Comparative Life Cycle Assessment between Warm SMA and Conventional SMA

Details

• Alternative Title:
  CIVIL ENGINEERING STUDIES : Illinois Center for Transportation Series No. 11-090
• Creators:
  Leng, Zhen ; Al-Qadi, Imad
• Corporate Creators:
  Illinois Center for Transportation
• Corporate Contributors:
  Illinois Tollway ; United States. Federal Highway Administration
• Subject/TRT Terms:
  • Paving materials
  • Warm mix paving mixtures
  • Asphalt
  • Life cycle analysis
  • Life cycle costing
  • Warm-mix asphalt
  • Life cycle assessment
  • Life cycle cost analysis
• Publication/ Report Number:
  ICT-11-090 ; UILU-ENG-2011-2016
• Resource Type:
  Tech Report
• Geographical Coverage:
  Illinois
• Corporate Publisher:
  Illinois Center for Transportation
• Abstract:
  This report presents the comparative life cycle assessment (LCA) between warm stone mastic asphalt (SMA) and conventional ; SMA. Specifically, the study evaluated and compared the life cycle environmental and economic performances of two mixtures: a warm ; SMA binder course mixture with a chemical additive and a control hot SMA binder course mixture. Both of these mixtures were utilized ; as part of a complete overlay project on the Veterans Memorial Expressway (I-355) near Chicago as part of the Illinois Tollway system. ; The results of this study indicate that the warm SMA provides significant environmental benefits compared to the control hot SMA. ; When the mixing temperature was decreased from 325 to 280 oF (168 to 138 oC), the overall environmental impact of the material, ; production, transportation, and placement was reduced by 6.4% due to the use of warm mix additive. More environmental benefits can ; be expected if the mixing temperature is further lowered. It was also concluded that using warm mix additive slightly increases the initial ; construction cost of SMA pavement. However, the warm SMA overlay allows for traffic to be opened earlier, so the user cost caused by ; traffic delay is reduced, and the total economic cost of the warm SMA is lower than that of the control SMA. In addition, the warm SMA ; allows for the use of a higher percentage of RAP because of less binder aging. With a 10% increase in RAP usage, the initial ; construction cost of the warm SMA becomes 3.5% lower than that of the control SMA. The overall performances of the control SMA and ; the warm SMA were compared by calculating a weighted environmental and economic score and the total cost (environmental, agency, ; and user costs). Both the weighted score and total cost data show that the warm SMA provides better overall performance compared to ; the control SMA. Therefore, besides being more environmentally friendly, the warm SMA is also economically competitive compared to ; the control SMA. ; This study didn’t include the cost benefits of the warm SMA due to an extended paving season and longer hauling distance because ; these benefits are difficult to quantify. In addition, the warm SMA may reduce the risk of poor compaction during construction, which ; ensures long-term pavement performance, and therefore saves costs related to maintenance and rehabilitation.
  More +
• Format:
  PDF
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/24789/dot_24789_DS1.pdf
• File Type:
  [PDF - 1.39 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:bb7c5d37417a0cfd5c38fb2b1e1d39cbb9b514e082b1032a147120535f575568