Comparative study for global warming potentials of Chinese and Norwegian roads with life cycle assessment

Mitigation of GHG emission is increasing concerned in the research field of road engineering. The quantitative assessments of integral road structural designs in different countries would shed light on the implementation of sustainable road development and global warming controlling. The study referred to the European E6 and the Yanqing-Chongli expressway to quantify the GHG emissions for Norwegian and Chinese roads, and investigate the critical procedures and factors in resulting in the differences of GHG emissions. The data inventory and research framework for life cycle assessment (LCA) were established according to their applied materials, structural design and construction techniques. Moreover, the quantification of GHG emission was conducted as considering the surface layers, base layers, subbase and frost protection layer. The comparative results indicate that the Norwegian road generated extra 1.43 t equivalent CO2 more than Chinese road during the 20-year service life, and the surface layers are the most source of GHG emission in road structure, which occupied 65.75% for Chinese road and 43.19% for Norwegian road. Additionally, the materials extraction phase caused the largest proportion of GHG emission in Chinese road case, while the road construction phase was verified as the capital GHG contributor in Norwegian road case with 108.27 t equivalent CO2 emitted. The obtained results in the comparative study could provide the practical references for low-carbon road construction and promising strategies for globalization development.