http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
비정질 붕소강 섬유를 혼입한 콘크리트의 역학적 성능 및 중성자 차폐성능 평가
이준철 ( Lee Jun Cheol ),김화중 ( Kim Wha Jung ) 한국건축시공학회 2017 한국건축시공학회지 Vol.17 No.1
본 연구에서 비정질 붕소강 섬유를 혼입한 콘크리트의 역학적 성능 및 중성자 차폐성능을 평가하였다. 비정질 붕소강 섬유를 콘크리트 체적 대비 0.25%에서 1.0%까지 혼입하여 굳지 않은 콘크리트의 공기량과 슬럼프값, 경화된 콘크리트의 압축강도, 휨강도, 휨인성 및 중성자 차폐성능을 평가하였다. 실험결과, 비정질 붕소강 섬유의 혼입량이 증가할수록 콘크리트의 휨인성 및 중성자 차폐성능이 향상되는 것으로 나타났다. 이를 통해 비정질 붕소강 섬유의 혼입이 중성자차폐성능 뿐만 아니라 역학적 성능을 효과적으로 개선시켜줄 것이라고 기대된다. Mechanical properties and neutron shielding performance of concrete with amorphous boron steel fiber have been investigated in this study. The measurement of this investigation includes air contents, slump loss, compressive strength, flexural strength, flexural toughness and neutron shielding rate. Four different fiber volume fractions were selected ranging from 0.25% to 1.0% by volume for the amorphous boron steel fibers. The testing results showed that the flexural toughness and the neutron shielding rate were increase with the increase of volume fraction for amorphous boron steel fiber. Based on the result, it is concluded that the concrete with the amorphous boron steel fiber can be effectively applied to shield the neutron and to improve mechanical properties.
이준철 ( Lee Jun-chul ),김이성 ( Kim Ie-sung ),김화중 ( Kim Wha-jung ) 한국구조물진단유지관리공학회 2004 한국구조물진단유지관리공학회 학술발표대회 논문집 Vol.8 No.1
It a research trend present in and outside the country is often seen, the structure measurement method of having used PZT and the optical fiber (FBG) will be the actual condition which has accomplished the stock. In order to manage such cracks, time, efforts and expense are required. Such a method has many difficulties in application of a structure by the difficult problem of the measurement range, and the expensive sensor price. Progressive cracks were generated by fracture of glass pipe sensor. Moreover, the experiment which can detect damage propriety by external Light Emitting Diode by damaging a glass pipe by load change with the application of switch using strain gage of a glass pipe was conducted. In this investigation, a reinforcement clothing system was wrapped for a glass pipe sensor. The glass pipe sensor that can make control and reinforce cracks simultaneously.
이준철(Lee, Jun-Cheol),김화중(Kim, Wha-Jung),천우영(Chun, Woo-Yong),이창준(Lee, Chang-Joon) 대한건축학회 2013 大韓建築學會論文集 : 構造系 Vol.29 No.7
This study investigated the effect of microorganisms on compressive strength development of cement paste. The Sporosarcina pasteurii used in this study was capable of microbial induced calcite precipitation(MICP). Four different cell concentrations were selected ranging from 10 to 10? per ml. distilled water as mixing water. From experimental results, cement paste with microorganisms showed higher strength gain compared with reference cement paste at earlier ages. From TG/DSC analysis, more calcium hydroxide was observed in the cement paste with microorganisms. The degree of hydration of the cement paste with microorganisms, evaluated by measuring non-evaporable water contents in cement paste, was also higher than that of reference cement paste. It is very likely that the strength improvement of cement paste is due to acceleration of hydration process caused by the metabolism of microorganisms. Further investigation is in progress to identify the specific mechanisms which is responsible for the improvement of compressive strength in early ages.
[제4분과/구조거동/재료Ⅱ] 리드저항을 이용한 스마트 콘크리트의 개발
이준철(Lee Jun-Chul),김이성(Kim Ie-Sung),김화중(Kim Wha-Jung) 한국구조물진단유지관리학회 2004 한국구조물진단학회 학술발표회논문집 Vol.- No.-
If a research trend present in and outside the country is often seen, the structure measurement method of having used PZT and the optical fiber (FBG) will be the actual condition which has accomplished the stock. In order to manage such cracks, time, efforts and expense are required. Such a method has many difficulties in application of a structure by the difficult problem of the measurement range, and the expensive sensor price. Progressive cracks were generated by fracture of glass pipe sensor. Moreover, the experiment which can detect damage propriety by external Light Emitting Diode by damaging a glass pipe by load change with the application of switch using strain gage of a glass pipe was conducted. In this investigation, a reinforcement clothing system was wrapped for a glass pipe sensor. The glass pipe sensor that can make control and reinforce cracks simultaneously.
