Life Cycle Assessment and Circularity Indicators of Earth-Retaining Walls and Mechanically Stabilized Earth

Abstract

Although there has been a notable increase in Life Cycle Assessment (LCA) studies in civil engineering, the field of Mechanically Stabilized Earth (MSE) with geosynthetics remains relatively underexplored. This research aimed to perform LCA together with a circularity analysis of countries that could represent the South American context. The materials and methods section covers an environmental analysis using LCA, spanning the manufacturing phase to the end of the structures of MSE with different geosynthetics, comparing Earth-Retaining Walls (ERWs), employing the ReCiPe method. Material circularity analyses for the three structures under consideration were performed using the Material Circularity Indicator (MCI). The proposed scenarios were conducted not only when recycled materials were introduced to replace virgin materials, but also when examining the concrete face and incorporating vegetation planting. The results suggest that MSEs can be environmentally more sustainable than ERWs. Therefore, the decreases were 80%in almost all categories. Furthermore, the material circularity analysis indicated that the incorporation of recycled materials increased the MCI, achieving 250% circularity for geosynthetics. Thus, it was inferred that the LCA methodology and circularity analysis effectively enabled qualitative and quantitative assessments. Notably, the findings highlighted the superior environmental sustainability of soil structures compared to their concrete counterparts.