Shear Strength of High-Strength Concrete Walls and Deep Beams.
Shear Strength of High-Strength Concrete Walls and Deep
NISTIR 6495; 19 p. May 2000.
Available from: National Technical Information Service
(NTIS), Technology Administration, U.S. Department of
Commerce, Springfield, VA 22161.
1-800-553-6847 or 703-605-6000;
Order number: PB2000-108049
concretes; beams; building codes; cyclic tests; deep
beams; high strength concrete; shear strength; shear
walls; walls; static tests
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.