Download or read book Corrosion Behavior of Galvanized Steel Reinforcements in MSE Walls in the Presence of Soil Organics written by Claudia Aide Soriano Vazquez and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Long Term Corrosion of Reinforcing Strips in Mechanically Stabilized Earth Walls written by Brandon Seth Berke and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: Mechanically stabilized earth (MSE) walls are a more advanced form of a retaining wall, often larger and able to hold back more backfill. This is achieved by reinforcing strips or meshes (most often galvanized steel) placed into the soil, which are held in place by friction. The strips mechanically stabilize the earth while undergoing tension. The wall is covered with concrete medallions that connect to the reinforcements. The medallions have only a secondary structural role in holding up the wall but provide cover that protects the soil from washing away. MSE walls are structures expected to have very long service lives (e.g. 100 years). Confirmation is needed that such durability can be achieved, especially to show that the progression of corrosion of the reinforcement is slow enough. Ten MSE walls around Florida were instrumented (electrical connections were made through the concrete covers to the buried elements) between 1996- 1998 and used to survey corrosion rates of galvanized strip or mesh soil reinforcements. Initial estimates of corrosion-related durability were obtained at that time, indicating a good prognosis for long term durability. The objective of the research in this thesis was to obtain additional indications of the durability of reinforcements in MSE walls in Florida so as to perform a more reliable projection of future performance. Corrosion behavior was measured at the same locations as the initial survey by electrochemical nondestructive tests and by destructive tests. The nondestructive testing consisted of half-cell potentials, polarization resistance measurements, and electrochemical impedance spectroscopy. Corrosion rates reported in this thesis are based upon polarization resistance measurements. The destructive testing consisted of soil extraction and hardware extraction. Hardware extraction enabled independent verification of estimates of electrochemical corrosion rate. Analysis of extracted soil verified that soil composition was within construction specifications. The data from the current survey were also used to further improve prediction of corrosion. The present series of evaluations confirm that the structures are performing as desired based upon the updated model projection of future corrosion.
Download or read book Corrosion of Steel in MSE Walls Due to Deicers and Backfill Aggregates written by Dipesh Tajhya and published by . This book was released on 2017 with total page 570 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mechanically Stabilized Earth (MSE) wall is a civil structure that has been used for various purposes e.g., supporting bridges, residential or commercial buildings, roadways, railroads etc. In general, MSE wall uses either metal strip, bar or geosynthetics materials as reinforcement. Roger et al. (2010) mentioned that an approximately 57% of the MSE wall constructed in U.S. utilize steel strips as the resources of reinforcement. The usage of metal steel strips is followed by usage of steel bar mats (24%) and geosynthetics grids (18%). Even though MSE walls are designed for a service life of 75 to 100 years, early complication has often been reported. Corrosion of the reinforced steel has been the major cause that afflicts the long-term performance of these walls. The deicing salts used on pavements to melt down snow is one of the major cause of corrosion of these reinforced steels. The aggressiveness of deicers in terms of corrosion of these reinforced steel is studied through the potentiodynamic polarization technique at various concentrations. This study aims to determine the corrosion behavior on galvanized steel and bare steel in presence of individual deicing salt or deicers e.g., sodium chloride, calcium chloride, magnesium chloride and potassium acetate at various (i.e., 0.25, 0.50 and 1.0 M) concentration. Subsequently, the surface morphology was analyzed by using Scanning Electron Microscopy (SEM) and the mineralogical composition was observed through X-Ray Diffraction (XRD). In addition, the corrosivity of two backfill aggregates, natural aggregate and recycled concrete aggregate, was compared. The result shows that the corrosion effect of deicers on reinforced steel depends on its chemical composition and concentration. The SEM imaging showed the presence of micro cracks on the surface of galvanized steel, resulting in pitting corrosion rather than general surficial corrosion. Comparing the corrosion rate of these deicers, the aggressiveness of these deicers on galvanized steel can be arranged in the following order: sodium chloride > calcium chloride > magnesium chloride > potassium acetate. Although sodium chloride was most aggressive for both the steel, the aggressiveness of these deicers on bare steel was different from that of galvanized steel and can be arranged in following order: sodium chloride > magnesium chloride > calcium chloride > potassium acetate. The pH and electrical resistivity of the natural and recycled aggregates were compared with standard provided by American Association of State Highway and Transportation Officials (AASHTO) and found to be non-corrosive. The corrosion rate of both the aggregates on galvanized and bare steel were inappreciable. While analyzing the corrosiveness of these two aggregates, recycled concrete aggregate was observed to be more aggressive than the natural aggregate.
