Implementation of environmental criteria in civil engineering (infrastructure)

Applying Environmental Criteria in Civil Engineering

Steel sheet piles are mainly used for permanent applications in civil engineering, predominantly for infrastructure and foundations, i.e. construction of quay walls, retaining walls, underground car parks, bridge abutments,… Besides, sheet piles are used for temporary applications, such as watertight cofferdams in the water, deep excavation in urban areas, etc. One of the key advantages from a financial and environmental point of view is that they can be driven into the ground and easily recovered after their service life, and either reused several times before being recycled or directly recycled.

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en English Implementation of environmental criteria in civil engineering | 2022.pdf de German Berücksichtigung von Umweltkriterien in öffentlichen Ausschreibungen | 2022 .pdf fr French Intégrer des critères environnementaux dans les travaux de génie civil | 2022.pdf
Example of a fictional discount (credit) allocated to a contractor’s bid im
Example of a fictional discount (credit) allocated to a contractor’s bid
Influence of the assumptions on the EPD LCA results
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Life Cycle Assessment (LCA) and Environmental Product Declaration (EPD)

There are two types of steel sheet piles, hot rolled (HRSSP) and cold formed (CFSSP). Both types can be produced from steel from the primary route (Blast Furnace / Basic Oxygen Furnace – BF/BOF – transformation of iron ore into steel) as well as from the secondary route (Electric Arc Furnace – EAF – recycling of steel scrap into new steel). The embodied carbon of the production of steel sheet piles with steel from the EAF route, such as the EcoSheetPile™ range - see - is much lower than sheet piles from the BF/BOF route, for instance ArcelorMittal’s CFSSP produced from hot rolled coils - see [4]. The new range EcoSheetPile™ Plus, which is part of ArcelorMittal’s XCarb® brand that covers products with a low carbon footprint and ArcelorMittal’s transition to carbon neutrality by 2050, uses 100 % of renewable electricity in the EAF route, thus reducing the embodied carbon by around 30 % compared to the EcoSheetPile range (see Fig. 2 - 370 vs. 520 kg of CO2-eq/t).

Environmental criteria - The Dutch showcase

Some European countries have started using environmental criteria in civil engineering procurement, with the Netherlands leading. They enforce a scheme that prioritizes sustainability through the most economically advantageous bid. Public administrations use a monetization scheme based on multiple environmental indicators from national EPDs or a national database, yielding a single Environmental Cost Indicator (ECI). The ECI, representing materials with significant environmental impact, is subtracted from the project price as a fictional financial bonus. This encourages contractors to invest in R&D, optimize design, and reduce environmental impact. However, the need for "national" EPDs poses challenges for manufacturers operating in multiple European markets.

End-of-Life practices

Steel sheet piles are often recovered after temporary use or end of service life. The initial EPD from 2016 assumed 25% reuse, 74% recycling, and 1% landfill. The revised EPD EcoSheetPile Plus adjusted these rates to 25% reuse and 15% landfill after deeper analysis. Each project should adjust these values in a specific LCA, as reuse and landfill rates can vary significantly. Indirect impacts like traffic congestion, noise, and vibrations are crucial but not easily quantified. The graph highlights differences between EPD data and project-specific LCAs. It shows the importance of considering assumptions for a project, especially Module D, which factors in steel recycling rates and production routes. Reducing landfill rates to 0% can decrease the overall GWP by 15%, while increasing landfill beyond 15% raises it above EPD levels. Despite data gaps, omitting phases with low impact is acceptable for reliable analysis.