Download or read book Prestress Losses in Concrete and the Estimation of Long term Deflections and Camber for Prestressed Concrete Bridges written by Hema Jayaseelan and published by . This book was released on 2007 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: Findings and conclusions. The results from the research showed that the proposed method shows strong correlation with the losses predicted using the NCHRP 496 method. The method also computed the long term deflection and camber that were comparable with the results obtained using the PCI Design Handbook multipliers. The results proved that the reduction in long term losses can be achieved by varying the material and design properties of prestressed concrete.

Download or read book Prestress Losses and the Estimation of Long term Deflections and Camber for Prestressed Concrete Bridges written by Hema Jayaseelan and published by . This book was released on 2007 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Analysis and Design of Prestressed Concrete written by Di Hu and published by Elsevier. This book was released on 2022-04-17 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt: Prestressing concrete technology is critical to understanding problems in existing civic structures including railway and highway bridges; to the rehabilitation of older structures; and to the design of new high-speed railway and long-span highway bridges. Analysis and Design of Prestressed Concrete delivers foundational concepts, and the latest research and design methods for the engineering of prestressed concrete, paying particular attention to crack resistance in the design of high-speed railway and long-span highway prestressed concrete bridges. The volume offers readers a comprehensive resource on prestressing technology and applications, as well as the advanced treatment of prestress losses and performance. Key aspects of this volume include analysis and design of prestressed concrete structures using a prestressing knowledge system, from initial stages to service; detailed loss calculation; time-dependent analysis on cross-sectional stresses; straightforward, simplified methods specified in codes; and in-depth calculation methods. Sixteen chapters combine standards and current research, theoretical analysis, and design methods into a practical resource on the analysis and design of prestressed concrete, as well as presenting novel calculation methods and theoretical models of practical use to engineers. - Presents a new approach to calculating prestress losses due to anchorage seating - Provides a unified method for calculating long-term prestress loss - Details cross-sectional stress analysis of prestressed concrete beams from jacking to service - Explains a new calculation method for long-term deflection of beams caused by creep and shrinkage - Gives a new theoretical model for calculating long-term crack width

Download or read book The Story of the Koror Bridge written by Man-Chung Tang and published by International Association for Bridge and Structural Engineering (IABSE). This book was released on 2014-01-01 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: Koror Babeldaob Bridge, also called Koror Babelthuap Bridge or simply Koror Bridge, connects the islands of Koror and Babeldaob in the Republic of Palau. The design of the bridge began in 1974 and was based on the prevailing AASHO Standard Specifications at that time and was supplemented by ACI and CEB-FIP design recommendations on an as-needed basis. When the Koror Bridge was opened to traffic in April 1977, it was the world's longest concrete girder span. A few years later, the bridge began to deflect more than had been anticipated. The owner commissioned a Japanese engineering firm in 1985 and then a US engineering firm in 1993 to conduct in-depth investigations of the structure. Both firms came to the same conclusion that the bridge was structurally safe and that the excessive deflection was an unexplainable phenomenon. Nevertheless, in order to improve the driving quality of the bridge deck, the owner decided to repair the bridge. The repair scheme made changes to the structural system and added a large amount of post-tensioning force to the bridge. Unfortunately, less than three months after the repair, late in the afternoon on 26 September 1996, nineteen and a half years after it was opened to traffic, the bridge collapsed. Thereafter, most of the documents were sealed as a result of litigation between the various parties, and the debris was cleared. For a long time, it was impossible to study the facts surrounding the bridge's collapse. Only recently, through continuous probing by a group of engineers, were these documents made accessible to researchers.

Download or read book Validation of Prestressed Concrete I beam Deflection and Camber Estimates written by Cullen R. OʹNeill and published by . This book was released on 2012 with total page 205 pages. Available in PDF, EPUB and Kindle. Book excerpt: The camber at the time of bridge erection of prestressed concrete bridge girders predicted by the Minnesota Department of Transportation (MnDOT) was observed to often overestimate the measured cambers of girders erected at bridge sites in Minnesota, which, in some cases, was causing significant problems related to the formation of the bridge deck profile, the composite behavior of the girders and bridge deck, delays in construction and increased costs. Extensive historical data was collected from two precasting plants and MN counties and it was found that, on average, the measured cambers at release and erection were only 74% and 83.5%, respectively, of the design values. Through data collection, analysis, and material testing, it was found that the primary causes of the low camber at release were concrete release strengths that exceeded the design values, the use of an equation for concrete elastic modulus that greatly under-predicted the measured values, and thermal prestress losses not accounted for in design. Fourteen girders were instrumented and their camber measured and the program PBEAM was used to evaluate the influence of various time-dependent effects (i.e., solar radiation, relative humidity, concrete creep and shrinkage, length of cure and bunking/storage conditions) on long-term camber. Once investigated, these effects were included in long-term camber predictions that were used to create sets of both time-dependent and singlevalue camber multipliers. The use of these multipliers, along with modifications made to the elastic release camber calculations, greatly reduced the observed discrepancy between measured and design release and erection cambers.

