Construction projects that involve flexible pavements and wind turbines typically utilize and handle large volumes of materials. Polymer modifications can improve the durability of flexible pavements and reduce the amount of virgin materials used over the service life. Crumb rubber (CR) from end-of-life tires might substitute the synthetic polymer in the asphalt mixtures, which would reduce the use of virgin materials and the number of tires deposited in landfills. Wind power contribution to global electricity generation is expected to increase from 5 to 30% by 2050. This growing capacity will lead to increasing construction of wind farms globally. The scope of the study presented in this dissertation includes evaluating the mechanical, environmental, and toxic impact of different asphalt mixtures containing CR and the material demand for wind turbines in the USA and globally until 2050.Polymer coated rubber (PCR) and devulcanized rubber (DVR) are enhanced CR products used as recycled modifiers in asphalt mixtures. However, a comprehensive evaluation of the mechanical, environmental, and toxic impact of asphalt mixtures containing enhanced CR is still missing and necessary to evaluate whether the replacement of synthetic polymers with recycled modifiers is viable. In this study, life cycle assessment (LCA) and mechanistic-empirical pavement design (MEPDG) were used to compare the environmental impact of enhanced CR (PCR, dry and wet technology, and DVR) used in pavement materials with reference mixes (Control, unmodified, and SBS, modified with the synthetic polymer styrene-butadiene-styrene). Moreover, the potential leaching of metals from the same mixtures was assessed through the mass transfer rate of constituents, the 1315 EPA method. PCR dry mixture performed mechanically and environmentally as well as the SBS mix. Over the service life of road pavement, it was observed that the use of PCR dry and SBS mixtures leads to material savings up to 2.4 times compared to the control mixture. Leaching tests revealed that zinc was present in all asphalt mixtures, with a concentration greater than the drinking water standard limit. The number of wind turbines that are expected to be built by 2050 to meet the renewable energy targets will require a large amount of material mining and transformation. The material demand for wind turbines installed in the USA and the rest of the world were estimated and compared to the expected production until 2050. In addition, the carbon footprint and the cumulative energy demand associated with the material production were quantified based on the annual addition capacity using three different outlooks for the USA and one for the rest of the world. The material demand in the USA and globally was lower than the expected material production. The carbon footprint for material manufacturing for all wind turbines built in 2050 will be eight times lower than the CO2 equivalent emitted by coal power plants in the USA in that year. Lowering the environmental impact of wind turbine manufacturing will increase the competitiveness of wind energy compared to non-renewable sources.
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