Title:
Shear Design of High- and Normal Strength
Concrete Beams with Web Reinforcement
Author(s):
Kaiss F. Sarsam and Janan M. S. Al-Musawi
Publication:
Structural Journal
Volume:
89
Issue:
6
Appears on pages(s):
658-664
Keywords:
ductility, high-strength concrete; shear properties; span-depth ratio; standards;
web reinforcement.
DOI:
10.14359/9644
Date:
11/1/1992
Abstract:
This work examines 14 beams with stirrups failing in shear, in addition to 107 from the literature. These include high-strength concrete (HSC) beams with compressive strength of f,’ > 41.4 N/mm2 (6000 psi), and normal strength concrete (NSC) beams with lower f,’ values. It is shown that using ACI Building Code Eq. (1 I-6) for concrete contribution is conservative for both HSC and NSC over a wide range of the principal variables: concrete compressive strength; stirrup nominal strength (p, f,); longitudinal steel ratio (pW); and shear span-to-depth ratio (a/d). However, a higher coefficient of variation (COV) is obtained using the more conservative Canadian code simple design alternative. The latter ignores the influence of pW and a/d on concrete contribution in a way similar to ACI Eq. (I l-3). A proposed design method is also conservative with a lower COV than ACI Eq. (1 l-6). Design by either of these two methods shows no drop in the safety factors with rising f,’ [up to 82.9 N/mm2 (12,000 psi)] and pw (over 4 per-cent). However, when a/d ratios exceed 5 or when p,f, values are high, both methods (ACI and proposed) give lower safety factors.