Building walls with demolition waste: the poetry of cyclopean concrete
Ancient Cyclopean walls were built by stacking rough stones, leaning on each other, without the use of mortar. The name derives from the Cyclopes, the giants of Greek mythology, as their construction required seemingly superhuman effort due to the weight and difficulty of lifting and installing each piece of wall. Cyclopic concrete, in turn, mixes this ancient constructive technique with contemporary materials and techniques. What distinguishes it from traditional concrete is essentially the size of the coarse aggregate, which is traditionally made up of stones but can also include remnants of brick or concrete. Our Projects section includes examples of this constructive technique which, unlike the Cyclops, clearly bears the traces of the workers who built it. We spoke to Rafic Jorge Farah, from the São Paulo Criação office, about his experience with this technique in recent work.
In the case of House in Pombal Street, rubble from the previous demolition became the main raw material for the new walls. Constructively, the technique is also similar to traditional reinforced concrete: a wooden mold is used to receive liquid concrete with voluminous aggregates, while maintaining the appearance of the different materials used in the previous composition. According to the project description, “Each wall ended up with a different texture as we imagined ways to build them. Some have been painted, some have not – all contain memories of what once existed.”
They are living walls, full of information. This surprises passers-by and perhaps makes them reflect on the obvious durability present in these rubble walls, reminiscent of the old house.
Pieces of the past
In fact, part of the project’s memory is often mentioned by Rafic as the inspiration behind the use of cyclopic concrete: “As a boy, I witnessed a series of demolitions in São Paulo. At that time, my father set up his first restaurant with the remains of the mansions on Angélica and Consolação avenues (in São Paulo), which were being expanded. Later, in Italy, I looked at these houses built on ruins and with ruins. How many stories like mine have these buildings witnessed? Ruins of various ages.”
What if these fragments brought other fragments of stories they witnessed, of people who left and many more who live there? And if this archaeology, as if in these walls with materials reused again and again, brought many voices, many images?
The role of work
According to the architect, another important factor in this construction technique is the pedagogical aspect and the way in which manual work has become a protagonist of the process. “(Receiving the constructive technique) was a lot of fun. The workers were surprised, but learned quickly and then began to separate fragments to highlight them in certain spaces. Soon things took on a life of their own; I showed up at the job site to see what they had created.
Construction as an agent of change
Asked about how the construction sector can be a vector of change at a time when we must be aware of the environmental impact of our choices, Rafic brings an interesting point of view: “First, (it is necessary for the architect) to understand the construction and – it seems absurd to have to say this – the most important thing is to meet people who will work on the site. These people have stories, and we tend to move on to next to them without paying too much attention to it. They have built this city that we have been living in for a century now. First, the industry must be humanized, then it must become sustainable.”
But such a choice of project can also represent a reduction in its environmental impact. In this case, the method put an end to dozens of potential trucks circulating and unloading rubble in the city, as well as many more that should have brought bricks. Cost, time and fossil fuel pollution have all been avoided.
Rubble, stone, wood, concrete and the crystallinity of glass. One material complements the other. Some demolitions are necessary, but most are a waste of energy. They neglect the efforts of many people, as well as the raw materials extracted from nature, inevitably returning them to the environment as waste.
In addition to being sustainable, reusing materials helps keep history alive, as Rafic says. Reduce, reuse and recycle: the construction industry must change (and has already done so) to adapt to current needs. Various materials can have a much more interesting afterlife rather than just being thrown away as trash. As the concept of urban mining implies, many raw materials are no longer in their original state, but in new anthropogenic deposits, especially in buildings. Considering the built stock of our cities as intermediate repositories of materials can contribute to greener building practices.