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Showing 1 to 18 of 18 for “"prestress loss"”.
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Transfer Length, Development Length, Flexural Strength, and Prestress Loss Evaluation in Pretensioned Self-Consolidating Concrete Members
… development lengths, and flexural strengths of prestressed members. Three small rectangular members were made, two cast with SCC mixes and one cast with a conventional mix, to determine the transfer length of each mix. Transfer lengths of both ends of each member were determined by measuring the …
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Investigation of Transfer Length, Development Length, Flexural Strength and Prestress Loss Trend in Fully Bonded High Strength Lightweight Prestressed Girders
… conducted on two AASHTO Type IV HSLWC prestressed girders, resulted in an average transfer length of 17 inches, well below the AASHTO and ACI guidance. Two girders composed of HSLWC AASHTO Type II girders and a 48" x 8" normal weight 4000-psi concrete deck were produced. The HSLWC Type …
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Investigation of the Time-Dependent Longitudinal Flexural Behavior of the Varina-Enon Bridge
… bridge construction. Over time, the force in the prestressing strands is reduced by delayed strains in the concrete. The accurate estimation of this prestress loss is vital for making good decisions about the remaining capacity of a structure and the infrastructure system at large. The Varina-Enon …
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Structural Performance of High Strength Lightweight Concrete Pretensioned Bridge Girders
The use of high compressive strengths in prestressed bridge girders can lower costs by allowing for longer spans, increased girder spacing, and smaller cross-sections. If high strength lightweight concrete (HSLWC) is used, these advantages are further enhanced due to the corresponding reduction in …
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Optimization and behavior of high-performance concrete in structural applications
… as a two-part series, examine the behavior of prestressed concrete girders produced with self-consolidating concrete and subjected to elevated compressive fiber stress levels. Members were monitored to examine the prestress loss behavior and the camber development over time, then tested to …
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Long-Term Monitoring and Evaluation of the Varina-Enon Bridge
… of a structure, the precise calculation of the prestress losses is very important. In post-tensioned structures, the prestress losses due to creep and shrinkage can cause serviceability issues and can reduce flexural capacity. The Varina-Enon Bridge is a cable-stayed, precast, segmental, …
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Structural Condition Assessment Of Prestressed Concrete Transit Guideways
… system is composed of six-span continuous prestressed concrete bridge segments. The overall transit system incorporates a number of continuous bridges which share common design details, geometries, and loading conditions. The original analysis is based on certain simplifying assumptions …
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Investigation of Time-Dependent Deflection in Long Span, High Strength, Prestressed Concrete Bridge Beams
Accurate camber prediction in prestressed concrete bridge beams is important to all parties involved in bridge design and construction. Many current prestress loss prediction methods, necessary for proper camber calculation, were developed many years ago and are predicated on assumptions that may …
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Structural Performance of Longitudinally Post-Tensioned Precast Deck Panel Bridges
… parametric study results of Bowers' research on prestress loss within full-depth precast deck panel bridges. It was determined that the bridge was acting compositely and that the post-tensioning force was sufficient in keeping the joints in compression during testing.
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Prestressed PCBT Girders Made Continuous and Composite with a Cast-in-place Deck and Diaphragm
This research document focuses on prestressed PCBT girders made composite with a cast-in-place concrete deck and continuous over several spans through the use of continuity diaphragms. The current design procedure in AASHTO states that a continuity diaphragm is considered to be fully effective if a …
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Evaluation of the residual prestress force in aged railway concrete sleepers considered for reuse
… of a conventional railway track is the prestressed concrete sleeper. In South Africa, these sleepers are designed to last for 40 years, and their replacement plan is aligned with their design life. Given the desire to extend the useful life of sleepers, aged concrete sleepers are often …
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Top Strand Effect and Evaluation of Effective Prestress in Prestressed Concrete Beams
… orientation on bond strength in pretensioned prestressed concrete members. The "top strand effect" was evaluated through transfer and development length tests of prestressed concrete beams. Eight beams were cast with normal orientation, while four beams were cast with inverted orientation so …
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Structural assessment of bridges using monitoring data
… assessment are examined. These are the amount of prestress loss (for prestressed concrete bridges), load distribution characteristics, support boundary conditions and the stiffness contribution of secondary structural elements. Novel or refined methods are developed to enable the evaluation of …
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Shear Strength of a PCBT-53 Girder Fabricated with Lightweight, Self-Consolidating Concrete
… The second goal was to monitor the change in prestress over time (and hence the prestress loss) occurring in the PCBT-53 girder. Prestress losses were experimentally measured by vibrating wire gages (measured changes in concrete strain) and flexural load testing. Measured prestress losses were …
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Prediction of Time-Dependent Stresses and Deflections in Prestressed, Concrete Girders: From Start of Fabrication to End of Service Life
… accurate prediction of the camber in precast, prestressed, concrete girders. Large differences in the camber between adjacent girders lead to significant construction difficulties that often have financial and/or legal ramifications. Many factors affect the time-dependent deflections of these …
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Refined Evaluation of Effective Prestress in the Varina-Enon Bridge
… of the bridge. Particular focus has been put on prestress losses which have a significant impact on the strength and serviceability of the bridge. Previous work has been conducted to monitor the behavior of the bridge and to back-calculate effective prestress. This was done using field data from …
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Effective Prestress Evaluation of the Varina-Enon Bridge Using a Long-Term Monitoring System and Finite Element Model
… 2012 that prompted concerns regarding long-term prestress losses in the structure. Prestress losses could impact the future performance, serviceability, and flexural strength of the bridge. Accurately quantifying prestress losses is critical for understanding and maintaining the structure during …