Download or read book Corrosion Effects of Cement Stabilized Backfill on Galvanized Steel Earth Reinforcements written by Derek V. Morris and published by . This book was released on 1994 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cement stabilization of backfill has been used for some time in mechanically stabilized earth type retaining walls. However, there has been no data on the corrosion life of galvanized steel reinforcement in this environment, which is intermediate in pH between normal soil and pure cement. Field observations had indicated a potential corrosion problem at a particular site in District 12. As a result of the test program conducted during this project, the following conclusions were made. First, cement addition to backfill in the usual quantities (i.e. 7% or more) raised the pH environment to values close to that of normal concrete. At these levels corrosion rates of zinc coatings were not significantly accelerated -- if anything, corrosion rates were less than for unstabilized fill. Second, very small amounts of cement addition, of the order of 1% to 4% producing pH values significantly less than 12, could cause limited acceleration of corrosion. It is, therefore, advisable to control minimum cement levels and to encourage efficient mixing. Third, elevated corrosion rates were associated primarily with the presence of inorganic ions, both for stabilized and unstabilized fill. In the case of the problem site in District 12, this appeared to be the result primarily of unusually high sulfate content in the fill. Fourth, the use of crushed concrete as backfill did not accelerate corrosion. This material, therefore, appears to be acceptable for this application.
Download or read book The Corrosion Behavior of Galvanized Steel in Mechanically Stabilized Earth Wall Structures written by Juan Pedro Rossi and published by . This book was released on 1996 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Assessment of In situ Corrosion Conditions at Nevada Mechanically Stabilized Earth Wall Sites written by Nelson Pearson and published by . This book was released on 2015 with total page 572 pages. Available in PDF, EPUB and Kindle. Book excerpt: The inability of soil to provide sufficient tensile strength presents challenges for soils being used as a structural building material. However, it is possible to improve the structural performance with the inclusion of a reinforcing system. The development of these systems has been a major advancement of the civil engineering practice. Mechanically stabilized earth (MSE) wall systems typically consist of a: concrete facing panel, specified backfill, reinforcing elements, and the retained fill. The interaction of the backfill with the reinforcements, and the reinforcements with the facing panels, produces a system that when properly designed, can be a cost effective engineering solution. In Nevada there are over 150 MSE walls that have been constructed using metallic reinforcements (Thornley 2009). Corrosion of metallic elements a naturally occurring electrochemical process is irreversible an inevitable. The rate of metal loss (corrosion) is a function of the environmental conditions and metal type. For MSE walls key parameters include the backfill's: salt content, organic content, saturation level, as well as the metal type of the reinforcements. Nevada has two previous corrosion investigations, an extensive site investigation at I-515/ Flamingo Rd. and a statistical analysis of as-built soil records along with a preliminary investigation for I-15/ Cheyenne Blvd. These studies form the foundation for this investigation of in-situ corrosion conditions. Seven MSE wall sites were investigated using electrochemical backfill characterization and linear polarization resistance (LPR) corrosion rate monitoring. Evaluation of electrochemical backfill characteristics has resulted in the discovery of six sites that fail current NDOT/ AASHTO MSE wall backfill requirements. The in-situ soil samples collected and analyzed more than doubled the available data used to describe the corrosiveness of the backfill. Linear polarization resistance corrosion rates were obtained for more than 200 different elements. These data suggest that despite the aggressive nature of the backfill, most elements are preforming well and are below the anticipated rates. However, several elements were discovered with corrosion rates in excess of five times the design model. The use of the LPR corrosion monitoring has concluded that the conditions at I-15/ and Cheyenne Blvd. are equivalent to or worse than the conditions evaluated in 2004 at the I-515/ Flamingo Rd. complex. The discoveries at Flamingo Rd. led to remediation of the largest wall at the complex. Through the use of electrochemical backfill characteristics and LPR corrosion rates, the seven sites investigated have been ranked. The rankings are dependent on several factors such as backfill electrochemical conditions and comparison of corrosion rates data with design models. This study has confirmed that observations of conditions along the exterior of the wall are not sufficient when determining the condition of the soil reinforcements. Routine corrosion monitoring is required to monitor the depletion of the soil reinforcements and should be incorporated into a Long-term Corrosion Monitoring and Asset Management Plan (LCMAMP). It is anticipated that a program will be integrated into Nevada's current asset management systems. The development and implementation of LCMAMP, directly reflects the federal initiative for systematic detailed evaluation of critical assets, MAP-21.
