Discarded or landfilled construction debris (specifically from roadway projects) may have untapped recycling potential to help stabilize different types of soil. However, blending some types of debris may not produce the desired results in all soils. Concrete diamond-grinding on pavement projects generates a non-hazardous waste byproduct called concrete grinding residue (CGR). CGR has known cementitious characteristics that suggest a latent use as a soil-stabilizing amendment, especially for poor and problematic soils. In Phase 1 of this study, Western Iowa loess soil was amended with CGR and subjected to rainfall simulations were performed on CGR-amended soils to measure the erodibility of several soil mixtures. In Phase 2, lab-based wind erosion simulations were performed on CGR-amended soils to evaluate wind erosivity due to “wind whip” from passing vehicles. Phase 1 of this study reviewed different methods for collecting CGR discharge; discussed design, construction, and use of a uniform compaction apparatus; and analyzed stormwater runoff from soil forms tested in an indoor rainfall simulator. Post-rainfall analysis included pH, water quality (turbidity) and total suspended-solids (TSS) tests. Lab tests on rainwater runoff samples from CGR-amended loess exhibited dramatically higher turbidity with an increase in TSS from 1.8 to 4.7 times that of untreated loess. In Phase 2, soil loss due to wind erosion was measured for CGR-amended loess and Class A-1 highway shoulder soils. Results showed that erosion was reduced in more granular shoulder material, decreasing -2.2 tons/mile (-25%) to -5.3 tons/mile (-58%), respectively. Conversely, for shoulder material containing more organics, soil erosion increased from 0.9 tons/mile (25%) to 1.9 tons/mile (50%) on average with the 20% and 40% CGR dosages, respectively.
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