Time-Dependent Deformation Behavior of Prestressed High Performance Concrete211 Bridge Beams

摘要

The primary objective of this research program was to develop guidelines for the211u001edesign and construction of highway bridge structures that utilize high 211u001eperformance concrete. These guidelines were developed by monitoring the entire 211u001econstruction process for an actual bridge project. Furthermore, this study 211u001edocumented several benefits that could be realized through the use of high 211u001eperformance concrete. The site that has been chosen for the implementation of 211u001ethis resarch was the Louetta Road Overpass on State of Texas Highway 249 in 211u001eHouston Texas. The objective of this portion of the research program was to 211u001emonitor the long-term deformation behavior of pretesioned high performance 211u001econcrete bridge girders. This study focused on the field instrumentation of 211u001etwelve high performance concrete Texas Type U54 beams pretensioned with 15.2 mm-211u001ediameter low-relaxation strands. Beam cambers and deflections, concrete strains, 211u001eand concrete temperatures were monitored from transfer of prestressing force 211u001ethrough placement of the precast concrete deck panels and cast-in-place concrete 211u001edeck on the girders in the bridge. The measured cambers and prestress losses were 211u001ecompared to predicted values obtained using current design and analysis 211u001eprocedures. This study presents preliminary design considerations for estimating 211u001ethe long-term behavior of pretensioned high performance concrete girders.