Shear Behavior of Full-Scale Prestressed Concrete Girders: Comparison Between AASHTO Specifications and LRFD Code

摘要

style="text-align: left;">An extensive laboratory testing program was conducted to investigate the shear strength of prestressed concrete girders. A comparison between the various models for predicting shear strength and the  results of tests on twenty full-scale AASHTO Type II prestressed concrete girders are presented. Three of the test girders contained no shear reinforcement and were tested to determine the concrete  contribution, V, to shear strength. The main variables of this study were the amounts of shear reinforcement and the shear span. The test shear strengths are compared with predictions based on the 1989  AASHTO Standard Specifications for Highway Bridges and the 1994 AASHTO LRFD Specifications. The results show that the application of the 1989 AASHTO Specifications gives a much better  prediction of shear strength than the LRFD provisions, indicating that the latter require some examination and modification to increase reliability >References>1. ACI Committee 318, a€?Building Code Requirements for Reinforced Concrete,a€? American Concrete Institute, Farmington Hills, MI, 1989 and 1995. >2. AASHTO, Standard Specifications for Highway Bridges, American Association of State Highway and Transportation Officials, Washington, D.C., 1977. >3. Ontario Highway Bridge Design Code, Engineering Division, Ministry of Transportation and Communications, Toronto, Ontario, Canada, 1993. >4. Collins, M. P., and Mitchell, D., href="http://dx.doi.org/10.15554/pcij.09011980.32.100 " title="a€?Shear and Torsion Design of Prestressed and Non-Prestressed Concrete Beams,a€? " target="_blank">a€?Shear and Torsion Design of Prestressed and Non-Prestressed Concrete Beams,a€? PCI JOURNAL, V. 25, No. 5, September- October 1980, pp. 32-100. >5. Collins, M. P., and Mitchell, D., Prestressed Concrete Structures, Prentice Hall, Englewood Cliffs, NJ, 1991, a€?76tlpp. 6. AASHTO, LRFD Code for the Design of Highway Bridges, American Association of State Highway and Transportation Officials Washington, D.C., 1994. >7. Shahawy, M., Robinson, B., and Batchelor, B. deV., a€?An Investigation ofShear Strength of Prestressed Concrete AASHTO Type II Girders,a€? Research Report, Structures Research Center, Florida     Department of Transportation, Tallahassee, FL, January 1993. >8. Shahawy, M., Issa, M., and Batchelor, B. deV., href="http://dx.doi.org/10.15554/pcij.05011992.84.96 " title="a€?Strand Transfer Lengths of Full Scale AASHTO Prestressed Concrete Girders,a€?" target="_blank">a€?Strand Transfer Lengths of Full Scale AASHTO Prestressed Concrete Girders,a€? PCI JOURNAL, V. 37, No. 3, May-June 1992, pp. 84-96.