가정 폐기물이 SRF 바이오매스에 미치는 영향 - B시를 중심으로

박재우,이승원,Park, Jae Woo,Lee, Seung-Won 한국환경과학회 2021 한국환경과학회지 Vol.30 No.6

This study investigated the biomass content of fluff type SRF(Solid refuse fuel) operated in B city according to the physical composition. As a result of analyzing the physical composition of SRF, it was investigated that papers 25.2%, fiber 15.1%, vinyl·plastics 42.6%, woods 9.4%, rubbers 1.5%, diapers 3.2% and incombustibles 3.0%. The average of ash and combustible content of SRF was 10.5% and 89.5%, and the higher the proportion of paper and wood, the lower proportion of ash. In addition, the biomass of SRF is 24.9%~58.0%, with an average of 42.6%.

축력과 반복수평력을 받는 TR-CFT기둥에 관한 실험적 연구

박재우,김진호,홍영균,홍기섭,Park, Jai Woo,Kim, Jin Ho,Hong, Young Kyun,Hong, Gi Soup 한국강구조학회 2007 韓國鋼構造學會 論文集 Vol.19 No.4

CFT (Concrete filled steel tube) column has become popular for building construction due to not only its composite effect but also economic effect. However, the conventional CFT column also has its own disadvantages having plastic buckling at the end of column followed by the reduction of strength by yielding of steel tube. An experiment on TR-CFT (Transversely reinforced CFT) column are conducted for making up for conventional CFT column's disadvantages. The experiment parameters are strength of concrete, the layer numbers of carbon fiber sheet. In this study, hysteretic curve, initial stiffness, strength, plastic deformation capacity, and dissipated energy are compared and analyzed between CFT and TR-CFT columns. CFT(Concrete filled steel tube)기둥은 콘크리트와 강관의 이질적인 성질을 상호보완 할 수 있는 구조체 일뿐만 아니라 시공적인 측면에서도 공기단축으로 인한 공사원가 절감으로 인해 최근 널리 사용되고 있다. 그러나 기존CFT기둥은 강관의 항복이후 일정지점의 국부좌굴을 생기는 단점을 지니고 있다. 이를 개선하고자 본 연구에서는 예상국부좌굴위치에 탄소섬유쉬트로 보강을 한 TR(Tranversely reinforced) -CFT기둥에 대해 실험을 수행하였다. 실험변수는 콘크리트강도와 탄소섬유쉬트보강량이며 CFT실험체와 TR-CFT실험체의 이력곡선, 초기강성, 내력, 소성변형능력, 흡수에너지를 각각 비교분석하였다.

탄소섬유쉬트로 보강된 콘크리트충전 원형강관기둥의 연성능력

박재우,홍영균,최성모,Park, Jai-Woo,Hong, Young-Kyun,Choi, Sung-Mo 한국강구조학회 2010 韓國鋼構造學會 論文集 Vol.22 No.2

This paper presents the experiment results for a CFT column confined by carbon fiber sheets(CFSs) under an axial load. Nine specimens were constructed and axial compression tests were conducted. The main experiment parameters were diameter-thickness ratio(D/t), reinforcing CFSa, and the attachment of a cushion gap between surface of steel tube and CFSs. The load-displacement curves of the specimens were obtained from the compression tests. Finally, it was concluded that the CFT column with a gap had grater ductility capacity improvement that the CFT column confined by CFSs. 본 연구에서는 탄소섬유쉬트로 추가구속된 각형 CFT기둥 실험체의 단조압축실험을 수행하였고 이를 토대로 실험체의 연성능력을 평가하였다. 실험변수는 탄소섬유쉬트 보강겹수와 폭-두께비, 갭부착유무이며 실험변수에 따라 총 9개의 실험체를 제작하여 단조압축실험을 수행하였다. 실험을 통하여 각 실험체의 파괴거동, 하중-축변위 곡선, 최대내력, 변형성능을 비교한다. 탄소섬유쉬트의 추가구속은 기둥의 국부좌굴을 지연시켰으며 갭의 부착으로 탄소섬유쉬트의 구속분담시점을 지연시켜 연성능력은 상승한 것으로 나타났다.

