‘What actually is concrete? Basically, concrete consists these days of cement, water and a stone aggregate: cement, a hydraulic-setting binding agent, produces a cement paste when mixed with water, which is then enriched with a stone aggregate. The paste envelopes the small pieces of stone, fills the hollows and makes the wet concrete workable, until it hardens through hydration. The concrete then stays rigid, even under water and has a stable volume.
‘Reinforced concrete has led to a revolution in architecture. Steel possesses a high tensile strength, unlike concrete, and therefore makes large spans possible, without the need of arching. Its image as a cold and inhuman material was particularly prevalent in the 1970s. The repetitive way the elements were put together and monotonous housing silos contributed to this, as well as the way in which exposed concrete ages, often perceived as unaesthetic. ‘Béton brut’ architecture led to the term ‘brutalism’. The association of brutality always accompanies the term, which makes the image of exposed concrete quite clear.
‘But reinforced concrete was made famous much earlier through its delicate and highly elegant use in the shell constructions of Heinz Isler (Swiss building engineer, 1926–2009) and the bridges of Robert Maillart (also a Swiss building engineer, 1972–1940). The Isler system is still used today for working out shell constructions. Ulrich Müther realised numerous shell constructions in the 1960s in Mecklenburg-Western Pomerania, which, today, have an almost cult status.
‘Over the course of decades, the volume of concrete and the amount of the material used has been continually reduced, thanks to better calculation methods and formwork techniques. But concrete hasn’t only proved itself as a material for static substructures: colour pigments, additives and new techniques in working the surface have seen exposed concrete enjoy a renaissance for some time now, and it is being used more and more as an architectural skin: façades, floor surfaces, furniture – the possibilities of application seem to be endless.’
– Susanne Fritz – ‘The Independant Resource For Architecture and Design’