김화중(Kim, Wha-Jung),이준철(Lee, Jun-Cheol),천우영(Chun, Woo-Young) 대한건축학회 2015 大韓建築學會論文集 : 構造系 Vol.31 No.12
The microorganisms isolated directly from concrete structures were identified by 16S ribosomal RNA analysis, and a total of 75 microorganisms were finally identified. The DNA sequence information of the 75 microorganisms were registered to GenBank of NCBI (National Center for Biotechnology Information), USA, by the name of each microorganism to make the final report as the microorganisms isolated from concrete structures. These 75 microorganisms were identified and largely classified into three kinds of bacteria. There were 33 High G+C Gram positive Actinobacteria (44.00%), 23 Low G+C Gram positive Bacilli (30.67%), and 19 Gram negative Proteobacteria (25.33%), showing relatively diversely distribution on the concrete structures. The Nucleotide Blast Search of the 75 microorganisms indicated that they consisted of 29 Genus and 49 Species. Actinobacteria were finally identified to be the most prevalent on the concrete structures with relatively diverse species in this study. A variety of effective microorganisms could be assorted from these diverse microorganisms on the concrete structures, and those groups of strains, which are candidates for new species through various physiological and biochemical experiments, are expected to be very important research data from the perspective of environmentally friendly concrete.
김태훈(Kim, Tae-Hoon),이준철(Lee, Jun-Cheol),김화중(Kim, Wha-Jung) 대한건축학회 2015 大韓建築學會論文集 : 構造系 Vol.31 No.2
In construction material field, one of the ways to reduce CO₂ generation and environmental load is to decrease the use of cement materials. In this study, the cement material was replaced with a by-product from iron production which called BFS(blast furnace slag), when mortar specimens were made and it was expected to reduce environmental load significantly. Moreover, the added value can be created by using a by-product and cutting the production cost of concrete and mortar. 5 types of mixing water, BFS and the activator(Ca(OH)₂) were used to make mortar specimens and the compressive strength test was carried out. All specimens were cured for 3, 7, 28days. As a result, all experimental groups had better strength than a control group. Above all, 2F-1 group had superior strength to the others. In order to raise confidence of the results, microstructure of mortar was observed and each specimen was analyzed. SEM images from all groups were compared with each other, and the area and the volume of micro-pore were measured through the porosimeter analysis. Through this research, it was tried to examine the potential for developing zero cement mortar and applying the micro-organism as a natural admixture material.
이창준,이준철,신성우,김화중,Lee, Chang Joon,Lee, Jun Cheol,Shin, Sung Woo,Kim, Wha Jung 한국건축시공학회 2016 한국건축시공학회지 Vol.15 No.4
본 연구에서는 압전소자의 EMI 신호변화를 이용하여 시멘트계 재료의 응결특성을 평가하였다. 시멘트 페이스트에 매립된 PZT센서의 수화시간에 따른 EMI 신호변화를 비카트침 시험과 간이단열시험을 통한 수화온도곡선과 비교하였다. 실험결과, 시멘트 페이스트가 수화함에 따라 PZT센서의 EMI 공진피크와 공진주파수의 변화가 나타났으며, 이러한 변화시점은 비카트침 시험과 간이단열시험을 통한 수화온도곡선으로부터 획득한 응결시간과 부합하는 것으로 나타났다. The evolution of electro-mechanical impedance (EMI) of the piezoelectricity (PZT) sensor was investigated to determine the setting times of cementitious materials in this study. The PZT sensor coated with non-conductive acrylic resin was embedded in cement paste before casting and the EMI signatures were continuously measured. Vicat needle test and semi-adiabatic calorimetry test were also conducted to justify the validity of EMI senssing technique in setting monitoring of cementitious materials. The results show that significant changes in EMI resonant peak magnitude and frequency during setting process were observed, and that the setting times determined by EMI sensing technique were relevant to the setting times measured by Vicat needle test and semi-adiabatic calorimetry test.