사회변동과 대학교육

박재우,Park, Jae-U 한국대학교육협의회 1985 大學敎育 Vol.16 No.-

극저온(20K) 수소동위원소 흡착 등온선의 온도 변화에 대한 자동 저온 부피 교정

박재우,오현철,Park, Jawoo,Oh, Hyunchul 한국재료학회 2019 한국재료학회지 Vol.29 No.5

The gas adsorption isotherm requires accurate measurement for the analysis of porous materials and is used as an index of surface area, pore distribution, and adsorption amount of gas. Basically, adsorption isotherms of porous materials are measured conventionally at 77K and 87K using liquid nitrogen and liquid argon. The cold volume calibration in this conventional method is done simply by splitting a sample cell into two zones (cold and warm volumes) by controlling the level sensor in a Dewar filled with liquid nitrogen or argon. As a result, BET measurement for textural properties is mainly limited to liquefied gases (i.e. $N_2$ or Ar) at atmospheric pressure. In order to independently investigate other gases (e.g. hydrogen isotopes) at cryogenic temperature, a novel temperature control system in the sample cell is required, and consequently cold volume calibration at various temperatures becomes more important. In this study, a cryocooler system is installed in a commercially available BET device to control the sample cell temperature, and the automated cold volume calibration method of temperature variation is introduced. This developed calibration method presents a reliable and reproducible method of cryogenic measurement for hydrogen isotope separation in porous materials, and also provides large flexibility for evaluating various other gases at various temperature.

탄소섬유쉬트(CFRP Sheets)로 보강된 폭두께비가 큰 콘크리트 충전 각형강관 기둥의 중심축하중거동

박재우,유정한,Park, Jai Woo,Yoo, Jung Han 한국강구조학회 2014 韓國鋼構造學會 論文集 Vol.26 No.3

본 연구에서는 콘크리트 충전 각형강관 (CFTP) 단주기둥에 CFRP 쉬트를 횡방향으로 보강하고 중심축하중 실험을 수행하였다. 실험변수는 b/t, CFRP쉬트 보강겹수이며, 총 6개의 실험체가 제작되었다. 실험변수로 사용된 판폭두께비는 b/t는 60, 80, 100이고 CFRP쉬트는 3겹 보강하였다. 실험결과 판폭두께비 100 실험체에서 CFRP쉬트 3겹 보강을 통해 내력을 16% 상승시켜 보강효과를 검증하였다. 내력 저하율을 검토한 결과 국부좌굴이 발생하지 않는 단면강도를 기준으로 최대 41%정도 내력이 저하되었으나, CFRP보강을 통해 32% 정도의 내력이 저하되어 보강효과를 검증할 수 있었다. 하중-변형를 관계를 보면 강재는 항복강도 이전에 국부좌굴이 발생하였으며, CFRP쉬트의 보강을 통해 국부좌굴을 지연시킴을 확인하였다. This paper presents the experimental results of behavior of square CFT columns with large the width-ro thickness ratio strengthened with carbon fiber reinforced polymers (CFRP) sheets subjected to concentrated axial loading. The main parameters were b/t ratio and the number of CFRP layers and 6 specimens were fabricated. The values of b/t were ranged from 60 to 100. From the tests, Maximum increase of 16% was also achieved in axial-load capacity with three transverse layered CFRP applied on four sides of steel tubes. The load capacity decreased up to 41% comparing with nominal load capacity of unstrengthened CFT column. However, for CFRP strengthened CFT, the load capacity decreased up to 32%. Finally, from the load-strain relationships, the local buckling occurred before yield point of steel tubes. Also, from the load-strain relationships, it was observed that local buckling were delayed on CFT columns by CFRP sheets retrofitting.

탄소섬유쉬트로 구속된 콘크리트충전 각형강관기둥의 단조압축실험

박재우,홍영균,홍기섭,이성희,최성모,Park, Jai Woo,Hong, Young Kyun,Hong, Gi Soup,Choi, Sung Mo,Lee, Seoung Hee 한국강구조학회 2009 韓國鋼構造學會 論文集 Vol.21 No.3

This paper presents the experimental results of an experiment on the current rectangular CFT columns and rectangular CFT columns additionally confined by carbon fiber sheets(CFS) under axial loading. The main experimental parameters were the layer numbers of the CFS and the depth-to-thickness ratio. Nine specimens were prepared according to the experimental parameter plans, and axial compression tests were conducted. From the tests, the failure procedure, the load-axial deformation curve, the maximum axial strength, and the deformation capacity of the CFT columns and the confined CFT columns were compared. Finally, it was seen that the maximum axial strengths of the CFT increased more significantly than that of the current CFT columns because of delayed local buckling. 본 연구에서는 기존 각형 CFT기둥 실험체와 탄소섬유쉬트로 추가구속된 각형 CFT기둥 실험체의 단조압축거동 및 압축내력평가에 관한 실험을 수행하였다. 실험변수는 탄소섬유쉬트 보강겹수와 폭-두께비이며, 실험변수에 따라 총 9개의 실험체를 제작하여 단조압축실험을 수행하였다. 실험을 통하여 기존 CFT 실험체와 탄소섬유쉬트로 구속된 CFT 실험체의 파괴거동, 하중-축변위 곡선, 최대내력, 변형성능을 비교한다. 끝으로 탄소섬유쉬트의 추가구속은 기둥의 국부좌굴을 지연시켰으며 이로 인해 실험체의 최대내력이 상승한 것으로 나타났다.

