Browsing by Subject "Recycled materials"

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    Evaluation of engineering properties of drill cuttings for construction materials
    (2023-08-25) Mena Arango, Karen E.; Gilbert, Robert B. (Robert Bruce), 1965-; El Mohtar, Chadi Said
    This research arises my motivation as an opportunity to evaluate one of the applications for drill cuttings in the construction industry and thus contribute to the reduction of the environmental hazard that may affect human health and the environment. The main objectives of this study are 1) Investigate the potential use of drill cuttings disposed on a specific site as embankment fill materials; 2) Provide input for drill cuttings characterization regarding engineering and environmental properties; 3) Perform leachability tests on drill cuttings to determine their potential of leaching Total Organic Content as the water circulates through a soil column; 4) Evaluate the impact that lime and organoclay may have on the engineering and environmental properties of drill cuttings. The methodology of this research included site visits, sampling, and laboratory tests for the material characterization, such as particle size distribution, Atterberg limits, moisture content, compaction, unconfined compressive strength, pH, Oxidation Reduction Potential, and Total Organic Content. From working on this research, it was possible to conclude that 1) The results of material characterization for the sampled drill cuttings indicate an average natural moisture content of 21%, neutral pH, the material classification corresponds to Clayey Sand (SC), with an average Liquid Limit of 35% and an average Plasticity Index of 17%; 2) The results for engineering properties for the sampled drill cuttings indicate an optimum water content of 19% and maximum dry density of 100 pcf when compacted with comparable energy for embankment fills, TxDOT 114 or Standard Proctor compaction. The unconfined compression strength when the material is compacted to its maximum dry density with Standard Proctor compaction averages 22 psi; 3) The Oxidation Reduction Potential (ORP) of the sampled drill cuttings, as per the leaching test (EPA 1314 Method), reached an average of 218 mV at a cumulative liquid-to-solid ratio (L/S) of 10; 4) The cumulative Total Organic Content (TOC) at the end of the leaching tests (EPA 1314 Method) for the sampled drill cuttings indicates an average of 0.35 mg/g of solids for drill cuttings and an average of 0.21 mg/g of solids for the mixes with 5% of organoclay; 5) The addition of lime to the sampled drill cuttings does not show any significant benefit that could promote its use with these materials. The addition of organoclay tends to increase the Oxidation Reduction Potential (ORP) and reduce the Total Organic Content. According to the solubility control line on the cumulative release curve, the sampled drill cuttings mixed with 5% organoclay by weight show a low potential to leach into the environment under landfill conditions. These results indicate good potential to amend the sampled drill cuttings with organoclay in order to improve their suitability for use as embankment fill material if leaching is a concern. Further research is recommended to 1) Determine the type and optimum stabilizer content to meet the plasticity index and compressive strength requirements for roadway construction; 2) Investigate the effect of organoclay and other binders over time after mixing with drill cuttings.