Colorado’s concrete paving industry is committed to reducing
Greenhouse Gas (GHG) Emissions in Colorado and around the world.
The concrete paving industry has identified three Stages of
Opportunities for Reducing Greenhouse Gas (GHG) Emissions:
Before Construction, During Construction, After Construction.
Reducing GHG Emissions Before Construction…
Optimizing pavement design and materials selection begins the
process of reducing GHG emissions in the beginning stages of
any pavement’s life. Designing with concrete means designing for
longevity and longevity of pavement life is the primary opportunity
for the reduction of GHG emissions as it allows for less frequent
reconstruction.
The production of cement is often the most referenced item in
regard to CO2 output. One way the concrete pavement and cement
industries have begun addressing this issue is by producing and
using Portland Limestone Cement (PLC) or Type IL. Blending
limestone into the cement reduces the amount of energy required
as well as the amount of CO2 produced. Alternative fuels are also
being used in these plants which burn cleaner than coal and
renewable energy options are being pursued.
Requiring Supplemental Cementitious materials such as Flyash
and Slag Cement utilizes byproducts from coal fire power and steel
production while increasing the durability of concrete pavements.
Specifying optimized gradations reduces the amount of cement
required and the use of recycled concrete can also greatly improve
the opportunity for reduced GHG emissions.
Reducing GHG Emissions During Construction…
Sourcing locally available materials is one of most effective ways to
prioritize sustainability during the construction process. The use of
mobile batch plants decreases the number of trucks hauling long
distances. Having onsite mining operations, 5,200 truck trips can
be avoided when producing 120,000 tons of sand. When recycling
pavement that is removed into 50,000 CY of base 4,200 truck
trips can be saved. All of these contribute to the reduction of
GHG Emissions.
By optimizing phasing of projects, identifying concrete mixtures for
specific situations, and performing nondestructive testing construction can be accelerated which reduces congestion.
Reducing GHG Emissions After Construction…
During its long lifespan, concrete reabsorbs a significant amount of
CO2 through a naturally occurring process called recarbonation.
Pavement preservations and restoration serves the main purpose of
extending the life of the pavement and minimizing disruptions to the
traveling public while maximizing the efficiency of resources.
Diamond grinding is a practice that is often combined with other
Concrete Pavement Repair (CPR) procedures. Diamond grinding can
extend a pavement’s life by 14-17 years per a study performed by
Caltrans. Improved smoothness, texture and reduced noise can all
be anticipated as a result of Diamond Grinding.
Concrete Overlays contribute greatly to pavement preservation and
are a great opportunity for reduced GHG Emissions after initial construction. Concrete overlays efficiently utilize resources and eliminate
the need for disposal of existing pavements. They are cost effective
and are constructed quickly while simultaneously extending the life
of the pavement.
It is imperative to consider all aspects of “use phase” of road construction and identify the areas before, during and after construction
where improvements can be made to create the most sustainable
and reliable roadways possible.