토공사를 위한 건설장비 투입 최적 조합 산정 시스템 개발

박재우,염동준,Park, Jae-Woo,Yeom, Dong-Jun 한국산업융합학회 2020 한국산업융합학회 논문집 Vol.23 No.6

The primary objective of this study is to develop a determination system for an optimal combination of earthwork equipment that improves the traditional way in convenience, prediction accuracy, and productivity. For this, the following research works are conducted sequentially; 1)literature review, 2)technology development trend analysis, 3)develop a determination system for the optimal combination of earthwork equipment, 4)simulation of a developed system. As a result, core considerations are deducted for the development of a determination system. Furthermore, site simulation is performed using a developed system. Site simulation result, Cluster 1(R1200LC 7㎥, CAT 775G 65ton×2) was selected from 6 clusters because of its production cost (￦491/㎥). It is expected that the application range and impact on the construction industry will be enormous due to the availability of the developed system.

탄소섬유쉬트(CFRP Sheets)로 보강된 세장한 각형강관기둥의 중심축하중실험

박재우,최선규,최성모,송동엽,유정한,Park, Jai Woo,Choi, Sun Kyu,Choi, Sung Mo,Song, Dong Yub,Yoo, Jung Han 한국강구조학회 2012 韓國鋼構造學會 論文集 Vol.24 No.6

본 연구에서는 세장판으로 구성된 중공강관(SHS)기둥에 CFRP쉬트로 보강하여 중심축하중 실험을 수행하였다. 총 6개의 실험체를 제작하였으며, 실험변수는 판폭두께비, 보강유무이다. 실험결과 사각단면의 두면은 안쪽으로 국부좌굴이 발생하였으며, 나머지 두 면은 바깥쪽으로 국부좌굴이 발생하였다. CFRP쉬트의 보강을 통해 최대 33%의 내력상승효과를 얻었으며, 초기강성과 연성능력을 비교하였다. 끝으로, 압축극한 내력을 산정식을 제안하여 실험값과 비교하였다. This paper presents the experimental results of axially loaded stub columns of slender steel hollow square section(SHS) strengthened with carbon fiber reinforced polymers(CFRP) sheets. 6 specimens were fabricated and the main parameters were: width-thickness ratio(b/t) and CFRP retrofitting. From the tests, it was observed that two sides would typically buckle outward and the other two sides would buckle inward. A maximum increase of 33% was achieved in axial-load capacity. Also, stiffness and ductility index(DI) were compared between unretrofitted specimens and retrofitted specimens. In the last section, a prediction formula of the ultimate strength developed using the experimental results is presented.

아라미드 FRP 스트립과 강판 사이의 계면 부착응력에 관한 실험적 연구

박재우,류재용,최성모,Park, Jai Woo,Ryoo, Jae Yong,Choi, Sung Mo 한국강구조학회 2015 韓國鋼構造學會 論文集 Vol.27 No.4

본 연구에서는 AFRP 스트립과 강재사이의 부착거동에 관한 실험적 연구를 수행하였다. 실험적 연구를 통해 AFRP 판과 강판사이의 계면부착거동을 관찰하고, 계면부착응력을 산정하는 것이 본 연구의 목표이다. 실험변수로는 부착길이와 AFRP의 두께를 선택하였으며, 18개의 일면전단시편 제작하여 실험을 수행하였다. 실험결과 부착길이와 AFRP 두께가 증가함에 따라 하중값을 증가하였으며, 부착길이와 AFRP 두께가 증가함에 따라 각각 63%, 86%의 하중값이 증가하였다. 끝으로 강재와 AFRP 사이의 부착응력-슬립관계를 산정하였다. 부착응력-슬립관계는 탄성선형거동을 보이고 있으며, 부착길이와 AFRP 두께는 부착응력과 파괴에너지에 영향을 덜 미치는 것으로 나타났다. This paper presents the experimental results for the interfacial bond behaviour between AFRP strip and steel members. The objective of this paper is to examine the interfacial behavior and to evaluate the interfacial bond stress between Aramid FRP strips and steel plates. The test variables were bond length and AFRP thickness. 18 specimens were fabricated and one-face shear type bond tests were conducted in this study. There were two types of failure mode which were debonding and delamination between AFRP strip and steel plates. From the test, the load was increased with the increasing of bond length and AFRP thickness, which was observed that maximum increase of 63 and 86% were also achieved in load with the increasing of bond length and AFRP thickness, respectively. Finally, bond and slip characteristics had the elastic bond-slip model and it was observed that bond strength and fracture energy were not affected by bond length and AFRP thickness.