Title:
A Fire Resistance Dilemma
Author(s):
William L. Gamble
Publication:
Concrete International
Volume:
30
Issue:
4
Appears on pages(s):
63-67
Keywords:
ACI 318; fire endurance; load factor; strength reduction factor
DOI:
Date:
4/1/2008
Abstract:
In ACI 318-02, load factors for reinforced concrete were reduced, but there was not an accompanying reduction in the ?-factor for calculation of flexural design strength of tension-controlled sections. The obvious result of this change was a reduction in the ratio of service load moment to design flexural strength for these types of members. The not so obvious result of this change was a reduction in the calculated fire endurance of these members. The magnitude of the reduction in calculated fire endurance and discrepancy between calculated fire endurance and tables for fire endurance found in ACI 216.1 are discussed.