Abstract
Cost analysis of singly reinforced concrete beams is performed to determine the influence of cost and design parameters on their optimum design. These parameters are steel to concrete cost ratio, formwork to concrete cost ratio, concrete compressive strength, beam width and span of the beam. The influence of each parameter on the optimum steel content of the minimum cost design is studied. The cost per unit length of the beam represents the objective function to be minimized. The constraints on the optimization model are in accordance with the ACI-Code provisions. The deflection consideration which constrains the minimum depth of beams to a specified lower limit is considered besides the flexural demand due to the imposed loads and the ductility requirements that specify the upper and lower limits of tension steel ra