Title: Probabilistic Study of Reduction Coefficient for Balanced Steel
Ratio in the ACI Code
Author(s): Kazuyuki Ito and Akinori Sumikama
Publication: Journal Proceedings
Appears on pages(s): 701-709
Keywords: bending; building codes; compressive strength; probability theory; quality control; reinforced concrete; reinforcing steels; strength; structural design;
variations; yield strength.
It is desirable to design reinforced concrete structures to be under-reinforced to avoid the brittle failure of members in flexure. A method of insuring a state of under-reinforcement is proposed that considers, using probabilistic methods, the variations in strength of both reinforcing bars and concrete. The propriety of the reduction coefficient K for the balanced steel ratio pb provided in ACI 318-83 is examined, and it is shown that with the ACI K-values, the probabiiity of P, of over-reinforcement is very high when concrete is placed in situ. K-values having the required reliability are presented also.