• Title/Summary/Keyword: PCCP

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The Research and Application of Protective Coating for PCCP

  • Lin, Zhu;Xu, Cuizhu;Zhang, Li;Fan, Yunpeng;Zhang, Qibin
    • Corrosion Science and Technology
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    • v.7 no.5
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    • pp.265-268
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    • 2008
  • Prestressed Concrete Cylinder Pipe(PCCP) had became one of the dominating kinds of pipes substituting for steel pipes because of its unique feature (high intensity, high pressure and high leakproofness). PCCP was produced firstly by Bonna company in France. By the end of 20th century, there were over 19000 km of this product installed in America. PCCP was introduced from Ameron company by Shandong Eletric Power Pipeline Engineering Company in 1988. As the statistical data in 2002, 700 km of PCCP had been applied in China, and the application trended towards rapid increase.Since prestressing wire would be corroded in environment, Several accidents due to the breakdown of pipe had happened. Consequently the external wall of pipe should be covered with protective coatings. There was a lack of technical study in corrosion and control of PCCP, because PCCP had been applied for a short time in China. in order to ensure the service life of PCCP, we have developed a kind of protective coating for concrete pipe, which had high intensity and anti-corrosive property with convenient applicability. The physical and chemical properties, painting technology and field application of this coating was introduced in the paper, at the same time, the future of external protective coating for PCCP was looked into.

PCCR(ECCP) Design of Great Man-made River Project (GMR 공사에 적용된 PCCP(EC)의 설계)

  • 김영수;최인식;신경수;김두영;이원재
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.10b
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    • pp.686-693
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    • 1998
  • Prestressed Concrete Cylinder Pipe(PCCP) is used in water transmission pipeline of the Great Man-made River Project(GMR Project). In domestic area, PCCP is used for water cooling systems of Uljin and Youngkwang nuclear power plants. In abroad, especially in the United States and Canada PCCP supplies virtually every metropolitan area with raw and treated water. Compared with other pipe types, PCCP manufacturing cost is dear. But total cost can be considered as economical due to low installation and maintenance cost. Previously, the designs of PCCP were generally determined from one of two appendices in American Water Works Association(AWWA)standard C301 which provided two design methods-cubic parabola design method and stress analysis design method. In 1992, the design procedure for PCCP expanded from two alternatives to the most huge and complex AWWA standard C304. Because C304is so large, it takes too much time for the engineer to read and understand the design concepts and procedures. In this paper, the AWWA C304 design procedures are segmented into simple, understandable sections and concepts and explained. Each section or concepts is compared to the previous design procedure to highlight the revisions and reasons for them. Also the PCCP design program was developed and the design program results are compared with the calculations of the GMR project design consultant.

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ACCELERATED CONSTRUCTION OF URBAN INTERSECTIONS WITH PORTLAND CEMENT CONCRETE PAVEMENT (PCCP)

  • Kamran M. Nemati
    • International conference on construction engineering and project management
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    • 2005.10a
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    • pp.886-891
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    • 2005
  • The frequent maintenance required on some asphalt concrete (AC) pavement sections has made reconstruction with Portland Cement Concrete Pavement (PCCP) a feasible alternative. However, many constructability issues need to be addressed in order to realize the full potential of this alternative. Accelerated paving encompasses three classes of activities: methods to accelerate the rate of strength gain, methods to minimize the construction time, and traffic control strategies to minimize user delay. Three major AC intersections with severe rutting problems were reconstructed with PCCP. The entire reconstruction of each intersection, including demolition of the AC pavement and its replacement with PCCP, took place over a period of three days, starting on Thursday evening and opening the intersection to the traffic on Sunday afternoon. This paper discusses the use of PCCP for accelerated reconstruction of major urban intersections with minimal user and traffic disruption, using innovative construction techniques and traffic management optimization principles and demonstrates that concrete pavements can be constructed efficiently and quickly.

