Download or read book Continued Monitoring of the Varina Enon Bridge Estimation of Effective Prestress written by Seth Lindley and published by . This book was released on 2022 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt: Prestress loss due to creep, shrinkage, and relaxation can cause serviceability issues, and in the case of structures post-tensioned with unbonded tendons, can reduce the flexural capacity. The accurate estimation of prestress losses is vital for making good decisions about the remaining life of a structure. The Varina-Enon Bridge is a post-tensioned concrete box-girder bridge near Richmond, Virginia. Flexural cracks in the bridge prompted an investigation into the magnitude of prestress loss experienced by the structure. Long-term prestress losses were estimated using two methods. First, a finite element model was created, and multiple code expressions for creep and shrinkage were applied to a time-step analysis of the structure. The code expressions investigated in this research were from the CEB-FIP 1978, CEB-FIP 1990, CEB-FIP 2010, and AASHTO (2017) codes. The second method utilized data from sensors installed on the bridge to back-calculate the effective prestressing force based on recorded openings of the flexural cracks. For the four spans monitored in this research, the field-determined effective prestress varied between 161 ksi and 166 ksi. Using the commercially available bridge design software, LARSA 4D, along with the creep and shrinkage model used in the original design, CEB-FIP 1978, the calculated effective prestress varied between 169 ksi and 171 ksi. This indicates that prestress losses were higher than anticipated in the original design, but the measured effective prestress was still, on average, about 96% of the design effective prestress. The more modern creep and shrinkage models of CEB-FIP 1990 and CEB-FIP 2010 also predicted higher than measured effective prestress, with both being very similar to CEB-FIP 1978. The effective prestress predicted by the AASHTO (2017) model was slightly higher. Calculation of flexural capacity using the effective prestress estimated by the field measurement system resulted in estimates of strength 1 to 4% smaller than using the effective prestress estimated by the original creep and shrinkage model used for design. Measured thermal gradients over the period studied in this project were smaller than the AASHTO LRFD design gradients; however, the restraint moment calculated for the worst case measured gradient was very similar to the restraint moment calculated using the design gradient.
Download or read book Research Technology Transporter written by and published by . This book was released on 1998 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Highway Research Abstracts written by and published by . This book was released on 1994 with total page 1006 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Durability of Post tensioning Tendons written by fib Fédération internationale du béton and published by fib Fédération internationale du béton. This book was released on 2006 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: The durability of post-tensioning tendons depends undoubtedly on the durability of the materials used, but there are design concept specifics which are also of major importance: the post-tensioning layout and layers of protection such as concrete cover and selected materials in view of the aggressivity of the environment for instance. It is well known that sustainability principles guide the Engineer from the very beginning, at the project conception, during construction and the service life of a structure. Decisions made during conceptual and design stage have the largest influence on the durability and sustainability of post-tensioning tendons. fibBulletin 33 addresses the specifics for prestressed concrete structures: the durability of post-tensioning tendons. It should be noted that it does not repeat topics that have been addressed in other fib bulletins and which is common for both reinforced concrete and prestressed concrete structures. Pre-tensioning, which is used extensively in the precast industry, is not considered here, although conclusions and recommendations herein may, in many cases, also be applicable. This recommendation was prepared by Working Party 5.4.2, Durability specifics for prestressed concrete structures, in cooperation with fib Commission 9,Reinforcing and prestressing materials and systems. A preliminary version of this recommendation served as the basic document for the second workshop on "Durability of post-tensioning tendons", held on 11-12 October 2004 in Zurich. This workshop was a follow-up to the first workshop held in Ghent in 2001. Bulletin 33 includes revisions corresponding to the agreed results of the Zurich workshop.
