Shear Capacity of in Service Prestressed Concrete Bridge Girders - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Shear Capacity of in Service Prestressed Concrete Bridge Girders write by Paul Barr. This book was released on 2010. Shear Capacity of in Service Prestressed Concrete Bridge Girders available in PDF, EPUB and Kindle. The design procedure to calculate the shear capacity of bridge girders that was used forty years ago is very different than those procedures that are recommended in the current AASHTO LRFD Specifications. As a result, many bridge girders that were built forty years ago do not meet current design standards, and in some cases warrant replacement due to insufficient calculated shear capacity. However despite this insufficient calculated capacity, these bridge girders have been found to function adequately in service with minimal signs of distress. The objective of this research was to investigate the actual in service capacity of prestressed concrete girders that have been in service over an extended period of time.
Shear Capacity of in Service Prestressed Concrete Bridge Girders
Shear Capacity of in Service Prestressed Concrete Bridge Girders - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Shear Capacity of in Service Prestressed Concrete Bridge Girders write by . This book was released on 1988. Shear Capacity of in Service Prestressed Concrete Bridge Girders available in PDF, EPUB and Kindle. The design of prestressed concrete bridge girders has changed significantly over the past several decades. Specifically, the design procedure to calculate the shear capacity of bridge girders that was used forty years ago is very different than those procedures that are recommended in the current AASHTO LRFD Specifications. As a result, many bridge girders that were built forty years ago do not meet current design standards, and in some cases warrant replacement due to insufficient calculated shear capacity. However, despite this insufficient calculated capacity, these bridge girders have been found to function adequately in service with minimal signs of distress. The objective of this research was to investigate the actual in service capacity of prestressed concrete girders that have been in service over an extended period of time. The actual capacity was compared with calculated values using the AASHTO LRFD Specifications.
Ultimate Shear Capacity and Residual Prestress Force of Full-scale, Forty-one-year-old Prestressed-concrete Girders
Ultimate Shear Capacity and Residual Prestress Force of Full-scale, Forty-one-year-old Prestressed-concrete Girders - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Ultimate Shear Capacity and Residual Prestress Force of Full-scale, Forty-one-year-old Prestressed-concrete Girders write by Parry Osborn. This book was released on 2010. Ultimate Shear Capacity and Residual Prestress Force of Full-scale, Forty-one-year-old Prestressed-concrete Girders available in PDF, EPUB and Kindle. The ultimate shear capacity of prestressed concrete beams is difficult to predict accurately, especially after being in service for an extended period of time. The Utah Department of Transportation asked researchers at Utah State University to experimentally determine the existing shear capacity of 41-year-old prestressed, decommissioned concrete bridge girders and then provide recommendations on how to increase that ultimate shear capacity. This thesis presents the research findings that relate to the existing shear capacity of the prestressed concrete girders. Eight AASHTO Type II bridge girders were tested up to failure by applying external loads near the supports to determine their ultimate shear capacities. The measured results were then compared to calculated values obtained using the AASHTO LRFD bridge design code, and the ACI 318-08 design code. Prestress losses were also measured by means of a cracking test and then compared to values calculated according to the AASHTO prestress loss equations. Both the ultimate shear capacities and the residual prestress forces were used to evaluate the girders after being in service for more than 40 years.
Discrepancies in Shear Strength of Prestressed Beams with Different Specifications
Discrepancies in Shear Strength of Prestressed Beams with Different Specifications - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Discrepancies in Shear Strength of Prestressed Beams with Different Specifications write by Ozer Dereli. This book was released on 2010. Discrepancies in Shear Strength of Prestressed Beams with Different Specifications available in PDF, EPUB and Kindle. Although Mn/DOT inspection reports indicate that prestressed concrete bridge girders in service do not show signs of shear distress, girders rated with the Virtis-BRASS rating tool and Load Factor Rating (LFR) have indicated that a number of the girders have capacities lower than design level capacities. One of the reasons for the discrepancy was suspected to be conservatism of the rating methods (i.e., LFR). Other suspected reasons included potential flaws in the rating tools used by Mn/DOT (i.e., Virtis-BRASS software) including neglecting possible additional shear capacity parameters (e.g., end blocks). As a consequence, the rating methods have made it difficult to discern the cases for which shear capacity may be a real concern. In order to identify the reasons for the discrepancies and inconsistency in rating results relative to observed performance of the prestressed bridge girders, an analytical research program was conducted. The report provides a brief description of the models that provide the basis for the AASHTO shear design provisions and descriptions of the provisions through the 2002 AASHTO Standard specifications. This is followed by a description of the Virtis-BRASS rating tool, which was verified with example bridges provided by Mn/DOT. To investigate prestressed bridge girders within the inventory that might be most at risk for being undercapacity for shear, 54 girders were selected from the inventory for further evaluation. Some of the 54 girders were found to have larger stirrup spacings than required at the time of design. These girders were subsequently rated and evaluated per the 2002 AASHTO Standard Specifications to determine the adequacy of the designs based on the LFR inventory and operating rating methods. Potential sources for increased shear capacity were identified and reviewed.
Shear Reinforcement Requirements for High-Strength Concrete Bridge Girders
Shear Reinforcement Requirements for High-Strength Concrete Bridge Girders - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Shear Reinforcement Requirements for High-Strength Concrete Bridge Girders write by J.A. Ramirez. This book was released on 2005-07-15. Shear Reinforcement Requirements for High-Strength Concrete Bridge Girders available in PDF, EPUB and Kindle.
