Download or read book Volume change Restraining Effects in Continuous Precast prestressed Bridge Girders written by Athul Abraham Alex and published by . This book was released on 2016 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt: A variety of design and construction practices are feasible when building precast concrete continuous bridges with long spans. Precast, prestressed concrete continuous bridges have been implemented by countries around the world. Although these bridges have been in service for many years, there has been limited verification of the ability of connection to provide the predicted continuity. Subsequently many states in the United States design the girders as simple spans for both dead and live loads without considering any moments developed by the connection. The effect of thermal expansion and contraction is hardly considered in the analysis, even though it is found to have significant effects on continuity. The objective of this study is to evaluate the current state of the art practices relevant to continuous precast concrete bridges and to recommend the most suitable design methods of analyzing the continuity behavior. This research focuses on providing detailed analysis to evaluate the restraining effects in a continuous bridge system. Detailed analysis was performed using the specifications of the NU-girder system, which has been a widely adopted solution in the State of Nebraska. This research consisted of two phases: Phase 1: Conduct an extensive literature survey to find information regarding existing continuity behavior as investigated by various researchers. Phase 2: Propose the most suitable method for analyzing connection design. Discuss advantages, construction time and cost comparisons of the NU-girder system with other systems adopted in the United States.
Download or read book Design of Precast Prestressed Bridge Girders Made Continuous written by R. G. Oesterle and published by Transportation Research Board National Research. This book was released on 1989 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report documents and presents results of a study to determine time-dependent behavior and relevant design criteria for simple-span precast, prestressed bridge girders made continuous. A questionnaire was used to determine current practice. Creep and shrinkage tests of steam-cured concrete loaded at an early age were made. Computer simulations were used to investigate the effects of time-dependent material behavior and variation in design parameters on the effective continuity for live load plus impact. The findings suggest that positive moment connections in the diaphragms at the piers are not required and provide no structural advantages. The findings also suggest that effective continuity for live load plus impact can vary from 0 to 100% dependent on the design parameters and timing of construction. Computer analyses were also used to determine an upper limit for the amount of negative moment reinforcement over the supports to insure full moment redistribution and attainment of maximum bridge strength. New computer programs were developed for simplified analysis to determine time-dependent effects and service moments. Recommendations for design procedures were presented and design examples given.
Download or read book Highway Research and Development Studies Using Federal aid Research and Planning Funds written by and published by . This book was released on 1968 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Design of Continuous Prestressed Concrete Bridge Girders written by Ali Pahlavan and published by . This book was released on 1958 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Expansion Joints in Buildings written by National Research Council and published by National Academies Press. This book was released on 1974-02-01 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many factors affect the amount of temperature-induced movement that occurs in a building and the extent to which this movement can occur before serious damage develops or extensive maintenance is required. In some cases joints are being omitted where they are needed, creating a risk of structural failures or causing unnecessary operations and maintenance costs. In other cases, expansion joints are being used where they are not required, increasing the initial cost of construction and creating space utilization problems. As of 1974, there were no nationally acceptable procedures for precise determination of the size and the location of expansion joints in buildings. Most designers and federal construction agencies individually adopted and developed guidelines based on experience and rough calculations leading to significant differences in the various guidelines used for locating and sizing expansion joints. In response to this complex problem, Expansion Joints in Buildings: Technical Report No. 65 provides federal agencies with practical procedures for evaluating the need for through-building expansion joints in structural framing systems. The report offers guidelines and criteria to standardize the practice of expansion joints in buildings and decrease problems associated with the misuse of expansions joints. Expansions Joints in Buildings: Technical Report No. 65 also makes notable recommendations concerning expansion, isolation, joints, and the manner in which they permit separate segments of the structural frame to expand and to contract in response to temperature fluctuations without adversely affecting the buildings structural integrity or serviceability.