Download or read book Predicting Camber Deflection and Prestress Losses in Prestressed Concrete Members written by S. H. Rizkalla and published by . This book was released on 2011 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt: Accurate predictions of camber and prestress losses for prestressed concrete bridge girders are essential to minimizing the frequency and cost of construction problems. The time-dependent nature of prestress losses, variable concrete properties, and problems related to production variables make it difficult to predict camber accurately. The recent problems experienced by NCDOT during construction are mainly related to inaccurate prediction of camber. In this report, several factors related to girder production are shown to have a significant impact on the prediction of camber. A detailed method and an approximate method for predicting camber that both utilize adjustments to account for the production factors are proposed. The detailed method uses time-dependent losses calculations and creep factors to predict camber, while the approximate method uses multipliers. The current NCDOT method and the proposed methods are analyzed and compared using an extensive database of field measurements. The proposed methods are shown to provide significant improvements to the camber predictions in comparison to the current NCDOT method. Recommendations for design and production practices are provided.

Download or read book Field Measurement and Evaluation of Time dependent Losses in Prestressed Concrete Bridges written by Okey U. Onyemelukwe and published by . This book was released on 1997 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Structural Concrete written by M. Nadim Hassoun and published by John Wiley & Sons. This book was released on 2020-02-26 with total page 962 pages. Available in PDF, EPUB and Kindle. Book excerpt: The leading structural concrete design reference for over two decades—updated to reflect the latest ACI 318-19 code A go-to resource for structural engineering students and professionals for over twenty years, this newly updated text on concrete structural design and analysis reflects the most recent ACI 318-19 code. It emphasizes student comprehension by presenting design methods alongside relevant codes and standards. It also offers numerous examples (presented using SI units and US-SI conversion factors) and practice problems to guide students through the analysis and design of each type of structural member. New to Structural Concrete: Theory and Design, Seventh Edition are code provisions for transverse reinforcement and shear in wide beams, hanger reinforcement, and bi-directional interaction of one-way shear. This edition also includes the latest information on two-way shear strength, ordinary walls, seismic loads, reinforcement detailing and analysis, and materials requirements. This book covers the historical background of structural concrete; advantages and disadvantages; codes and practice; and design philosophy and concepts. It then launches into a discussion of the properties of reinforced concrete, and continues with chapters on flexural analysis and design; deflection and control of cracking; development length of reinforcing bars; designing with the strut-and-tie method; one-way slabs; axially loaded columns; and more. Updated to align with the new ACI 318-19 code with new code provisions to include: transverse reinforcement and shear in wide beams, hanger reinforcement, bi-directional interaction of one-way shear, and reference to ACI certifications Includes dozens of worked examples that explain the analysis and design of structural members Offers updated information on two-way shear strength, seismic loads, materials requirements, and more Improves the design ability of students by explaining code requirements and restrictions Provides examples in SI units in every chapter as well as conversion factors from customary units to SI Offers instructors access to a solutions manual via the book's companion website Structural Concrete: Theory and Design, Seventh Edition is an excellent text for undergraduate and graduate students in civil and structural engineering programs. It will also benefit concrete designers, structural engineers, and civil engineers focused on structures.

Download or read book PCI Journal written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Prestress Loss and Creep Camber in a Highway Bridge with Reinforced Concrete Slab on Pretensioned Prestressed Concrete Beams written by Howard L. Furr and published by . This book was released on 1968 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Loss of Prestress and Camber of Non composite and Composite Prestressed Concrete Structures written by Dan E. Branson and published by . This book was released on 1970 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Loss of Prestress Camber and Deflection of Non composite and Composite Structures Using Different Weight Concretes Final Report written by D. E. Branson and published by . This book was released on 1970 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Predicting Prestress Losses Camber and Deflection in Prestressed Concrete Members written by Tyler Keith Storm and published by . This book was released on 2011 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advanced Composites in Bridge Construction and Repair written by Yail Jimmy Kim and published by Elsevier. This book was released on 2014-05-16 with total page 367 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced composite materials for bridge structures are recognized as a promising alternative to conventional construction materials such as steel. After an introductory overview and an assessment of the characteristics of bonds between composites and quasi-brittle structures, Advanced Composites in Bridge Construction and Repair reviews the use of advanced composites in the design and construction of bridges, including damage identification and the use of large rupture strain fiber-reinforced polymer (FRP) composites. The second part of the book presents key applications of FRP composites in bridge construction and repair, including the use of all-composite superstructures for accelerated bridge construction, engineered cementitious composites for bridge decks, carbon fiber-reinforced polymer composites for cable-stayed bridges and for repair of deteriorated bridge substructures, and finally the use of FRP composites in the sustainable replacement of ageing bridge superstructures. Advanced Composites in Bridge Construction and Repair is a technical guide for engineering professionals requiring an understanding of the use of composite materials in bridge construction. - Reviews key applications of fiber-reinforced polymer (FRP) composites in bridge construction and repair - Summarizes key recent research in the suitability of advanced composite materials for bridge structures as an alternative to conventional construction materials

Download or read book Symposium Proceedings written by L. S. Johal and published by . This book was released on 1997 with total page 750 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Prestressed Concrete Structures Creep Shrinkage Deflection Studies 1961 written by National Research Council (U.S.). Highway Research Board and published by . This book was released on 1962 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Recommendations for Estimating Prestress Losses written by Prestressed Concrete Institute. Committee on Prestress Losses and published by . This book was released on 1975* with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: