The Missouri Department of Transportation, in collaboration with the Federal Highway Administration, the National Concrete Pavement Technology Center at Iowa State University's Institute for Transportation, the Essroc Italcementi Group, and Lehigh Hanson, announces the start of extensive research on the environmental benefits of using concrete made with an innovative new cement product in the construction of highways. The cement used in the concrete is blended with photo-chemically-active titanium dioxide (TiO2). Marketed under the trade name "TX Active," TiO2 is capable of reducing the environmental pollutants from vehicle exhausts.

The proposed research is intended to determine the benefits obtained from concrete paving materials made with cement blended with TX Active and to assess the overall impact of using this special concrete in highway construction projects. This research will occur in combination with an upcoming Missouri Department of Transportation (MoDOT) two-lift paving demonstration project on Highway 141 in the St. Louis, Missouri urban area, currently scheduled for the fall of 2011. Two innovative applications will be studied:

1) A photocatalytic concrete mainline pavement
2) A photocatalytic pervious concrete shoulder pavement

The mainline pavement material will be applied using a two-lift paving strategy, which involves the placement of two wet-on-wet layers of concrete instead of a single, homogeneous layer. The lower, base-level layer is expected to be constructed with less expensive materials (e.g., a low cementitious-material content base lift) which will then be overlaid with a thinner top wearing-course of concrete containing cement blended with TX Active.

The shoulder pavement element of this research effort involves cement blended with TX Active. In this instance the cement blended with TX Active will be used in a pervious (rather than conventional) concrete application. Together, this set of innovative mainline and shoulder paving materials, including both a two-lift photocatalytic mainline pavement and a photocatalytic pervious shoulder pavement, are believed to represent one of the most technically advanced and environmentally-friendly concrete pavement systems ever employed.

Following the paving, monitoring of the air and water impacts will begin and are scheduled to be conducted for one full year. The research monitoring is being accomplished by researchers at Iowa State University and the University of Missouri at Kansas City who specialize in this area of environmental science. The lead researchers are Dr. James Alleman from Iowa State University and Dr. John Kevern from UMKC.

The project is being constructed by Fred Weber from St. Louis Missouri.