A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Development of an Optimized Continuity Diaphragm for New PCBT Girders
Over the past 50 years, many states have recognized the benefits of making precast, prestressed multi-girder bridges continuous by connecting the girders with a continuity diaphragm. Although there is widespread agreement on the benefits of continuous construction, there has not been as much agreement on either the methods used for design of these systems or the details used for the continuity connections. To aid designers in choosing the most appropriate method, an analytical and experimental study was undertaken at Virginia Tech. Analyses were done to compare the differences in the predicted continuity moments for different design methods and assumptions over a range of commonly used systems of precast concrete bulb tee (PCBT) girders and cast-in-place slabs. The results of the analyses were used to develop three continuity connection details for testing during the experimental study. Three different continuity connections were tested using full-depth PCBT 45 in deep girders made continuous with a 6 ft wide slab. The bottom of the ends of the girders were made continuous with the continuity connection by extending prestressing strands for the first test and extending 180 degree bent bars for the second test. Both connections adequately resisted service, cyclic, and ultimate loads. But, the test with the extended bars remained stiffer during cyclic loading and is recommended for use. The third test was performed on a system using only a slab cast across the top of the girders without the full-depth diaphragm. Two primary cracks formed above the ends of the girders at the joint during service testing, after which no significant increase in damage took place.
Development of an Optimized Continuity Diaphragm for New PCBT Girders
Over the past 50 years, many states have recognized the benefits of making precast, prestressed multi-girder bridges continuous by connecting the girders with a continuity diaphragm. Although there is widespread agreement on the benefits of continuous construction, there has not been as much agreement on either the methods used for design of these systems or the details used for the continuity connections. To aid designers in choosing the most appropriate method, an analytical and experimental study was undertaken at Virginia Tech. Analyses were done to compare the differences in the predicted continuity moments for different design methods and assumptions over a range of commonly used systems of precast concrete bulb tee (PCBT) girders and cast-in-place slabs. The results of the analyses were used to develop three continuity connection details for testing during the experimental study. Three different continuity connections were tested using full-depth PCBT 45 in deep girders made continuous with a 6 ft wide slab. The bottom of the ends of the girders were made continuous with the continuity connection by extending prestressing strands for the first test and extending 180 degree bent bars for the second test. Both connections adequately resisted service, cyclic, and ultimate loads. But, the test with the extended bars remained stiffer during cyclic loading and is recommended for use. The third test was performed on a system using only a slab cast across the top of the girders without the full-depth diaphragm. Two primary cracks formed above the ends of the girders at the joint during service testing, after which no significant increase in damage took place.
Development of an Optimized Continuity Diaphragm for New PCBT Girders
C. D. Newhouse (author) / C. L. Roberts-Wollmann (author) / T. E. Cousins (author)
2005
82 pages
Report
No indication
English
Construction Equipment, Materials, & Supplies , Highway Engineering , Ceramics, Refractories, & Glass , Construction Materials, Components, & Equipment , Precast concrete , Prestressed concrete , Bridges(Structure) , Girder bridges , Diaphragms , Bents , Construction , Parameters , Deflections , Bridge girders , Concrete bridges , Continuous bridges , Continuity diaphragms , Stresses , Bulb-tee girders
The Effect of Temperature on the Effective Prestressing Force at Release for PCBT Girders
| British Library Conference Proceedings | 2008
Properties of POSS blends with pCBT, PMMA, PC and POM thermoplastics
| British Library Online Contents | 2013
Continuous plate girders without continuity? - Investigations on steel girders with slender webs
| Online Contents | 1997
Continuous plate girders without continuity? - Investigations on steel girders with slender webs
| Online Contents | 1997