Carbon uptake of concrete in the US pavement network

Abstract

The impacts of climate conditions, the geometry of concrete in use, and end-of-life and surface treatment actions have received little attention in previous studies of carbon uptake calculation. This work attempts to advance the knowledge of pavement carbon uptake based on a bottom-up approach and using state-level data to estimate the carbon uptake of the US pavements and its associated cost. To do so, a pavement management system model was developed to predict the performance and characteristics of the national pavement network using local maintenance and repair practices and data science approaches. Then, a high-resolution carbon uptake estimation method was applied to this system model. Our results show that 5.8 million metric tons (Mt) CO2 can be sequestered by the US pavement network, of which 52% will be sequestered when the demolished concrete is stockpiled at the end of life. The climate condition and mix design practices in California result in this state having the largest carbon uptake during the use phase of the pavement life cycle, while the end-of-life uptake is larger in those states that have an extensive composite pavement network. Extending the stockpiling period up to 30 years can increase the total end-of-life carbon uptake to 11.8 Mt CO2. The cost associated with concrete stockpiling varies depending on the scenario, but abatement costs for a 1 to 17-year stockpiling timeframe are $25–100/ton CO2, making end-of-life stockpiling a competitive strategy for greenhouse gas mitigation of the road network.