Classification of reinforced concrete rectangular sections by design criteria of compression, interpolations and deflections (instruction EH-73)

Abstract

In every case of design of a reinforced concrete rectangular section element, it is possible to readily determine two quantities, which taken as x-y coordinates will define a point, these numbers being taken from the initial Information previous to the actual calculations. The position of such point in the plot indicates the equation system to be used in the calculation of the section. When compatibility occurs there are four possibilities: compression (single of multiple), interpolated compression, interpolated deflection and deflection (single or multiple). To each of these possibilities corresponds a given finite or infinite space in the plot In order to obtain the limits of these spaces, one must first chose the ρ = coefficient of the reinforcement covering. s_c = concrete ultimate modulus. Almost all common design and calculation cases are grouped as follows: I. Determination of a section where the width b is known and the height d is unknown. II. Determination of sections where both b and d are known. If the ρ and s s_c values have been previously established, each of the above groups will have its own given plotted graph.