Download or read book Corrosion and Surface Chemistry of Metals written by Dieter Landolt and published by EPFL Press. This book was released on 2007-05-02 with total page 640 pages. Available in PDF, EPUB and Kindle. Book excerpt: Textbook; grad.
Download or read book Underground Corrosion written by Melvin Romanoff and published by N A C E International. This book was released on 1989 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Soil Improvement and Ground Modification Methods written by Peter G. Nicholson and published by Butterworth-Heinemann. This book was released on 2014-08-29 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by an author with more than 25 years of field and academic experience, Soil Improvement and Ground Modification Methods explains ground improvement technologies for converting marginal soil into soil that will support all types of structures. Soil improvement is the alteration of any property of a soil to improve its engineering performance. Some sort of soil improvement must happen on every construction site. This combined with rapid urbanization and the industrial growth presents a huge dilemma to providing a solid structure at a competitive price. The perfect guide for new or practicing engineers, this reference covers projects involving soil stabilization and soil admixtures, including utilization of industrial waste and by-products, commercially available soil admixtures, conventional soil improvement techniques, and state-of-the-art testing methods. Conventional soil improvement techniques and state-of-the-art testing methods Methods for mitigating or removing the risk of liquefaction in the event of major vibrations Structural elements for stabilization of new or existing construction industrial waste/by-products, commercially available soil Innovative techniques for drainage, filtration, dewatering, stabilization of waste, and contaminant control and removal
Download or read book Earth Pressure and Earth Retaining Structures Third Edition written by Chris R.I. Clayton and published by CRC Press. This book was released on 2014-05-28 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt: Effectively Calculate the Pressures of Soil When it comes to designing and constructing retaining structures that are safe and durable, understanding the interaction between soil and structure is at the foundation of it all. Laying down the groundwork for the non-specialists looking to gain an understanding of the background and issues surrounding geotechnical engineering, Earth Pressure and Earth-Retaining Structures, Third Edition introduces the mechanisms of earth pressure, and explains the design requirements for retaining structures. This text makes clear the uncertainty of parameter and partial factor issues that underpin recent codes. It then goes on to explain the principles of the geotechnical design of gravity walls, embedded walls, and composite structures. What’s New in the Third Edition: The first half of the book brings together and describes possible interactions between the ground and a retaining wall. It also includes materials that factor in available software packages dealing with seepage and slope instability, therefore providing a greater understanding of design issues and allowing readers to readily check computer output. The second part of the book begins by describing the background of Eurocode 7, and ends with detailed information about gravity walls, embedded walls, and composite walls. It also includes recent material on propped and braced excavations as well as work on soil nailing, anchored walls, and cofferdams. Previous chapters on the development of earth pressure theory and on graphical techniques have been moved to an appendix. Earth Pressure and Earth-Retaining Structures, Third Edition is written for practicing geotechnical, civil, and structural engineers and forms a reference for engineering geologists, geotechnical researchers, and undergraduate civil engineering students.
Download or read book Applied Metallurgy and Corrosion Control written by Amiya Kumar Lahiri and published by Springer. This book was released on 2017-08-23 with total page 558 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book serves as a comprehensive resource on metals and materials selection for the petrochemical industrial sector. The petrochemical industry involves large scale investments, and to maintain profitability the plants are to be operated with minimum downtime and failure of equipment, which can also cause safety hazards. To achieve this objective proper selection of materials, corrosion control, and good engineering practices must be followed in both the design and the operation of plants. Engineers and professional of different disciplines involved in these activities are required to have some basic understanding of metallurgy and corrosion. This book is written with the objective of servings as a one-stop shop for these engineering professionals. The book first covers different metallic materials and their properties, metal forming processes, welding, and corrosion and corrosion control measures. This is followed by considerations in material selection and corrosion control in three major industrial sectors, oil & gas production, oil refinery, and fertilizers. The importance of pressure vessel codes as well as inspection and maintenance repair practices have also been highlighted. The book will be useful for technicians and entry level engineers in these industrial sectors. Additionally, the book may also be used as primary or secondary reading for graduate and professional coursework.
