RC116 JanFeb 2025 - Magazine - Page 32
Many of these approaches are commonly used in Canada and
beyond. The lowest hanging fruit is recycling materials. Asphalt is
100 per cent recyclable, as are most of the materials used in road
construction. Recycling asphalt or reclaimed asphalt pavement
(RAP) has three main bene昀椀ts: reduced cost; lower emissions; and
less waste. The numbers are quite compelling. Reaching 40 per
cent of recycled asphalt in mixes would reduce cost by over 23 per
cent reduce emissions by almost 60 per cent and redirect waste
to serve a useful purpose rather than having to build or expand
quarries.
Within Canada, Alberta leads the way. They are trialling in
40 per cent recycled aggregates on Highway 750 just outside
Edmonton. They currently use around 19 per cent recycled
content in asphalt mixes. Other provinces are playing catch-up
with Ontario down at 16 per cent, Quebec 14 per cent, and British
Columbia nine per cent.
There are legitimate reasons for this, but primary among them
is the concern that there is a greater risk of surfaces failing earlier.
Research has shown there is no notable di昀昀erence in lifespan
compared to using virgin materials. South of the border Nebraska
allows up to 50 per cent RAP and their study has shown no
signi昀椀cant di昀昀erence in performance.
This is where industry needs to step up to help build trust and
con昀椀dence by providing transparency around asphalt mixes, and
perhaps looking at tools like extended warranties to overcome
any concerns around recycled materials.
The public sector too can help by looking
at outcome-based speci昀椀cations stating
the length of time a road should last, or at
least work across boundaries to land on a
set number of standard speci昀椀cations for
asphalt mixes rather than demand their
own special mix.
Using cold in place recycling can also
be very impactful. It involves scraping the
top layer o昀昀 the road, processing it, and
reapplying it in one long train. Using lower temperatures and reducing the amount
of truck tra昀케c shipping waste materials
out and brining new materials in can cut
emissions by 44 per cent, according to
Colas research. Studies in the U.S. have
shown typical cost savings of around 20-30
per cent, with the added bene昀椀t of seeing
construction times that are 20-40 per cent
faster meaning less tra昀케c jams. It is used
sporadically in Canada, and a signal from
provinces that they would accept its use
would provide the certainty to invest in
the equipment needed.
COLAS CANADA
TRANSPORTATION
PART OF THE HISTORY OF
CANADIAN INFRASTRUCTURE
For more than two decades, ACCIONA has been helping to build
Canada’s largest and most important infrastructure projects.
From research and development to the design, construction,
operation, and maintenance of large-scale, complex projects,
we’ve invested in the environment, the future, and our
Canadian roots with every step.
Find out more at:
32
RENEW CANADA – JANUARY/FEBRUARY 2025
RENEWCANADA.NET
