Roadscience - How Green?
Cold-in-place recycling of failed pavements
optimizes use of in-place materials, relieving
pressure on virgin aggregate extraction sites,
on landfills, and greatly reduces truck trips
with benefits to air quality, congestion, noise
and reduced resource consumption.
by Tom Kuennen, Contributing Editor
Calculators help predict the environmental
impact of roadbuilding projects
ew tools keep appearing to help the highway,
road and bridge community determine the
environmental impact of the infrastructure they
design and build.
Last month we looked at the proliferation of environmental certiﬁcation programs available for highways (see
Roadway Environmental Ratings:What’s Best for Your Agency?, November
2012, pp. 21-27). But in addition to these guidelines for a
holistic summation of the environmental sustainability of a
project, a plethora of environmental calculators now exist
for a road builder to use in determining project sustainability in advance of construction.
These software-based eco-calculators allow an array of
variables or “inputs” about a project – such as dimensions,
materials, quantities, haul distances and equipment – and
kick out data such as quantities of carbon dioxide emitted
in construction or over the life of a project, other emissions
18 December 2012 Better Roads
and more. These data can provide a user with multiple
paths to a sustainable project. In doing so a planner gets
hard data projections he or she can use to justify or defend
a project against those who would oppose it.
These calculators can be used in advance by an agency
to establish project fundamentals, by a contractor to pose
environmental alternatives that will favor his capabilities, or
by consulting engineers to assist their agency clients.
For example, at the October semiannual meeting of the
Asphalt Recycling & Reclaiming Association, Donald M.
Matthews, P.E., of Pavement Recycling Systems in Riverside, Calif., said contractors can use the value engineering
process – using environmental sustainability calculations –
to suggest to clients that an alternate (in this case, cold-inplace recycling) could save time and money for a client.
“Use the calculations to suggest and prove that an alternative method will save an agency money, while providing