Evaluating Environmental Impacts of Pavement Design: A Life Cycle Approach to Reducing CO2 Emissions

Abstract: This study investigates the environmental impacts of nine different pavement sections using Life Cycle Assessment (LCA) methodology, with a focus on CO2 emissions. The research highlights the significant role of pavement design choices (materials and thickness) in determining environmental impacts, particularly in terms of global warming potential. The original pavement design resulted in 673,831.61 CO2 eq, while an optimized all-asphalt design demonstrated a 40.49% reduction in emissions, producing 400,990.04 CO2 eq. The study found that the use phase is the dominant contributor to CO2 emissions in a pavement's life cycle, with a staggering 2,091,821,548,074.10 CO2 eq across all designs. Construction and maintenance processes also contribute notably, with embodied effects, including raw material extraction and transportation, accounting for 336,915.81 CO2 eq in the original design. This underscores the importance of optimizing pavement thickness and material combinations to minimize construction emissions. Asphalt-based pavements consistently produced lower CO2 emissions compared to concrete-based pavements. For example, concrete pavement generated 222,174.3 CO2 eq more than the original design, a 32.97% increase, largely due to the high CO2 emissions from cement production. The study also emphasizes the critical impact of pavement thickness on environmental outcomes. Thinner cross-sections generally resulted in lower emissions, with the thinnest concrete design emitting 4.12% less CO2 than the original design. Conversely, the thickest asphalt design emitted 10.76% more CO2 than the thinnest concrete section. By optimizing material choices and thickness, significant reductions in CO2 emissions can be achieved, contributing to the broader goal of environmental sustainability.