[M]ost of our structures in the past consisted of individual members having relatively small transverse dimensions as compared with their length, and… - Eduardo Torroja

Before a man can successfully plan a structure... he must study, from every possible angle, the ultimate purpose of his building. Attention must be directed to the basic structural concept before the mathematical process of calculation is undertaken.

Concrete presents, besides a coefficient of , a coefficient of hygroscopic dilation which is more appreciable. While concrete is kept wet... it expands; and as it dries, it contracts, in inverse proportion to the hygroscopic degree of the ambient air. ...The shrinkage ...will vary with the porosity of the concrete and with the thickness used in the structural member. ...Shrinkage is much greater in structures consisting of thin elements subjected to intemperateness of dry climate, and disappears or becomes negligible in underground structures (e.g., foundations).

[T]here are three different but interconnected conceptions to be considered in every structure, and in every structural element involved: equilibrium, resistance, and stability.