Experimental Behavior of Reinforced Concrete and Pretensioned Concrete Bent Caps
Publication: Journal of Bridge Engineering
Volume 25, Issue 2
Abstract
Accelerated bridge construction using precast bridge substructures can enable reduction of traffic disruption, increased worker safety, and increased quality through controlled conditions at the time of fabrication. A largely unrealized benefit of precast substructures is the use of pretensioned bent caps that can provide superior performance to that of reinforced concrete bent caps. Full-scale experimental tests of reinforced concrete (RC) and pretensioned, prestressed concrete (PSC) bent cap subassemblies were conducted to verify the improved performance of pretensioned caps. Flexural reinforcing bars and strands were distributed along the sides of the bent cap to accommodate a pocket connection designed to provide large construction tolerances. Results showed superior performance of the pretensioned cap, including delayed initial cracking, smaller average flexure crack widths, and absence of shear cracking. Removal of live loads resulted in full closure of cracks, validating the design philosophy of zero tension under dead load.
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Acknowledgments
This research was supported by the Texas Department of Transportation (TxDOT) under Project No. 0-6863. The authors wish to thank TxDOT personnel for assistance, including Darrin Jensen, Jason Tucker, Todd Speck, Courtney Holle, Christopher Miller, Graham Bettis, Manuel Pardon Jr., Susana Ceballos, Frank Estrada III, Dennis Johnson, and Roger Lopez. The pretensioned bent cap was fabricated at Bexar Concrete Works in San Antonio, Texas; the assistance of Jorge Hinojosa and his staff are greatly appreciated. The authors would also like to thank the staff of the TAMU high-bay lab and the many graduate and undergraduate students who assisted in the construction and testing of the bent caps.
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Information & Authors
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Published In
Journal of Bridge Engineering
Volume 25 • Issue 2 • February 2020
Copyright
©2019 American Society of Civil Engineers.
History
Received: Feb 16, 2018
Accepted: Nov 8, 2018
Published online: Nov 20, 2019
Published in print: Feb 1, 2020
Discussion open until: Apr 20, 2020
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