The Civil Engineering Contractor February 2018 | Page 24

INSIGHT
Demolition waste is a treasure trove when it comes to
recycling for construction and fulfilling ‘green’ criteria.
Déjà vu building
By Kim Kemp
Construction debris and other recyclables are getting a new lease of life as they are
incorporated into concrete and road-building materials, to lower the CO 2 footprint and
create sustainability.
T
he many benefits of recycling
the most widely used building
material are still largely
being ignored globally, according to
Bryan Perrie, MD of The Concrete
Institute (TCI).
Perrie says 8-billion tons of concrete
are used annually — twice as much
as any other building material. “This
means that the volumes of construction
and demolition waste (C&DW) also
reach substantial volumes. In Europe,
22 - CEC February 2018
for example, the annual volume is
estimated to be around 510-million
tons, in the US it is 325-million tons,
and in Japan, 77-million tons.
The totals for China and India —
where half of the world’s concrete is
produced — are not known. Enormous
volumes of C&DW are ending up
in landfills, completely ignoring their
recycling potential.”
Yet, the demolition of in situ,
precast, and tilt-up reinforced
concrete can be achieved relatively
easily by modern cutting, breaking,
and lifting equipment. Once
demolition of post-tensioned concrete
has been completed, the concrete and
reinforcing steel can also be separated
for recycling.
“The use of recycled concrete as
an aggregate for concrete mixes will
cut the carbon dioxide emission
of concrete, as well as reduce the
depletion of natural resources and