Download or read book Specification for Grouting of Post tensioned Structures written by and published by . This book was released on 2020 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This specification provides minimum requirements for the selection, design, and installation of cementitious grouts for steel post-tensioned systems used in concrete construction. The purpose of the grout is to provide corrosion protection to the prestressing steel and in bonded post-tensioning (PT) applications to develop bond between the prestressing steel and the surrounding concrete." -- From publisher
Download or read book Steel Bridges written by Manfred Hirt and published by CRC Press. This book was released on 2013-06-05 with total page 569 pages. Available in PDF, EPUB and Kindle. Book excerpt: This English translation of the successful French edition presents the conception and design of steel and steel-concrete composite bridges, from simple beam bridges to cable supported structures. The book focuses primarily on road bridges, emphasizing the basis of their conception and the fundamentals that must be considered to assure structural safety and serviceability, as well as highlighting the necessary design checks. The principles are extended in later chapters to railway bridges as well as bridges for pedestrians and cyclists. Particular attention is paid to consideration of the dynamic performance.
Download or read book Corrosion of Steel in Concrete Structures written by Amir Poursaee and published by Woodhead Publishing. This book was released on 2023-02-20 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: Essential reading for researchers, practitioners, and engineers, this book covers not only all the important aspects in the field of corrosion of steel reinforced concrete but also discusses new topics and future trends. Theoretical concepts of corrosion of steel in concrete structures, the variety of reinforcing materials and concrete, including stainless steel and galvanized steel, measurements and evaluations, such as electrochemical techniques and acoustic emission, protection and maintenance methods, and modelling, latest developments, and future trends in the field are discussed. Comprehensive coverage of the corrosion of steel bars in concrete, investigating the range of reinforcing materials, and types of concrete Introduces the latest measuring methods, data collection, and advanced modeling techniques Second edition covers a range of new, emerging topics such as the concept of chloride threshold value, concrete permeability and chloride diffusion, the role of steel microstructure, and innovations in corrosion detection devices
Download or read book Prestressed Concrete Bridges written by Nigel R. Hewson and published by Thomas Telford. This book was released on 2003 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt: Prestressed concrete decks are commonly used for bridges with spans between 25m and 450m and provide economic, durable and aesthetic solutions in most situations where bridges are needed. Concrete remains the most common material for bridge construction around the world, and prestressed concrete is frequently the material of choice. Extensively illustrated throughout, this invaluable book brings together all aspects of designing prestressed concrete bridge decks into one comprehensive volume. The book clearly explains the principles behind both the design and construction of prestressed concrete bridges, illustrating the interaction between the two. It covers all the different types of deck arrangement and the construction techniques used, ranging from in-situ slabs and precast beams; segmental construction and launched bridges; and cable-stayed structures. Included throughout the book are many examples of the different types of prestressed concrete decks used, with the design aspects of each discussed along with the general analysis and design process. Detailed descriptions of the prestressing components and systems used are also included. Prestressed Concrete Bridges is an essential reference book for both the experienced engineer and graduate who want to learn more about the subject.
Download or read book Highway Bridges and Culverts written by B. K. Coghlan and published by . This book was released on 1915 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reliability of Structures Second Edition written by Andrzej S. Nowak and published by CRC Press. This book was released on 2012-12-20 with total page 411 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reliability of Structures enables both students and practising engineers to appreciate how to value and handle reliability as an important dimension of structural design. It discusses the concepts of limit states and limit state functions, and presents methodologies for calculating reliability indices and calibrating partial safety factors. It also supplies information on the probability distributions and parameters used to characterize both applied loads and member resistances. This revised and extended second edition contains more discussions of US and international codes and the issues underlying their development. There is significant revision and expansion of the discussion on Monte Carlo simulation, along with more examples. The book serves as a textbook for a one-semester course for advanced undergraduates or graduate students, or as a reference and guide to consulting structural engineers. Its emphasis is on the practical applications of structural reliability theory rather than the theory itself. Consequently, probability theory is treated as a tool, and enough is given to show the novice reader how to calculate reliability. Some background in structural engineering and structural mechanics is assumed. A solutions manual is available upon qualifying course adoption.