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Fabrication and Properties of Organic Semiconductor CuPccp LB Thin Film (유기 반도체 CuPccp LB초박막의 제작 및 특성)

  • Jho, Mean Jea;Xouyang, Saiyang;Lee, Jin Su;Ahn, Da Hyun;Jung, Chi Sup
    • Journal of Sensor Science and Technology
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    • v.28 no.1
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    • pp.23-29
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    • 2019
  • A copper tetracumylphenoxy phthalocyanine (CuPccp) thin film was formed on an organic insulator film by Langmuir-Blodgett (LB) deposition for gas sensor fabrication. To increase the reproducibility of film transfer, stearyl alcohol was used as a transfer promoter. The structural properties of the CuPccp layers were optically monitored through attenuated total reflection and polarization-modulated ellipsometry techniques. The average thickness of a single layer of the CuPccp LB film was measured to be 2.5 nm. Despite the role of the transfer promoter, the stability of the layer transfer was not sufficient to ensure homogeneity of the LB film. This was probably due to the presence of aggregates in the molecular structure of the CuPccp LB film. Nevertheless, copper phthalocyanine polymorphism can be greatly suppressed by the LB arrangement, which appears to contribute to the improvement of electrical conductivity. The p-type semiconductor characteristics were confirmed by Hall measurements from the CuPccp LB films.

PCCP Desing Program using AWWA C304 and Fitting Design Program (AWWA C304를 적용한 PCC관 설계 및 Fitting 설계 전산프로그램)

  • 김영수;김두영;조능호
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.10a
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    • pp.815-822
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    • 1999
  • This program is developed to design Prestressed Concrete Cylinder Pipes (PCCP), Fittings and Thurst Blocks and to manage drawings, quantity calculations and calculation data, using Graphic User Interface(GUI), which is capble of not only reducing the time taken to design, but also enabling the user to achieve such a design even when operator has no theoretical knowledge of that design while only having knowledge of data inputting and outputting. PCCP is used in water transmission popeline of the Great Man-made River Project. In domestic area, PCCP is used for water cooling systems of Uljin and Youngkwang nuclear power. In abroad, especially in the United States and Canada PCCP applies virtually every metropolitan area with raw and treated water.

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Retrofit Design of Damaged Prestressed Concrete Cylinder Pipes

  • Lee, Yongjei;Lee, Eun-Taik
    • International Journal of Concrete Structures and Materials
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    • v.7 no.4
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    • pp.265-271
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    • 2013
  • Prestressed concrete cylindrical pipe (PCCP) has been widely used for the distribution of water in communal, industrial, and agricultural systems for a long time. However, as it deteriorates, structural failures have been experienced. Replacing the entire existing PCCP with partial damages is not an economical method. Currently, as a cost effective repairing method, a new approach using fiber reinforced polymer (FRP) has been applied. A new design procedure of this method was proposed considering various kinds of loading condition. However, it is not easy to apply this method for design purpose due to its complex procedures. The objective of this study is to provide a new design criteria and process for PCCP rehabilitation with FRP. Through this method, the appropriate quantities of FRP layers will be decided after examining of limit states of deteriorated PCCP. For this purpose, two deterioration conditions are assumed; fully deteriorated and partially deteriorated. Different limit states for each case are applied to decide the quantities of attached FRP. The concept of "margin of safety" is used to judge whether the design results are within the optimal ranges to satisfy all limit states.

Proactive Consultation by a Clinical Pathologist Prevents Diagnostic Delay in Hematological Malignancies

