage systems from 4 companies were conducted in compliance with ETAG013(European Technical Approval Guideline). The test results implied that some of them can be used for 2200MPa PS strand without improvement and some with small improvement.

• The Science & Technology
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• v.30 no.7 s.338
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• pp.20-23
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• 1997

최형섭 한국과학기술단체총연합회 회장은 최근 일본경제신문에서 제정한 닛케이아지아상을 받고 수상기념 강연을 했다. 최회장의 기념강연내용 전문을 게재한다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.5
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• pp.101-108
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• 2008

The primary objective of this research is a study on the pullout bond characteristics of untensioned prestressing strand in concrete. The bond characteristics of untensioned prestressing strand in concrete differs from that of deformed reinforcing bar. In order to use and design untensioned prestressing strand as deformed reinforcing bar, a study for bond characteristics of the untensioned prestressing strand was progressed. Major test variables are embedment length ($10d_b{\sim}60d_b$), concrete cover (45mm, 70mm, 100m) and diameter of strands. (12.7mm : SWPC7, 9.3mm : SWPC7A) As a results, these showed that average bond stress was decreased as a growing the embedment length, and then showed that the bond performance of untensioned prestressing strand was improved if embedment length was above 60$60d_b$.

• Proceedings of the Korean Fiber Society Conference
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• 2002.04a
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• pp.281-284
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• 2002

마 섬유는 흡습성이 좋고 건조가 빠르고, 습윤 시 강도가 증가되며 열전도율이 크고 통기성이 크며, 강도와 내열성이 천연 섬유 중 가장 우수하며 매끄러운 표면을 가지고있어서 광택과 방오성이 좋다. 그러나 세사방적이 어렵고 강연도가 지나치게 커서 의복소재로서 극히 제한적으로 사용되어왔으나, 최근에는 큰 강연도를 장점으로 활용하여 여름용 의복소재로 다시 각광받고 있다. 따라서 면, 레이온, 셀룰로오스계 섬유제품들에 대하여 마 제품과 유사한 효과를 낼 수 있는 다양한 의마가공법이 개발되어왔다[1,2]. (중략)

• 발명특허
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• v.6 no.12 s.70
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• pp.56-56
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• 1981

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.37-38
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• 2009

In this paper, the load transfer test of Korean PS anchorage system was conducted for 1860MPa PS strand and 2200MPa PS strand. The test is in compliance with ETAG013. All the anchorage system tested satisfied the allowance criteria of the test for 1860MPa PS strand but only one of the anchorage systems for 2200MPa PS strand. In order to generally use 2200MPa PS strand to prestressed concrete structures, new anchorage systems shall be developed.