Impact on Emissions and Energy Consumption of Evolving Pavement Materials Practices from 1990 to 2010: A Washington State Department of Transportation Case Study

摘要

GHG emissions and energy consumption are growing national and international concerns leading to an increase in attention to LCA in multiple areas. There significant effort in the pavement industry to develop LCA, use it as a decision-support tool, and to quantify the environmental benefits of common pavement practices. Here, Roadprint, an online LCA tool (http://clients.paviasystems.com/wfl), is used to quantify the greenhouse gas (GHG) emissions and energy consumption changes for four basic pavement materials practices at the Washington State Department of Transportation (WSDOT) between 1990 and 2010: (1) use of warm mix asphalt (WMA) in place of conventional hot mix asphalt (HMA), (2) incorporation of reclaimed asphalt pavement (RAP) in HMA pavement mixtures, and (3) use of fly ash and (4) slag as portland cement substitutes in portland cement concrete (PCC) pavements. Results show that 2010 realized savings over 1990 baseline values range from 4-22% for GHG emissions, and 5-18% for energy consumption depending upon practice. Ultimate savings based on current technology are potentially higher in the 17-44% range for GHG emissions and 12-32% range for energy consumption. These savings constitute about 0.01-0.1% of the total WSDOT emissions and energy consumption if the WSDOT fleet and vehicles driving on WSDOT pavements are considered. Nonetheless, these savings are real and permanent and understanding their magnitude can help in decision-making.