ARCH ACTION AND BOND IN CONCRETE SHEAR FAILURES

NUMEROUS INVESTIGATORS HAVE SUGGESTED THAT A CRACKED REINFORCED BEAM WITHOUT WEB STEEL BEHAVES LIKE A TIED-ARCH. FROM A STUDY OF STRAIN MEASUREMENTS IN STEEL AND ON CONCRETE, IT IS SHOWN THAT A NORMALLY REINFORCED BEAM FAILING IN SHEAR BEHAVES ESSENTIALLY LIKE A BEAM UP TO FAILURE, IN SPITE OF EXTENSIVE CRACKING AND DEFORMATION. EXTERNAL LOADS CAN BE RESISTED BY ARCH ACTION ONLY WHEN THE WEB ACTS IN COMPRESSION. DATA REPORTED SHOW THAT SUCH ACTION CAN DEVELOP IN A BEAM ONLY WHEN THE STEEL IS FULLY UNBONDED BETWEEN STRONG END ANCHORAGES. ARCH ACTION ENHANCES THE SHEAR RESISTANCE OF AN UNBONDED BEAM BEYOND THAT OF A BONDED BEAM FAILING IN SHEAR BUT ALSO INCREASES DEFLECTION AND REDUCES THE FLEXURAL CAPACITY. LACK OF BOND, HOWEVER, IS NOT A GUARANTEE AGAINST SHEAR FAILURE OR EVEN DIAGONAL CRACKING. THE SURFACE CONDITIONS OF THE LONGITUDINAL STEEL ARE SHOWN TO HAVE LIMITED INFLUENCE ON ULTIMATE SHEAR RESISTANCE. /ASCE/

• Supplemental Notes:
  • Vol 96, No ST 6, PROC PAPER 7338. PP 1069-1091, 14 FIG,
• Corporate Authors:

  American Society of Civil Engineers

  345 East 47th Street
  New York, NY  United States  10017-2398
• Authors:
  • Swamy, R N
  • Andriopoulos, A
  • Adepegba, D
• Publication Date: 1970-6

Media Info

• Serial:
  • Journal of the Structural Division
  • Volume: 96
  • Issue Number: ST6
  • Publisher: American Society of Civil Engineers

Subject/Index Terms

• TRT Terms: Beams; Bonds; Concrete; Deflection; Failure; Fracture mechanics; Reinforced concrete; Shear strength; Strain measurement; Tension
• Uncontrolled Terms: Concrete beams
• Old TRIS Terms: Arching effect; Diagonal tension; Shear failures
• Subject Areas: Bridges and other structures; Highways;

Filing Info

• Accession Number: 00209235
• Record Type: Publication
• Report/Paper Numbers: No. 7360 Proceeding
• Files: TRIS
• Created Date: Aug 17 1970 12:00AM