Laboratory and Field Evaluation of Sustainable Photocatalytic Asphalt Pavements

With the ability to trap and decompose organic and inorganic air pollutants, titanium dioxide (TiO2) is a promising technology to mitigate the harmful effects of vehicle emissions as a pavement coating. By introducing a new class of mixtures with superior environmental performance, this technology may revolutionize construction and production practices of hot-mix asphalt. Assessing the benefits of incorporating TiO2 in asphalt pavements was the objective of this study. The photocatalytic effectiveness and durability of a water-based spray coating of TiO2 was evaluated in the laboratory, in order to achieve this objective. Also presented in this study is the field performance of the country's first air-purifying photocatalytic asphalt pavement, located on the campus of Louisiana State University (LSU). It was shown by laboratory evaluation that TiO2 was effective in removing nitrogen oxide (NOx) and sulfur dioxide (SO2) pollutants from the air stream with an efficiency ranging from 31 to 55% for NOx pollutants and 4 to 20% for SO2 pollutants. Removal efficiency was achieved at a maximum for NOx and SO2 removal at an application rate of 0.05 l/m². The efficiency of NOx reduction is additionally affected by the flow rate of the ultraviolet (UV) light intensity, pollutant, and relative humidity. It is shown by preliminary field measurements that the measured NO concentrations were significantly reduced right after the application of the TiO2 surface coating on the asphalt pavement. However, in order to determine the durability of the surface coating, further field evaluation is required.

Language

  • English

Media Info

  • Media Type: Print
  • Features: Figures; Photos; References; Tables;
  • Pagination: pp 1-23
  • Monograph Title: Asphalt Paving Technology 2012
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 01523064
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Apr 9 2014 1:17PM