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Shear Strength of High-Strength Concrete Walls and Deep Beams.


pdf icon Shear Strength of High-Strength Concrete Walls and Deep Beams. (1320 K)
Duthinh, D.

NISTIR 6495; 19 p. May 2000.

Available from:

National Technical Information Service (NTIS), Technology Administration, U.S. Department of Commerce, Springfield, VA 22161.
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Order number: PB2000-108049

Keywords:

concretes; beams; building codes; cyclic tests; deep beams; high strength concrete; shear strength; shear walls; walls; static tests

Abstract:

In the last 30 years, the compressive strength of concrete that can be produced reliably in the field has more than doubled, from 35 MPa (5000 psi) to 85 MPa (12000 psi). Strengths as high as 140 MPa (20000 psi) can be achieved in the laboratory and, on rare occasions, in the field. Recently, the American Concrete Institute Subcommittee ACI 318-E (Standard Building Code, Shear and Torsion) set up a small working group, which included the author, to investigate barriers to the use of high-strength concrete related to shear strength provisions and to propose appropriate changes to the building code. This report starts with a review of current shear strength provisions in ACI 318-99 for walls and deep beams. In light of recent tests, the author recommends lifting the ceiling of the square root of concrete compressive strength from the current value of 8.3 MPa (100 psi) to 11 MPa (130 psi) for code provisions that govern the shear strength of deep beams. However, there are insufficient data to propose any change to the current provisions governing the shear strength of walls.