Quantitative Analysis of Carbon Emissions from Highway Construction Based on Life Cycle Assessment

Carbon dioxide (CO2) emissions from the construction of road infrastructure have been of growing interest in recent years. This paper proposes a binary statistical method for highway construction based on project cost control and a construction management system. A quantitative analysis of the CO2 emissions from highway construction activities was also conducted to guide the formulation of a carbon reduction strategy. Taking an expressway in central China as a case study, the CO2 emissions from different construction activities were calculated. The results revealed that the CO2 emissions for the whole construction project reached 10,605.2 t<middle dot>km-1<middle dot>lane-1, with the raw material production and on-site construction phases accounting for 95.2% and 4.8%, respectively. The values for bridge and tunnel engineering were much higher than those for other engineering types. In the raw material production phase, steel and cement production contributed the most to emissions (more than 99%). During the on-site construction phase, diesel and electricity consumption contributed 90% to CO2 emissions, especially from earthwork, subgrade protection, bridge engineering, tunnel excavation, and pavement surfacing. Accordingly, efforts should be focused on the key points and directed toward using recycled and low-carbon materials and improving working efficiency, machinery performance, and construction technology.