Architectural concrete

Architectural concrete began to be used very early on, with the first projects by François Coignet, who patented this "artificial stone" in 1869. Highly decorative cladding elements were produced in gray or colored concrete, in wooden molds, for bridge cladding. Auguste Perret's exemplary creations also highlight the aesthetic appeal of concrete, creating contrasting smooth and rough surfaces on the very structure of buildings. Lloyd Wright, in his Los Angeles houses, sought to reveal the "secrets" of the material by working intensively on the surface aspects of facade blocks that were more or less bathed in sunlight.

Modern architecture, driven by the growing need for housing, made little use of these early surface treatments. Instead, it favored rationalism and industrialization, and sometimes eliminated many details that were important to the durability of the structure (water drips, cornices, overhanging window sills, etc.), leading to premature aging of facades.

At the time, the material was criticized for its cold appearance, linked to the emergency architecture – described as rectangular, rigid, abstract or gaunt – often associated with post-war housing estates.

In an attempt to "humanize" the appearance of concrete, a number of architects and visual artists have worked on its aesthetics, offering a whole range of innovative surface treatments and creating what is now known as architectonic concrete.

Architectural concrete can be produced using four distinct techniques: general shape of the element, surface textures or modenations, colors and aspects (washed or deactivated, sandblasted, bush-hammered, polished, shot-blasted, acid-etched, etc.). The architect uses these different possibilities to design façade, cladding and decorative elements, either load-bearing or directly associated with the structure of the building. These elements can be used in both the building and civil engineering sectors, as well as in the creation of urban or landscaped spaces.