Top 15 Eduardo Torroja Quotes

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.

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).

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.

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.

Adobe (sun-dried clay bricks) is a material usable in regions where sandy clays suitable for fabrication are found. Adobe masonry, is, however, useful only for walls and structural elements subjected to lower values of tension and compression, and is, therefore, of little interest as a structural material.

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.

[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.

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...

If you lean on a straight stick... [it] can resist your weight, despite its slenderness, as long as it remains straight; once it starts to bend, it will easily break. The danger of breaking increases with the deflection... [T]he danger of failure will diminish with the increased of the cross section, or if the same are of cross section should be maintained, by distributing the material in a hollow section.

Even children know that drafting rule is easier to bend flat than across the edges; and... they will not be much surprised if told that for the same width of the rule its resistance is proportional to the square of the thickness and the deflection is inversely proportional to the cube of the thickness. Nevertheless some modern designers seem to be unaware... since they require... beams of such slenderness that they resemble springboards...

[M]ost of our structures in the past consisted of individual members having relatively small transverse dimensions as compared with their length, and in such members stress analysis is much more simple. ...[M]any modern structures consist of frameworks of this type, and frequently the word "structure" refers specifically to assemblies consisting of linear elements.

[E]xperimental investigation of stresses in a plane structure is of great interest and merit as applied to shells with single curvature (barrel shells, pipes) and to shells with double curvature (domes, etc.). In these structures similar states of stress are produced and can be determined at any point as acting in a plane tangential to the center layer of the shell.

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...

[S]tresses in one direction produce not only a deformation along this direction but also transversally, the relation of both being expressed by the so-called Poisson ratio. However, the consideration... is of no great importance for the first, approximate judgement.

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.