Concrete is the earthly material. The artificial stone that constitutes the foundation of modern architecture is also the material of which the building is made, when neither transparent nor organic. The compactness of concrete, which conceals the tangle of iron nerves and remains impassive as it absorbs all the structural stress, has been appreciated by architects in varying degrees. All too modest, it was only accepted by advocates of a rough or poor architecture. The utilitarian nakedness of concrete, with its austere presence in the streets, has for decades provided cities with a neutral canvas for graffiti. But in the same way that stone, cement does not withstand paint. Like granite, it prefers to age in moss and lichen.

A shapeless material, for a long time it derived excellence from the grain of its gravel, or from the streak or vein of the formwork; from the reference to the industrial process which was so important to the moderns, from the mark of its origin. But the poetics of the formwork came to pass and concrete became a discreet, unromantic product ever more obedient to calculation and quality control. And Swiss concrete became, like chocolate, a standard product, clean and always well executed, the pride of correct and solid civil works...[+]