Technical, Economic, and Environmental Trade-Offs in Pavements with Lime-Stabilized Soils: A Sustainability-Oriented Approach

Abstract

This paper proposes a sustainability-oriented approach to evaluate the incorporation of lime-stabilized soils into pavement systems as a strategy to reduce the environmental impacts associated with conventional unbound granular structures. Pavement sections were designed for three tropical subgrades (Argisol, Latosol, and Luvisol), considering five traffic levels ranging from low to high. Soil–lime layers containing 3% and 5% calcitic hydrated lime were compared with conventional unbound granular sections. Pavement design was performed through a mechanistic–empirical approach. Environmental impacts were quantified using life-cycle assessment from a cradle-to-construction perspective, including midpoint and endpoint indicators, and assessed together alongside relative construction costs. Pavement sections incorporating soil–lime layers reduced environmental impacts and relative costs for low and intermediate traffic levels, particularly for Argisol and Latosol subgrades. Reductions in global warming potential reached approximately 48%, while endpoint damage reductions exceeded 60% in some scenarios. However, the environmental benefits became progressively less pronounced as traffic levels increased. For the Luvisol subgrade, the lower suitability for lime stabilization required an additional graded crushed stone layer, reducing the environmental advantages of the stabilized systems. Soil–lime stabilization can represent an environmentally advantageous and economically competitive alternative for pavement design in tropical regions, particularly under low-to-moderate traffic conditions, although benefits may also be achieved at high traffic levels depending on subgrade characteristics.