Download or read book The Pier End written by Jane V King and published by Balboa Press. This book was released on 2020-11-04 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Pier End is a play designed for performance by a community of players. It was commissioned to allow a group of people to come together, to display their talents and to entertain. It is set at ‘the other end of the pier’, on the edge of a small town beset with troubles. It explores timeless, universal themes such as the power of love and family, but is firmly in the present to relate to the modern day concerns of the cast and audience. Song and dance can be incorporated based on the talent of the ensemble, and five original songs are included. The hero, Jack, is effectively ‘an orphan’, although both parents are still alive in unknown locations. Jack acts as a mentor and supporter in his community, but when he is on his own he has dark thoughts about his lack of kinship. He tries to fill the void by dating three girls simultaneously, and he dislikes himself for his faithlessness. The play has been likened to a 21st century version of a medieval mystery play, and has an upbeat rtesolution when he discovers that one of his ladies is carrying his child, His mother has also mananged to track him doen, so he is joyful at the end of the play The community unite in their concerns for their town and they celebrate resolution and a bright future.
Download or read book Catalog of Copyright Entries Third Series written by Library of Congress. Copyright Office and published by Copyright Office, Library of Congress. This book was released on 1975 with total page 1760 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cambridge International AS A Level Further Mathematics Coursebook written by Lee Mckelvey and published by Cambridge University Press. This book was released on 2018-08-31 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cambridge International AS & A Level Further Mathematics supports students following the 9231 syllabus. This single coursebook comprehensively covers all four modules of the syllabus and helps support students in their studies and develops their mathematical skills. Authored by experienced teachers of Further Mathematics, the coursebook provides detailed explanations and clear worked examples with practice exercises and exam-style questions. Answers are at the back of the book.
Download or read book Community Impact Assessment written by and published by . This book was released on 1996 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: This guide was written as a quick primer for transportation professionals and analysts who assess the impacts of proposed transportation actions on communities. It outlines the community impact assessment process, highlights critical areas that must be examined, identifies basic tools and information sources, and stimulates the thought-process related to individual projects. In the past, the consequences of transportation investments on communities have often been ignored or introduced near the end of a planning process, reducing them to reactive considerations at best. The goals of this primer are to increase awareness of the effects of transportation actions on the human environment and emphasize that community impacts deserve serious attention in project planning and development-attention comparable to that given the natural environment. Finally, this guide is intended to provide some tips for facilitating public involvement in the decision making process.
Download or read book Concrete Structures written by A. Ghali and published by CRC Press. This book was released on 2011-09-20 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text presents the most effective analysis for predicting the true stresses and deflections of concrete structures, accounting for creep and shrinkage of concrete and relaxation of prestressed reinforcement. Sustainability has become a major requirement in modern structures, which need to sustain satisfactory service over a longer life. It is not rare to specify a life span of 100 years for infrastructure such as bridges. This complete and wide-ranging study of stresses and deformations of reinforced and prestressed concrete structures focuses on design methods for avoiding the deflections and cracking that diminish serviceability. This fourth edition has a new emphasis on designing for serviceability. It has been comprehensively updated. It now includes 65 solved examples and more than 45 instructive problems with answers given at the end of the book. An accompanying website contains design calculation programs, which allow interactive data input. Independent of codes of practice, the book is universally applicable, and is especially suitable for practising engineers and graduate students.
Download or read book Concepts and Applications of Finite Element Analysis written by Robert D. Cook and published by John Wiley & Sons. This book was released on 2001-10-29 with total page 744 pages. Available in PDF, EPUB and Kindle. Book excerpt: Authors Cook, Malkus, Plesha and Witt have revised Concepts and Applications of Finite Element Analysis, a text suited for both introductory and more advanced courses in Finite Element Analysis. The fourth edition of this market leading text provides students with up-to-date coverage and clear explanations of finite element analysis concepts and modeling procedures.
Download or read book Independent Offices and Department of Housing and Urban Development Appropriations for 1970 written by United States. Congress. House. Committee on Appropriations. Subcommittee on Independent Offices and Department of Housing and Urban Development and published by . This book was released on 1969 with total page 1520 pages. Available in PDF, EPUB and Kindle. Book excerpt:
