Research on the carbon neutralization of hot mix asphalt pavement based on life cycle assessment theory

Abstract

The goal of reducing carbon emissions in the field of road engineering has become an important deployment strategy. Based on the life cycle assessment (LCA) theory, the environmental impact assessment and analysis of hot-mix asphalt pavement were carried out in this work on the basis of collecting and investigating the environmental load list data of hot-mix asphalt pavement. According to different life cycle stages, corresponding carbon neutralization schemes were proposed, and the optimal carbon neutralization schemes at different stages were obtained by simulation using queuing theory. The results showed that in the whole life cycle of hot mix asphalt pavement, the construction stage had the highest energy consumption and carbon emissions compared to the other stages, and its global warming potential (GWP) and Chinese abiotic depletion potential (CADP) were also the highest, with the greatest impact on the environment. Compared to other stages, the repair and demolition stage had the smallest contribution to the GWP and CADP evaluation indicators. In the material production stage, the ASRT 5A zeolite adsorbent had the best adsorption effect on carbon dioxide gas. The carbon emissions generated during the production phase of the neutralization material required an ASRT 5A zeolite adsorbent of about 83 kg. Michelia chapensis exhibited the best carbon dioxide purification effect compared to the other three trees during the transportation construction and maintenance disassembly phase. Michelia chapensis required a leaf area of about 28,016 m2 to neutralize the carbon dioxide emissions generated in these two stages.