Quantification and optimization of pavement design using Life Cycle Assessment

Abstract

The life cycle of road was divided into five different of life-cycle phases which are materials, construction, use, maintenance, and end of life. The construction of asphalt pavement has a significant impact on the environment, and energy use and greenhouse gas (GHG) emissions from asphalt pavement construction have been receiving increasing attention in recent years. At present, there is no universal criterion for the evaluation of GHG emissions in asphalt pavement construction. This paper proposes to define the system boundaries for GHG emissions from asphalt pavement by using a process-based life cycle assessment method. A method for evaluating GHG emissions from asphalt pavement construction is suggested. The potential energy embedded in the resource which is not utilized as energy source may be referred to as feedstock energy. Bitumen has a high energy content of 40.2 MJ/kg (Garg et al., 2006) but using bitumen as a fuel results in very high emissions (Faber, 2002; Herold, 2003) and high energy costs. Aggregate is considered to have no feedstock energy. It has also been reported in number of previous studies that bitumen has a low expended energy (energy used throughout the production of a material) of approximately 0.4 to 6 MJ/kg (Zapata et al., 2005). The results shows the total contribution analysis of the output in environmental impact. The highest value are from energy consumption which is 95% followed by Eutrophication 72 %, HH Criteria 70%, GWP 60%, Acidification 34% and Photochemical Smog 33% respectively.