Concrete’ solutions

The
European Union's construction sector faces a testing target. Under the EU Waste
Framework Directive (2008/98/EC), it must, by 2020, reuse or recycle at least
70% by weight of non-hazardous construction and demolition waste. In some countries, such as Belgium, Germany and the
Netherlands, says the Belgian sustainable development research institute VITO,
the target is already being exceeded. For the EU construction sector as a
whole, however, a 70% reuse and recycling rate is feasible but will "definitely
not be easy".

Fortunately, research is being done into the reuse and
recycling of construction and demolition waste, 380 million tons of which is
produced in the EU each year – more than 30% of total EU waste.

IRCOW, a project supported by the EU's Seventh
Framework Programme, is analysing through five case studies best practice in
management of construction and demolition waste. VITO is a partner in IRCOW
(Innovative Strategies for High-Grade Material Recovery from Construction and
Demolition Waste).

IRCOW started in January 2011, and will run until the
end of 2013. The case studies cover a wide range of situations commonly faced
by the construction industry.

So far, results have been promising. The case studies
in Bilbao and Poland have been completed.

In Bilbao, a building dating from the 1970s with a
concrete structure and a brick facade was cleared and demolished. Steel
reinforcing bars were separated from the waste concrete and bricks, which were
crushed, generating mounds of recycled aggregate.

The Polish case studied the onsite treatment of hazardous demolition
waste, in particular asbestos. The result is that asbestos is, in effect,
burned out of the waste, and the hazardous material is converted into a
non-hazardous material.

The Swedish case study has also been completed as far
as was possible. It was decided not to demolish the old school building for
economic reasons.

The
project has shown that cellular, or aerated concrete (commonly known as breeze
blocks, or Beton blocks) can be recycled. Previously, this was not recyclable
into concrete because it is lightweight and weakens recycled aggregates.

Although not finished, the IRCOW project has shown so
far that there is substantial scope either for the increased reuse of
construction waste (for example, doors and windows), or for its recycling into
low-grade applications, such as aggregates for building foundations and roads.

The main environmental benefits are avoiding the use
of raw materials, and avoidance of waste being sent to landfill. Reuse and
recycling of construction waste can also be cost effective, especially where
there is infrastructure to manage the waste.

The main obstacles to greater reuse and recycling of
construction waste, according to IRCOW, are the technically acceptable use of
recycled materials for higher-grade applications, and trust in products made
from recycled materials.

To ensure that recycled products can be trusted,
certification schemes might be needed, or recycled materials, such as
aggregates in concrete, will need to be incorporated into existing standards.