air and water impacts of tx active concrete pavement st. louis, missouri, rte. 141

Air and Water Impacts of TX Active Concrete Pavement

St. Louis, Missouri, Rte. 141

TX Active Photocatalytic Cement• Developed by Italcementi • Contains titanium dioxide (a photocatalyst)

in anatase form• Abates smog-forming emissions (e.g.,

nitrogen oxides)• Self-cleaning, maintains surface color

NOX

siteNOXads

NO3-H+

●OH

Runoff water with a projected low NO3

- presence

Water

Adsorbs on ‘active’ site1

Oxidized by photo-generated hydroxyl ions

2

Washed from surface3

Photocatalytic Concrete

TX Active Research Project Overview• Relocated Rte 141 project, Chesterfield, MO

46,450 anticipated AADT Near St. Louis (population of 3,000,000))

• 1500 foot test section (placed in Oct 2011) Two-lift construction (2” on 7”) TX Active cement in top lift TX Active cement in pervious concrete shoulder

• Will monitor (over a 1-year period) Air quality (NOx, NO2, NO) Water quality (BOD, COD, nitrate)

• Funded by:

TX Active Project Site

TX Active

Control Air Sampling

Water Sampling

TX Active Project Photos