Title: Concrete Q & A: 318-02 Questions

Author(s): Gary Klein and Robert Frosch

Publication: Concrete International

Volume: 25

Issue: 8

Appears on pages(s): 100

Keywords:

DOI:

Date: 8/1/2003

Abstract:
1. Can the live load L in ACI 318-02 Eq. (9-3) to (9-5) be reduced by the “normal” procedures given in the model codes, even if the load factor is reduced to 0.5 per9.2.1(a)? Or does the change in load factor from 1.0 to 0.5 already account for a “normal” live load reduction? 2. We are interested in using nonprestressed, deformed reinforcing bars with fy = 95,000 psi (655 Mpa). ACI 318-02 Section 3.5.3.2 allows this provided the strain is limited to 0.0035 at this specified yield stress. Section 9.4, however, limits the yield strength for design to fy = 80,000 psi (550 Mpa) for nonprestressed reinforcing bars. What is the limit of 80,000 psi based on? Is the committee currently studying reinforcing bars of yield stresses greater than 80,000 psi?