Download or read book Characterization of Minerals Metals and Materials 2019 written by Bowen Li and published by Springer. This book was released on 2019-02-13 with total page 804 pages. Available in PDF, EPUB and Kindle. Book excerpt: This collection gives broad and up-to-date results in the research and development of materials characterization and processing. Topics covered include characterization methods, ferrous materials, non-ferrous materials, minerals, ceramics, polymer and composites, powders, extraction, microstructure, mechanical behavior, processing, corrosion, welding, solidification, magnetic, electronic, environmental, nano-materials, and advanced materials The book explores scientific processes to characterize materials using modern technologies, and focuses on the interrelationships and interdependence among processing, structure, properties, and performance of materials.
Download or read book Electrochemical Test Methods to Evaluate the Corrosion Potential of Earthen Materials written by Kenneth L. Fishman and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electrochemical properties of earthen materials such as electrical resistivity, pH, salt concentrations, and organic contents are commonly used to characterize the corrosion potential of buried metal elements that are in direct contact with the surrounding soil. The TRB National Cooperative Highway Research Program's NCHRP Research Report 958: Improved Test Methods and Practices for Characterizing Steel Corrosion Potential of Earthen Materials proposes a protocol describing best practices for sampling, testing, and characterizing the steel corrosion potential of earthen materials. The protocol incorporates alternatives to the current AASHTO test standards for measuring electrochemical properties.
Download or read book Karst Management written by Philip E. van Beynen and published by Springer Science & Business Media. This book was released on 2011-06-21 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt: Focusing specifically on the management of karst environments, this volume draws together the world’s leading karst experts to provide a vital source for the study and management of this unique physical setting. Although karst landscapes cover 12% of the Earth’s terrain and provide 25% of the world’s drinking water, the resource management of karst environments has only previously received indirect attention. Through a comprehensive approach, Karst Management focuses on engineering issues associated with surface karst such as quarries, dams, and agriculture, subsurface topics such as the management of groundwater, show caves, cave biota, and geo-archaeology projects. Chapters that focus on karst as an integrated system look at IUCN World Heritage sites, national parks, policy and regulation, measuring systematic disturbance, information management, and public environmental education. The text incorporates the most up-to-date research from leading karst scientists. This volume provides important perspectives for university students, educators, geoengineers, resource managers, and planners who are interested in or work with this unique physical landscape.
Download or read book Foundations Earth Structures written by and published by . This book was released on 1986 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Performance Based Specifications and Control of Concrete Durability written by Hans Beushausen and published by Springer. This book was released on 2015-09-24 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work gives an overview of significant research from recent years concerning performance-based design and quality control for concrete durability and its implementation. In engineering practice, performance approaches are often still used in combination with prescriptive requirements. This is largely because, for most durability test methods, sufficient practical experience still has to be gained before engineers and owners are prepared to fully rely on them. This book, compiled by RILEM TC 230-PSC, is intended to assist efforts to successfully build the foundation for the full implementation of performance-based approaches through the exchange of relevant knowledge and experience between researchers and practitioners worldwide.
Download or read book Proceedings of AICCE 19 written by Fadzli Mohamed Nazri and published by Springer Nature. This book was released on 2019-11-28 with total page 1635 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gathers the latest research, innovations, and applications in the field of civil engineering, as presented by leading national and international academics, researchers, engineers, and postgraduate students at the AWAM International Conference on Civil Engineering 2019 (AICCE’19), held in Penang, Malaysia on August 21-22, 2019. The book covers highly diverse topics in the main fields of civil engineering, including structural and earthquake engineering, environmental engineering, geotechnical engineering, highway and transportation engineering, water resources engineering, and geomatic and construction management. In line with the conference theme, “Transforming the Nation for a Sustainable Tomorrow”, which relates to the United Nations’ 17 Global Goals for Sustainable Development, it highlights important elements in the planning and development stages to establish design standards beneficial to the environment and its surroundings. The contributions introduce numerous exciting ideas that spur novel research directions and foster multidisciplinary collaborations between various specialists in the field of civil engineering.