Download or read book Highway Research Development Studies written by United States. Bureau of Public Roads. Office of Research and Development and published by . This book was released on 1968 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book PCI Journal written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Prestress Losses in Pretensioned High strength Concrete Bridge Girders written by Maher K. Tadros and published by Transportation Research Board. This book was released on 2003 with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The HCM includes three printed volumes (Volumes 1-3) that can be purchased from the Transportation Research Board in print and electronic formats. Volume 4 is a free online resource that supports the rest of the manual. It includes: Supplemental chapters 25-38, providing additional details of the methodologies described in the Volume 1-3 chapters, example problems, and other resources; A technical reference library providing access to a significant portion of the research supporting HCM methods; Two applications guides demonstrating how the HCM can be applied to planning-level analysis and a variety of traffic operations applications; Interpretations, updates, and errata for the HCM (as they are developed);A discussion forum allowing HCM users to ask questions and collaborate on HCM-related matters; and Notifications of chapter updates, active discussions, and more via an optional e-mail notification feature."--Publisher.
Download or read book Investigation of the Effects of End Region Deterioration in Precast Prestressed Concrete Bridge Girders written by Darion Timothy Mayhorn and published by . This book was released on 2016 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings written by and published by . This book was released on 1990 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Connection Between Simple Span Precast Concrete Girders Made Continuous written by Amy J. Dimmerling and published by . This book was released on 2002 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: Precast prestressed concrete girders have been used in bridge construction for several years in the United States. In general, these types of bridges have performed well in service conditions. Although the connections over the supports provide sufficient continuity for dead loads, which cause negative moments, there has been some concern about the ability of the connections to provide continuity for the positive moments caused by live loads. Cracking has been observed at the bottom of the diaphragm at the connection and this raises concern about the connection's performance. The National Cooperative Highway Research Program developed Project 12-53 to study the effectiveness of these connections. The focus of this research deals with the experimental testing part of project 12-53. Six specimens that represent portions of full-size bridges were tested under monotonic and cyclic loads to evaluate their performance after cracking occurs at the bottom of the diaphragm. Each connection was fatigued until the connection was considered to have failed. The bent strand and bent bar embedded connections performed well under service moments. Under negative moment all of the specimens performed well. Even after failure of the specimens they each were able to resist the negative moment. This was due to the bearing of the diaphragm against the beams. The crack closes and at this point there is no difference between the specimens. Under positive moment the embedded specimens were stiffer and the failure was more gradual than that of the not embedded specimens. The embedment adds to the stiffness of the specimens. The engagement of the diaphragm in the embedded specimens helps to prolong the failure. The warning signs of failure are more prominent in the embedded specimens. The bent bar specimens are stiffer than the bent strand but the failure occurs more rapidly. After all six of the short-length specimens are tested, full-size specimens will be tested. At that point, results from all testing will be compared and discussed providing conclusions about the behavior of positive moment connections. Also, recommendations are expected as to the design and construction of positive moment connections in precast/prestressed bridge girders made continuous.
Download or read book Design of Precast Prestressed Bridge Girders Made Continuous written by and published by . This book was released on 1989 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1969 with total page 736 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Stability of Precast Prestressed Concrete Bridge Girders Considering Sweep and Thermal Effects written by Lawrence F. Kahn and published by . This book was released on 2009 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Journal of the American Concrete Institute written by American Concrete Institute and published by . This book was released on 1986 with total page 1126 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Design of Precast Prestressed Bridge Girders Made Continuous written by R. G. Oesterle and published by . This book was released on 1964 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Stability of Precast Prestressed Concrete Bridge Girders Considering Imperfections and Thermal Effects written by Jonathan B. Hurff and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The spans of precast prestressed concrete bridge girders have become longer to provide more economical and safer transportation structures. As the spans have increased, so has the depth of the girders which in turn have increased the slenderness of the girders. Slenderness in a beam or girder would increase the likelihood that a stability failure would occur. Stability failures could pose a danger to construction personnel due to the sudden nature in which a stability failure would occur. Furthermore, stability failures of prestressed concrete girders during construction would cause a detrimental economic impact due to the costs associated with the failure of the girder, the ensuing construction delays, damage to construction equipment and potential closures to highways over which the bridge was being constructed.
