Iowa State University
Backslopes; Diamond grinding; Environmental impacts; Foreslopes; Roadside flora; Vegetation control
Diamond grinding of Portland Cement Concrete (PCC) highway surfaces, a maintenance operation carried out to extend the pavement service life, generates a high-pH and high alkalinity slurry (water, concrete and aggregate residue), referred to as Concrete Grinding Residue (CGR). The objective of the proposed research is to gain a stronger understanding of the CGR effects on soil, water infiltration, and vegetation through an in-situ, statistically rigorous study that will analyze inslope and/or backslope soil samples and assess soil and vegetation properties before and after placement of the CGR. Based on the study findings, Minnesota Department of Transportation's (MnDOT's) Office of Environmental Stewardship will: l) be able to better assess the need for soil amendments, either prior to or after CGR placement; 2) be in a better position to recommend possible changes to CGR slurry offloading or placement practices; and 3) be able to better assess the need for possible changes to inslope/backslope seed mixes.