November/December 2022 - 89

is already being implemented in some
such cases in the European Union. The
deep foundations industry needs to
know what its emissions are and how to
reduce them in order to meet these
upcoming requirements, for clients and
for the industry itself. Using the carbon
calculator can help do just that.
Using the Carbon Calculator
To begin using the carbon calculator, the
first thing to do is go to http://www.
geotechnicalcarboncalculator.com and
download the tool and the associated
guide. Then go to the DFI Sustainability
Committee webpage at www.dfi.org
and watch the video the committee
created on how to use the calculator.
The emissions categories in the
carbon calculator tool are:
* Materials, e.g., cement, steel, water
(including transportation emissions)
* Energy, e.g., diesel
* Mobilization/demobilization
* People's transport, i.e., employees
commuting to site
* Assets, i.e., the emissions from
manufacturing the equipment that
should be allotted to the project
* Waste, e.g., transport of waste offsite
* Externally calculated emissions, e.g.,
emissions calculated from certified
environmental product declarations
By using the carbon calculator, the
deep foundations industry can
measure the embodied carbon of
proposed geotechnical solutions and
then purposefully modify designs and
construction plans to reduce the total
carbon emissions.
The tool works by using established
emission factors to convert inputs into
equivalent carbon dioxide (CO2e) emissions
in metric tons. CO2e means that
the mass of greenhouse gas emissions
other than carbon dioxide, e.g., methane,
are converted to a mass of carbon
dioxide using a factor that is based on
equivalent climate impacts. Additionally,
the tool provides the embodied
carbon of the materials and energy used,
i.e., it accounts for all the CO2e emissions
from resource extraction to manufacturing
to when that material arrives on
site. This is called a cradle-to-gate
analysis. As an example, if using Type IL
Portland cement, 1,000 lb (450 kg) of this
cement has incurred 750 lb (340 kg) of
CO2e (or 0.34 tCO2e) emissions before it
even arrives at site.
In many cases, calculating
the quantity of
materials is a useful
place to start. The data in
the carbon calculator
were collected from case
studies that Carbone 4
received from DFI and
EFFC member organizations.
After assessing
the case studies, they
found that for most
techniques in the industry,
materials have the
largest impact on the total carbon
footprint of the solution. This is good
news because material quantities are
the easiest to calculate, both for
designers and contractors, making a
quick carbon calculation based on
material alone a possibility for all
industry members. These types of calculations
are useful for an initial carbon
comparison between different foundation
options.
However, to do a complete carbon
calculation early in a project, or without
information such as how much fuel is
used for a particular technique, Carbone
4 has provided simplified ratios for
many of the techniques and for many of
the categories. These simplified ratios
were created by using the case studies
to determine the average contribution
of the impact categories, besides materials,
for a given technique. This
reasonable and defensible estimate of
the total carbon emissions can be made
even before all the details of construction
have been decided.
The carbon calculator spreadsheet
is set up to calculate emissions for one
project with one technique, one project
with multiple techniques or to compare
different techniques for the same
project. The benefit of running the
calculations for the case where a project
is required to use specific techniques is
that the carbon hotspots can be
identified and zeroed in on to get the
most impact out of carbon reduction
efforts. The benefit of having carbon
calculations when comparing different
solutions for one project is that
embodied carbon can then be used as
part of the decision-making process for
selecting the final solution.
Contribution to total carbon footprint for each emissions category
DEEP FOUNDATIONS * NOV/DEC 2022 * 89
November/December 2022

Table of Contents for the Digital Edition of November/December 2022
