Design of Short Columns Subject to Axial Load and Bending - Design of Reinforced Concrete - page 315

Problems with SI Units
Column interaction curves are not provided in this text
for the usual SI concrete strengths (21 MPa, 24 MPa,
28 MPa, etc.) or for the usual steel yield strength
(420 MPa). Therefore the problems that follow are to be
solved using the column curves for 4000 psi and
f y 60,000 psi. These diagrams may be applied for the
corresponding SI units (27.6 MPa and 413.7 MPa), just
as they are for U.S. customary units, but it is necessary
to convert the results to SI values.
In Problems 10.28 to 10.30 use the column interaction
diagrams in the Appendix to determine P n values for the
short columns shown if

Problem 10.30

c f

c f 28 MPa and f y 420 MPa.

Problem 10.28

In Problems 10.31 to 10.33 select reinforcing for the short
columns shown if 27.6 MPa and f y 413.7 MPa.
Remember to apply the conversion factor provided be-
fore Problem 10.28 when using the interaction curves.
Problem 10.31 ( One ans. 4 #29)

c

f

Problem 10.29 ( Ans. 1855 kN)