[S]tresses in one direction produce not only a deformation along this direction but also transversally, the relation of both being expressed by the s… - Eduardo Torroja

In general, these phenomena are very easy to perceive and understand, but difficult to calculate. The danger of failure increases rapidly with decreasing depth or thickness of the structural member...

[E]very structure has a resistant function to fulfill... to ensure ...the static equilibrium of the structure for a long period of time.

Lightweight concrete obtained with special admixtures producing bubbles throughout the mass shows lower resistance, which makes it less suitable for structural purposes; its practical application is limited to smaller structural elements adequately reinforced in which thermal insulation is required.