gravel construction
ECO-construction by the REcycling of Concrete in concrete Materials from the recycling of inert construction waste represent an important and exploitable source of materials. The recovery of all materials from deconstructed concretes, as constituents for the manufacture of new concretes, today opens up new environmental, economic and technological perspectives. Its implementation requires first removing certain scientific and technical barriers.récupération de béton The recovery of demolition concrete in concrete: environmental and economic issues The management of construction waste is an important issue for the construction sector because it must meet the requirements of sustainable development and particularly those related to the environmental impact. The reuse of recycled materials from demolition/deconstruction makes it possible to limit the extraction of raw materials and therefore to participate in the preservation of natural deposits of aggregates, the exploitation of which is increasingly complex and subject to strong regulatory constraints. The recovery of construction waste also makes it possible to limit the energy and environmental impacts linked to transport. It is also an important economic issue because this problem is increasingly present and evaluated in the markets. Concrete is the most widely used construction material in the world , and its ecological impact is enormous: the embodied energy of concrete is 1850 kWh/m 3 . In comparison, that of lumber is 180 kWh/m3. This footprint is due in part to the production of cement, the efficiency of the production plants and the materials used. In this article, it is rather a question of replacing the raw materials of concrete (sand, aggregates) with recycled concrete.Construction professionals, more and more sensitive to issues related to the preservation of the environment, they naturally wonder about the future of concrete at the end of the life of buildings. In particular, we note that out of a total of approximately 300 million tonnes of construction waste produced per year in France, only a small part of the concrete found there is recycled, mainly for road works. However, in other European countries, recycled aggregates from crushed deconstruction concrete are already used in the formulation of new concretes.The ECOREB Project mainly aims to change the trend at national level by lifting the barriers scientists related to the use of crushed concrete aggregates as a constituent of new concretes. This project is Concrete with recycled content: Switzerland at the forefront If we cannot reduce the consumption of concrete in construction, for technical or economic reasons, we should at least opt for greener choices , as Zurich does. In 2002, the city inaugurated its first public building made of recycled concrete, a school in which 80% of the concrete used was reused. Pieces of concrete from demolition and mixed rubble, containing bricks, tiles or plaster in addition to concrete make up the structure of this school! Convinced of the benefits of using recycled aggregates, the Zurich administration set a requirement in 2005 that all public buildings should be constructed using at least 25% recycled concrete . Since then, some buildings have grown further.