The source of new building materials can serve as the demolished concrete buildings

< back04.10.2013

"Instead of transporting materials from a distance , we can use as raw local building to be demolished", says Francesco Di Maio (Francesco Di Maio), a researcher at the Delft University of Technology in the Netherlands.

In addition, he co-ordinator of the EU-project called "C2CA" and aims to develop technology of recycling old concrete buildings.

C2CA project was founded in January 2011 in collaboration with the 13th international partners. Its main objective - the development of environmentally safe and cost-effective manufacturing processes of recycled concrete components and methods of disposal of the buildings at the end of their service life.

How does this work

Concrete mainly consists of two components: the cement in the form of silicates and mixtures of sand, small stones and pebbles 2 centimeters in diameter. Processing includes the separation of these components.

"The main objective of the program C2CA is to break the link that binds the ingredients to use them again", says Di Maio.

Although the scheme is simple, its implementation is not. "We wanted to develop a process that would be attractive in terms of cost. Decomposition by washing away - too expensive and inefficient in terms of ecology", says the expert.

The technology they have created and developed, called Advanced Dry Recovery. "Dry recovery" uses ballistic effect - the materials are subjected to acceleration 1,000 G, in which sand and dust is separated from the stones.

This technology brings the process of manufacturing the components of concrete rubble on the level of economic efficiency that can compete with the extraction and processing of raw materials.
Ironically, their biggest rival in the Netherlands - a very cheap fossil raw material obtained by dredging the river Meuse. However, where the new technology has the advantage of purity, and hence the product quality.

Concrete as an environmentally friendly product

"Few customers wish to detect inclusions in the concrete wall of the pieces of wood", says Di Maio. "While today begin cleaning technology improved, even when using optical monitoring methods our concrete made by recycling, better mechanical properties than the product of the primary components".

Used a second cement has another exceptional dignity, environmental - during roasting in the oven it does not emit carbon dioxide into the atmosphere. "If the process secondary cement, it does not contain CO2", explains Di Maio.

New technology has reached the stage of laboratory experiments and has been tested on a construction project in Groningen, The Netherlands. During the construction of high-rise concrete garage was used by 20% derived from two previously demolished high-rise buildings on the same site.

The technology of the future?

What is the prospect of a new technology for widespread adoption? It is difficult to talk about it, but the fact that there was technology shredder life of concrete structures is important in itself, says Douglas Mulhall (Douglas Mulhall), a researcher at the Agency Environmental Protection Encouragement (EPEA) in Hamburg, Germany.

"As more and more buildings must be designed with the possibility of disassembly, it will be important to demonstrate that this material is able to compete. Otherwise, it will be replaced with steel and other materials that are easier to use when removing" says Mulhall.

The accumulation of construction waste is an increasing problem. Over the last century new towns have grown in size several times, and today the issue of recycling of old buildings is very serious, said Ben Dezark (Ben Dezark), of the Institute of Cradle to Cradle Products Innovation of San Francisco. He has no doubt that in the future without the project process utilization of the building at the end of life, it will not be built.

However, the fact that the technology of concrete for later use at least timely, assured all the experts we interviewed. "It will be a matter of survival for a particular industry", Sure Douglas Mulhall.

Source: boyko.ru