How is this EPD used?
To apply this EPD to a specific product, the average data provided in the EPD needs to be adjusted to align with the product specifications considering:
a) the substrate,
b) coating thickness, and
c) coating life.
The choice of substrate is particularly important since it has a dominant impact on the results.
The industry average impacts given in this EPD should only be used directly if no further details or specifications of the actual product are known.
Australian steel manufacturers, InfraBuild and BlueScope Steel also have published EPDs for their steel products. When combined with the GAA EPD, InfraBuild and BlueScope Steel’s EPDs ensure the specification of hot dip galvanized steel is fully covered by an EPD, which may provide an improved sustainability benefit for your project.
Aim: To calculate the Global Warming Potential (GWP) impact for a Universal Beam (410UB53.7) for an actual coating thickness of 200 μm in a C3 corrosivity category and a design life of 100 years.
Method: The design life is the controlling feature in this example as the design life of 100 years is less than the calculated coating life of 200 μm/1.4 μm per year = 144 years.
Multiply the EPD results for the specific steel substrate* by the nominal mass of the steel substrate (for 1 m²).
* from the relevant InfraBuild EPD.
3.2 kg CO2e * 53.7 kg = 171.84 kg CO2e or 1.72 kg CO2e/y
Multiply the A1-A3 hot dip galvanizing only impact per 1 kg of zinc coating (Table 7 of the EPD) by the nominal mass of zinc coating identified for the product.
0.128 kg CO2e/y * 0.898 kg = 0.11 kg CO2e/y
Adjust the results per year by considering the design life.
For a design life of 100 years
Substrate (1.72) + Coating (0.11) = 1.83 kg CO2e/y