Study on CO2 Emission through the Life Cycle of Highways

The energy consumption and green house gas generated from the whole life cycle of highways were studied in this paper. The life cycle of highways was divided into four stages-manufacturing of construction materials, construction, maintenance and the demolition stage. The most energy was consumed in the manufacturing stage of construction materials, which accounted for 52.49% of total energy consumption, and followed, by the maintenance stage that is 43.5%. Gas emission in each life cycle stage includes those from energy production and consumption. And gas emissions in the stages of energy consumption are much more than that in the stages of energy production. CO2 emission from the manufacturing of materials is up to 53% of total emission through the life cycle of highways, the second is that from the stage of maintains. The study shows it is effective measures for reducing environmental load in the life cycle of highway to reduce the use of construction materials and improve efficiency of engineering machinery.