Laboratory and field evaluation of sustainable photocatalytic asphalt pavements

Document Type

Conference Proceeding

Publication Date



Titanium dioxide (TiO2) photocatalytic nanoparticles have the ability to trap and decompose organic and inorganic air pollutants, making it a promising technology as a pavement coating to mitigate the harmful effects of vehicle emissions. This technology may revolutionize construction and production practices of hot-mix asphalt by introducing a new-class of mixtures with superior environmental performance. The objective of this study was to assess the benefits of incorporating TiO2 in asphalt pavements. To achieve this objective, the photocatalytic effectiveness and durability of a water-based spray coating of TiO2 was evaluated in the laboratory. This study also presents the field performance of the country's first air-purifying photocatalytic asphalt pavement, located on the campus of LSU. Laboratory evaluation showed TiO2 was effective in removing NOx and SO2 pollutants from the air stream with an efficiency ranging from 31 to 55% for NOx pollutants and 4 to 20% for SO2 pollutants. The maximum NOx and SO2 removal efficiency was achieved at an application rate of 0.05 l/m2. Additionally, the efficiency of NOx reduction is affected by the flow rate of the pollutant, relative humidity, and UV light intensity. Preliminary field measurements show that the measured NO concentrations were significantly reduced right after the application of the TiO2 surface coating on the asphalt pavement. However, further field evaluation is required to determine the durability of the surface coating.

Publication Source (Journal or Book title)

Asphalt Paving Technology: Association of Asphalt Paving Technologists-Proceedings of the Technical Sessions

First Page


Last Page


This document is currently not available here.