Eduardo Torroja Quotes

The variety of exterior forms in concrete is limited only by the cost of forming; and its thickness is limited only by the size of aggregates, gravel, and sand.

Bricks are considered to be the first material created by human intelligence from the four elements: earth, air, water, and fire. ...The great variety of designs and effects that artists of the past, especially the Arabs... were able to create in their brickwork, assembled with an element so monotonous... can be compared only with the beauty and attractiveness a romantic poet attained by adjusting his verses to the rigidity of a formal meter.

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).

[C]onsider the danger of bulging and... counteract it by providing adequate anchorage, thus shortening the free length of the member and reducing its relative slenderness.

Stone can effectively resist compression but is relatively weak in tension. Because of its mass and weight it may be used advantageously in structural types that can be made stable by the proper weight (dead load, gravity) and are but slightly exposed to lateral forces.

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.

The material in all elementary parts of a structure must have the properties of resistence to all internal forces produced by general loading conditions and by the action of any exterior force.

Clay masonry, like concrete, is a "plastic" material that permits the pouring in situ of large monoliths of any shape or form, with certain limitations and by using special methods. Its economical possibilities when used in walls of popular housing, its excellent heat and sound insulation, as well as its aesthetic possibilities, should not be underestimated. Its resistance and durability can be substantially improved by using modern techniques and methods, for example, admixture of small amounts of Portland cement in accordance with granulometric investigation, petrographic composition, and rheological behaviour of all constituents.

Mathematics is merely a convenient tool by which the designer determines the physical proportions and details of a planned structure in order to transform his ideas... to the actuality of a finished structure.

Stress phenomena are... not independent of scale, as was the case pertaining to simple external static equilibrium. ...with increasing dimensions of a structural element the volume and therefore the proper weight increases more rapidly than its cross-sectional areas...

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...

Long before... our techniques of today, men could conceive and build structures adapted to the requirements of resistance... because he had observed... the branches of a tree bending under the weight of fruits and the tensioned cords of strings in which children have rocked from time immemorial...

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

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.

Construction methods are... variable for each specific material.