PRESTRESSED BOX BEAMS UNDER COMBINED LOADING

Prestressed concrete box beams are studied under combined loadings of torsion, bending, and shear. Thirty-seven eccentrically prestressed beams were tested--three under pure torsion, 10 under varying ratios of torsion and bending, and 24 under varying ratios of torsion, bending and shear. All beams had a 12-in. (305-mm) square cross section with an 8-1/2-in. (220-mm) diam hollow for the full length. Most of the beams contained web reinforcement in either of two stirrup spacings, but five beams without web reinforcement were also tested. Two shear span-to-depth ratios were utilized. Tests results include cracking patterns and strengths, ultimate failure modes and strengths, torque-twist, and flexural deformations. Analytical theories are developed for the initial cracking torque based upon elastic theory and for the ultimate strength based upon the skewed bending failure mechanism for prestressed concrete beams. Comparisons of the theoretical and experimental results are presented, and these generally correlated well.

• Corporate Authors:

  American Society of Civil Engineers

  345 East 47th Street
  New York, NY  United States  10017-2398
• Authors:
  • Johnston, D W
  • Zia, P
• Publication Date: 1975-7

Media Info

• Features: Appendices; Figures; References; Tables;
• Pagination: p. 1313-31
• Serial:
  • Journal of the Structural Division
  • Volume: 101
  • Issue Number: ST7
  • Publisher: American Society of Civil Engineers

Subject/Index Terms

• TRT Terms: Beams; Bending; Box beams; Eccentricity; Fracture mechanics; Loads; Prestressed concrete; Prestressing; Shear strength; Torsion; Ultimate strength; Webbing
• Uncontrolled Terms: Eccentric loading; Loading
• Subject Areas: Bridges and other structures; Highways;

Filing Info

• Accession Number: 00126468
• Record Type: Publication
• Report/Paper Numbers: ASCE #11421 Proceeding
• Files: TRIS
• Created Date: Dec 16 1975 12:00AM