LowEmissionAsphalt-136pg-WhitePaper-May2023

P a g e | 121 that peak photocatalytic optimization is achieved at as low as 2,000 parts per million 248 (0.2% of the wearing-course of the pavement). Since the process of imbedding a small, targeted amount of TiO 2 into pavements “piggybacks” already existing pavement maintenance and preservation techniques, the cost of the upgrade is only fractionally more expensive than routine maintenance. For new asphalt overlays, the added cost would be well under 10%. In terms of environmental burden shifting, there is no environmental hazard related to the aqueous suspension of titanium dioxide 249 then sequestered into a pavement subsurface. TiO 2 itself is inert and non-toxic. And the small amount of TiO 2 required per lane mile of a retrofit photocatalytic pavement has a feed-to-gate CO 2 e of just 0.003 tons. 250 Contrastingly, there is substantial environmental relief from deploying TiO 2 in roadway microenvironments: PlusTi TM Carbon Reduction Calculations In addition to PTI’s MRT life-cycle calculator which includes a 50% or more capex savings and a 500 to 1 carbon savings over overlays, 251 PTI has developed a carbon capture model for our photocatalytic pavement solutions, in part, through the help of: o Texas A&M University Center for Infrastructure Renewal o Michigan State University National Center for Pavement Preservation o Massachusetts Institute of Technology Concrete Sustainability Hub o DuPont ; Alcoa 252 o HeidelbergCement Group 248 Zollinger DG and Joshaghani A, Laboratory Investigation of the Effect of TiO 2 Topical Treatments on Concrete and Asphalt Samples , Texas A&M Transportation Institute, September 2018. 249 International Agency for Research on Cancer (IARC); California Office of Environmental Health Hazard Assessment (OEHHA), Safe Drinking Water and Toxic Enforcement Act of 1986 (Proposition 65). 250 Ruszakla MJA, et al, Low Carbon Footprint TiO 2 Substitutes in Paint, International Journal of Chemical Engineering and Applications , October 2015, University of Utah, Materials Science & Engineering Department. 251 Chehovits J and Galehouse L, Energy Usage and Greenhouse Gas Emissions of Pavement Preservation Processes for Asphalt Pavements, Transportation Research Board , 2010. 252 Chemours (formerly DuPont) Ti-Pure paint coatings; Alcoa Architectural Coatings – TiO 2 enhanced EcoClean Aluminum Panels.