Cast Concrete: Ancient Material/Evolving Technology
Concrete has been known since antiquity. The Romans created the first effective concrete when they combined cementitious materials found near the volcanic caldera from Pozzuoli, a Roman colony in Greece established in 194 BC, with aggregates, sand, lime and water resulting in a chemical reaction achieving a structural and durable loadbearing material. This early concrete made the cupola of the Pantheon, the first real concrete dome possible. The Colosseum and Pantheon are monuments to the longevity of the material, its robust strength and its versatility of form. The 20th century modernists, led by Le Corbusier, started a structural revolution, using concrete to create columns that freed up space and reduced the need for load-bearing facades. In their quest for “honesty” and “economy” of materials they invented a universal language of design. Later masters including Louis Kahn and Tadao Ando continued the dialog, employing cast concrete to create cultural temples for our own time.
All concrete cast in molds is by generic definition cast concrete. However, there are many “recipes” for cast concrete based on the type and proportion of the elements of which it is made. Aggregate, typically rock, sand or gravel ground to fine particles, today may include a wide range of industrial and recycled materials, sometimes reduced to nanoparticles. Growing experimentation with different kinds of aggregates and their application has resulted in cast concrete with new structural properties and formal possibilities.