Technical solutions for reducing CO₂ footprint in MSE wall constructions

Terre Armée, Technical department, 92500 Rueil-Malmaison, France

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

Today, the construction industry is one of the most CO₂-emitting sectors. Actions have been taken for several years to reduce these emissions, but progress is still being made to reach the global greenhouse gas emission reduction targets. Reinforced earth walls are mainly composed of a facing made of concrete or welded mesh panels with a backfill reinforced by metallic or geosynthetic elements. This article deals with the proposal of technical solutions to reduce each component’s carbon footprint of a reinforced earth wall (facing, reinforcement, backfill) and to estimate the CO₂ emission reduction at the construction project level (calculations based on a specific and real construction project). Concerning the concrete panels, the replacement of ordinary Portland concrete by low-carbon concrete is a key parameter in the reduction of CO₂ emissions of the construction of a reinforced earth wall (estimation of reduction between 15% and 30% on the total CO₂ emission for this project). Regarding the backfill reinforcement, using geosynthetic reinforcement instead of steel reinforcement is also a way to reduce CO₂ emissions. Indeed, steel reinforcements accounts for around 20% of total CO₂ emissions for this project while geosynthetic reinforcement accounts for around 5%. Finally, regarding backfill, its carbon impact represents about 45% of this project’s overall CO₂ emissions, considering the materials and their transportation. Thus, using recycled materials as backfill and reducing transportation distance are essential.