Salwa CHERKAOUI EL BARAKA, Indépendant, France
Each year, 30 million tons of soil are excavated to carry out the construction of the Grand Paris Express. This significant mass of land is now considered as « waste » by the 2014 law, for the only reason of it being moved from its excavated site to another one. Storing, categorizing and protecting these earths is one of the many challenges facing the authorities. But with the growing scarcity of storage places, the reuse of this "waste" is becoming even more essential to generate a new life cycle for it.
The importance of this issue resides not only in the scale of the challenge facing the Grand Paris, but mostly, because it reflects a type of situation many other metropolises are and will be facing around the world. Indeed, in 2050, the number of people living in urban areas is expected to increase by 2.5 billion, an exponential urbanization rate that will demand an equally massive use of raw materials, but also, an increasing amount of earth excavation. Therefore, the following question emerges: can resolving the equation of raw material scarcity and the growing amounts of ‘wasteful’ earths reside in deflecting the way we consider these excavated earths? In other terms, can what we call today ‘waste’ be tomorrow's valuable resource?
This is exactly the challenge that some architects are tackling nowadays in the context of the Grand Paris. After their Exhibition - Experimentation: Terres de Paris, de la matière aux matériaux, Joly&Loiret continues to experiment with the re-use of the excavated earths of the GPE, turning them into clay panels, mud bricks or plasters, and using them in their own architectural buildings. In fine, the challenge the aim is to find an “industrializable” and economically viable process of this transformation.
What can we learn up till now from these experiences? What are the technical and legal challenges that face these processes? And to which extent does it allow to close the circularity loop within the urbanization of the Grand Paris?
Mots clés : Excavated earths |Construction waste |Material reuse |Circular urban planning |Biobased materials
A103300SC