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Full-Text Articles in Engineering

Mathematical Modeling And Prediction Method Of Concrete Carbonation And Its Applications, Ming Te Liang, Wenjun Qu, Chih-Hsin Liang Dec 2002

Mathematical Modeling And Prediction Method Of Concrete Carbonation And Its Applications, Ming Te Liang, Wenjun Qu, Chih-Hsin Liang

Journal of Marine Science and Technology

The carbonation process of concrete is principally a diffusion phenomenon. The penetration rate of carbon dioxide depends mainly on the concrete quality and the exposure condition. Based on both Fick’s first and second laws of linear diffusion equations, the threedimensional equation of conservation of mass is expressed. This equation can be reduced to two- and one- dimensional equations of conservation of mass which can predict the carbonation depth beneath corners and the general surface of concrete structures, respectively. The objectives of this investigation are to measure the depth of carbonation from the free surface of a concrete member and to …


Effect Of Dissolved Oxygen On The Corrosion Behavior Of Coalesced Copper And Stainless Steel-206 In Acetic Solutions, Rong-Zong Hu, Xiong-Cao Zhao, Yu-Hua Weng, Chang-Jian Lin Nov 2002

Effect Of Dissolved Oxygen On The Corrosion Behavior Of Coalesced Copper And Stainless Steel-206 In Acetic Solutions, Rong-Zong Hu, Xiong-Cao Zhao, Yu-Hua Weng, Chang-Jian Lin

Journal of Electrochemistry

Linear sweeping technique and dissolving oxygen sensor were used to study the effect of dissolved oxygen and relating factors on the corrosion behavior of coalesced copper and stainless steel-206 in acetic solutions. It was found: 1. The existing of dissolved oxygen is one of the important factors, which strongly influenced the corrosion behavior of coalesced copper and stainless steel-206 in acetic solution. 2. The existing of dissolved oxygen is benefitial to the preventing stainless steel-206 from corrosion in acetic solutions, but damage to the preventing coalesced copper from corrosion. 3. At the high temperature since the dissolved oxygen was escaping …


Electrochemical Techniques For Measuring Anti-Corrosion Behavior Of The Thin Corrosion Inhibitor Layer To The 907a Steel, Yong-Tao Zhao, Jian-Hua Wu, Fan-Cai Chen, Zhong-Ping Gao, Jia Wang, Chang-Jiu Zhao Aug 2002

Electrochemical Techniques For Measuring Anti-Corrosion Behavior Of The Thin Corrosion Inhibitor Layer To The 907a Steel, Yong-Tao Zhao, Jian-Hua Wu, Fan-Cai Chen, Zhong-Ping Gao, Jia Wang, Chang-Jiu Zhao

Journal of Electrochemistry

The corrosion inhibiting behavior of 907A steel,which was covered with thin inhibitor layers in moist seawater atmosphere,was studied.The electrochemical measurements,including EIS method and the coulostatic method,were used to atmospheric corrosioed monitor(ACM)under thin inhibitor layers to determine its corrosion rate.The results shown that the application of electrochemical methods such as the coulostatic technique and EIS could readily detect the on going process of film formation. Hence, the rapid evaluation of the thin inhibitor layers for 907A steel might be possible.


Corrosive Electrochemical Behavior Of Carbon Steel In Microbiological Medium, Jing Liu, Hong-Bo Fan, Hai-Ping Xu, Jia-Shen Zheng, Li-Ming Xu, Zong-Qiang Mao May 2002

Corrosive Electrochemical Behavior Of Carbon Steel In Microbiological Medium, Jing Liu, Hong-Bo Fan, Hai-Ping Xu, Jia-Shen Zheng, Li-Ming Xu, Zong-Qiang Mao

Journal of Electrochemistry

Sulfate_reducing bacteria(SRB)grows and propagates, PH of the solution is dropped from 7.5 to 5.8,and forms the biofilms on carbon steel in culture medium.The micro_environment on the surface of carbon steel is changed under the biofilms,the factors accelerate the formation of the pitting corrosion. When the biofilm on carbon steel is cleaned out,the surface of carbon steel have the non_uniform pitting corrosion. The activity of SRB and the porous structure of biofilms induced the initiation and development of the pitting corrosion of carbon steel.The process of microbiologically induced corrosion(MIC) involves the development of SRB activity,which promotes the permeation of gydrogen into …


Performance-Related Specifications For Concrete Bridge Superstructures, Volume 1: Performance Parameters And Related Procedure For Concrete Bridge Superstructures, J. A. Ramirez, Jhon Paul Smith Jan 2002

Performance-Related Specifications For Concrete Bridge Superstructures, Volume 1: Performance Parameters And Related Procedure For Concrete Bridge Superstructures, J. A. Ramirez, Jhon Paul Smith

JTRP Technical Reports

In Volume 1 of the final report, the identification of performance levels and parameters, and the development of acceptance criteria, have been addressed. Emphasis has been placed on the development of a methodology for a Performance Related Specification, PRS, for concrete bridge superstructures. The implementation of the methodology, presented in the form of a user-friendly computer program, is project specific. It requires the mean and standard deviation (or definition of a probability distribution) of the input parameters for the performance predictive models. This is done for both the as-designed condition and the as-built condition of the structure. The contractor is …


Performance-Related Specifications For Concrete Bridge Superstructures, Volume 4: Bond Of Epoxy-Coated Bars With Thicker Coatings, J. A. Ramirez, Michael K. Appelhans Jan 2002

Performance-Related Specifications For Concrete Bridge Superstructures, Volume 4: Bond Of Epoxy-Coated Bars With Thicker Coatings, J. A. Ramirez, Michael K. Appelhans

JTRP Technical Reports

In Volume 4 of the final report, the results of an evaluation of the bond performance of epoxy-coated bars with a coating thickness up to 18 mils are presented. The experimental work on the bond performance of epoxy-coated bars with thickness up to 18 mils indicates that the current AASHTO requirements for development length of epoxy-coated bars up to #8 could be safely extended to coating thickness of up to 18 mils. Thus, no change to the bond specifications is recommended in order to implement the use of bars with diameters up to a #8 with epoxy-coating thickness up to …


Performance-Related Specifications For Concrete Bridge Superstructures, Volume 3: Nonmetallic Reinforcement, Robert J. Frosch, Christopher P. Mosley, Ahmet Koray Tureyen Jan 2002

Performance-Related Specifications For Concrete Bridge Superstructures, Volume 3: Nonmetallic Reinforcement, Robert J. Frosch, Christopher P. Mosley, Ahmet Koray Tureyen

JTRP Technical Reports

In Volume 3 of the final report, research work conducted to investigate the behavior of fiber reinforced polymer (FRP) reinforcement is summarized. This study focused on the behavior of FRP reinforced concrete structures with an emphasis on bond and shear. For the bond investigation, three series of beam splice tests were performed on specimens reinforced with steel, glass FRP, and aramid FRP to determine the effect of the different types of reinforcement on bond, cracking, and deflections. The test results indicate that the use of FRP reinforcement leads to lower bond strengths and, therefore, require longer development lengths. The specimen …