A series of nondimensional ultimate load- moment interaction curves for short, rectangular concrete columns with axial prestressing are presented. Several design examples are included to show the application of the design charts. General nondimensional equations are given which are based on nonlinear approximations for both the concrete and prestressing steel stress-strain curves, linear strains across the cross section, strain compatibility and equilibrium. The steel location is generalized by replacement of individual strands with a rectangular prestressed steel tube. The series of curves presented are for a steel strength of 270 ksi (1861.7 Nlmm2), concrete strengths of 5, 6, 7, and 8 ksi (34.48, 41.37, 48.26, and 55.16 N/mm 2 ), and geometric parameters corresponding to the more commonly used columns. In addition, full and partial stressing of the prestressing steel were considered.
