Research On The Carbon Dioxide Emission Of Urban Road Maintenance Engineering Including The Construction Activity And Traffic Impact Based On LCA

The transportation industry is one of the key links for China to cope with global warming and developing sustainably.With the process of rapid urbanization and motorization,exploring the influencing factors and its interactions of carbon dioxide emissions of construction and traffic delay from urban road maintenance project is the scientific approach to decrease the carbon dioxide emissions with the increasing demand of China's urban road maintenance.The main work of this paper includes: based on the basic framework of the methodology of life cycle assessment,and considered the influencing factors and interactions of construction activities and carbon dioxide emissions from traffic operations in urban road maintenance projects.Meanwhile,with appropriate mergered and adjusted the content of maintenance based on the interaction characteristics of maintenance sites,disease locations and maintenance types,a common maintenance and preventive maintenance plan for asphalt pavement roads in loess areas under semi-arid climate conditions is formed,and a model of estimating carbon dioxide for semi-arid areas including material production,construction and material transportation stages is constructed based on the construction process of the maintenance plan.Meanwhile,based on the association methodology of VISSIM simulation system and MOVES model,the method of calculating the extra carbon dioxide emission of vehicle operation from the maintenance project including the road of being constructed and vehicle traffic diversion.Undering the maintenance project scenarios,this paper analyzed the characteristics of carbon dioxide emission from the material production,construction,material transportation and transportation stage,and clarify the magnitude and main sources of emissions at each stage,and reveal the impact of maintenance location,disease location and maintenance type on emissions from maintenance project.To explore the interactive effects of urban road characteristics,conservation types,and key factors in the conservation organization program on the lifetime carbon emissions of urban road maintenance projects.Using the data of actual road and traffic operation,this paper found that:(1)For the calculation of the construction case of the maintenance plan in the semi-arid area,it is found that the carbon dioxide emissions from the maintenance of the grassroots and roadbed are high,and the material production is the main source of emissions from construction activities.In minor and medium-sized rehabilitation,the emissions of construction are higher than material transportation,while the result of major rehabilitation is opposite;(2)According to the calculation of urban road maintenance cases with high construction intensity and the preservation of the daytime construction unless retaining two lanes,it is found that:(1)Transportation accounts for 44%-50.82% of the total carbon dioxide emissions,followed by material production accounts for 31.95%-42%.(2)Uncertainty in lime and gasoline carbon emission factors will have an impact on carbon emissions;(3)The extra emissions of vehicles on the construction road accounted for 77%-82% from transportation,while the extra emissions of vehicles caused by traffic diversion accounted for 18%-23%,the effect impact of which could not be ignored.And changing the capacity of construction road has a greater impact on carbon dioxide emissions of transportation;(4)The difference in the position,quantity and length of the surrounding lanes will have a greater impact on the carbon emissions from traffic impacts;(5)Increasing or decreasing the 10% of traffic volume within the scope of construction,the carbon dioxide emissions of maintenance projects will vary between-16% and 57%..The methodology of estimating life-cycle carbon dioxide emission from urban road maintenance project in this paper makes up for the deficiency of urban road carbon emission research at home and abroad,and expands the system boundary of life-cycle carbon dioxide emission research in urban road maintenance stage,which provides effective research in this field.And support provides reference value for low-carbon construction of urban road maintenance projects.