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Technology Demonstrations Project: Environmental Impact Benefits with "TX Active" Concrete Pavement in Missouri DOT Two-Lift Highway Construction Demonstration


Principal investigators:

Co-principal investigators:

Project status


Start date: 09/04/09
End date: 07/25/12


Report: Technology Demonstrations Project: Environmental Impact Benefits with (4.77 mb pdf) October 2012


Sponsor(s): Federal Highway Administration

About the research


This research effort evaluated the environmental impacts and benefits obtained from concrete paving materials blended with photo-chemically-active titanium dioxide (TiO2). The project was completed in combination with a full-scale Missouri Department of Transportation (MoDOT) two-lift paving demonstration project in the St. Louis, Missouri urban area. Two innovative photo-catalytic concrete paving materials have been studied during this project, including: a) a photocatalytic concrete mainline pavement and b) a photocatalytic pervious concrete shoulder pavement. The mainline pavement material was applied using a two-lift paving strategy, where the lower, base-level layer was constructed with less expensive materials (e.g., a low cementitious-content base lift), and the thinner top wearing course was then overlaid immediately with concrete containing photocatalytically active cement. The included photocatalytic concrete paving material is marketed under the trade-name TX Active. The second shoulder pavement element involved a similar, photocatalytic concrete material also containing the titanium dioxide additive, although in this instance the TiO2 was blended into a pervious (rather than conventional) concrete for the roadside shoulder pavement material. Together, this set of innovative mainline and shoulder paving materials, including both a two-lift photocatalytic mainline pavement and a photocatalytic pervious shoulder pavement, is believed to represent one of the most technically advanced and environmentally-friendly concrete pavement systems ever employed in the US. Field-scale assessment of this innovative highway involved both passive and active air quality NO and NO2 testing, respectively using integrative Ogawa samplers and a 2B Technologies ozone titration analyzer. This field-scale assessment also involves water-quality testing of mainline and shoulder pavement runoff.