  • Chang, Chih-Chun;Su, Ming-Jang;Ho, Jung-Li;Sun, Jen-Tang;Tsai, Huang-Wen;Tang, Hui-Fei;Chu, Fang-Yeh
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.3
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    • pp.1019-1022
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    • 2016
  • Background: Diagnostic difficulties in hematological malignancies may lead to unacceptably prolonged help-seeking to diagnostic interval as well as increased complications and poor outcomes. Proactive consultation by a clinical pathologist (PCCP) may help clinical diagnosis and therapeutic strategy. Hence, the aim of this investigation was to evaluate the effect of PCCP on the help-seeking to diagnostic interval in hematological cancer cases. Materials and Methods: From January to November, 2015, abnormal results of hematological laboratory testing with added laboratory comment were selectively screened out, and patients with such abnormalities in hematological laboratory testing and accompanied laboratory comment with PCCP were enrolled. Results: A total of 125 aberrant results of hematological laboratory testing were given with accompanied laboratory comments with PCCP and 40.8% (n=51) of these patient-oriented comments had an effect on clinical diagnosis and therapeutic strategy. Twelve of the subjects belonged to newly diagnosed hematological malignancies with the assistance of PCCP, and the help-seeking to diagnostic interval was also shortened from 42 days to 26 days in chronic lymphoid leukemia (CLL), from 83 days to 11 days in multiple myeloma (MM), and from 128 days to 15 days in myelodysplastic syndrome/myeloproliferative neoplasm (MDS/MPN). During the monitoring interval, neither complication events nor deaths were reported in the study group. Conclusions: It was seemingly that PCCP prevented diagnostic delay in hematological malignancies via shortening the help-seeking to diagnostic interval, particularly in CLL, MM and MDS/MPN cases. PCCP can be considered to play an essential role in prompt establishment of diagnosis in hematological malignancies for those who newly present.

Effect of RuCl3 Concentration on the Lifespan of Insoluble Anode for Cathodic Protection on PCCP

  • Cho, H.W.;Chang, H.Y.;Lim, B.T.;Park, H.B.;Kim, Y.S.
    • Corrosion Science and Technology
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    • v.14 no.4
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    • pp.177-183
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    • 2015
  • Prestressed Concrete steel Cylinder Pipe (PCCP) is extensively used as seawater pipes for cooling in nuclear power plants. The internal surface of PCCP is exposed to seawater, while the external surface is in direct contact with underground soil. Therefore, materials and strategies that would reduce the corrosion of its cylindrical steel body and external steel wiring need to be employed. To prevent against the failure of PCCP, operators provided a cathodic protection to the pre-stressing wires. The efficiency of cathodic protection is governed by the anodic performance of the system. A mixed metal oxide (MMO) electrode was developed to meet criteria of low over potential and high corrosion resistance. Increasing coating cycles improved the performance of the anode, but cycling should be minimized due to high materials cost. In this work, the effects of $RuCl_3$ concentration on the electrochemical properties and lifespan of MMO anode were evaluated. With increasing concentration of $RuCl_3$, the oxygen evolution potential lowered and polarization resistance were also reduced but demonstrated an increase in passive current density and oxygen evolution current density. To improve the electrochemical properties of the MMO anode, $RuCl_3$ concentration was increased. As a result, the number of required coating cycles were reduced substantially and the MMO anode achieved an excellent lifespan of over 80 years. Thus, we concluded that the relationship between $RuCl_3$ concentration and coating cycles can be summarized as follows: No. of coating cycle = 0.48*[$RuCl_3$ concentration, $M]^{-0.97}$.

Butt-fusing Procedures and Qualifications of High Density Polyethylene Pipe for Nuclear Power Plant Application (원자력발전소 적용 고밀도 폴리에틸렌 배관의 맞대기 융착절차 및 검증절차 분석)

  • Oh, Young-Jin;Park, Heung-Bae;Shin, Ho-Sang
    • Journal of Welding and Joining
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    • v.31 no.6
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    • pp.1-7
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    • 2013
  • In nuclear power plants, lined carbon steel pipes or PCCPs (pre-stressed concrete cylinder pipes) have been widely used for sea water transport systems. However, de-bonding of linings and oxidation of PCCP could make problems in aged NPPs (nuclear power plants). Recently at several NPPs in the United States, the PCCPs or lined carbon steel pipes of the sea water or raw water system have been replaced with HDPE (high density polyethylene) pipes, which have outstanding resistance to oxidation and seismic loading. ASME B&PV Code committee developed Code Case N-755, which describes rules for the construction of buried Safety Class 3 polyethylene pressure piping systems. Although US NRC permitted HDPE materials for Class 3 buried piping, their permission was limited to only 10-year operation because of several concerns including the quality of fusion zone of HDPE. In this study, various requirements for fusion qualification test of HDPE and some regulatory issues raised during HDPE application review in foreign NPPs are introduced.