• Bio-Based Renewable Additives for Anti-Icing Applications (Phase II)

      Nazari, Mehdi Honarvar; Oh, Taekil; Ewing, Alexander Charlemagne; Okon, Deborah Ave; Avalos, Brandon; Alnuaimi, Eisa; Havens, Eden Adele; Shi, Xianming (Center for Environmentally Sustainable Transportation in Cold Climates, 2019-01-24)
      The performance and impacts of several agro-based anti-icers along with a traditional chloride-based anti-icer (salt brine) were evaluated. A statistical design of experiments (central composite design) was employed for developing anti-icing liquids consisting of cost-competitive chemicals such as agro-based compounds (e.g., Concord grape extract and glycerin), sodium chloride, sodium metasilicate, and sodium formate. The following experimentally obtained parameters were examined as a function of the formulation design: ice-melting capacity at 25°F (−3.9°C), splitting strength of Portland cement mortar samples after 10 freeze-thaw/deicer cycles, corrosion rate of C1010 carbon steel after 24-hour immersion, and impact on asphalt binder stiffness and m-value. One viable formula (“best performer”) was tested for thermal properties by measuring its differential scanning calorimetry (DSC) thermograms, the friction coefficient of asphalt pavement treated by this anti-icing formulation (vs. 23 wt.% NaCl and beet juice blend) at 25°F after being applied at 30 gallons per lane mile (1 hour after simulated trafficking and plowing), and other properties (pH, oxygen demand in COD). Laboratory data shed light on the selection and formulation of innovative agro-based snow- and ice-control chemicals that can significantly reduce the costs of winter maintenance operations.
    • Recent Advances in Sustainable Winter Road Operations – A Book Proposal

      Shi, Xianming (Center for Environmentally Sustainable Transportation in Cold Climates, 2017-08)
      Investing in winter transportation operations is essential and beneficial to the public and the economy. The U.S. economy cannot afford the cost of shutting down highways, airports, etc., during winter weather. In the northern U.S. and other cold-climate areas, winter maintenance operations are essential to ensure the safety, mobility, and productivity of transportation systems. Agencies are continually challenged to provide a high level of service and improve safety and mobility in a fiscally and environmentally responsible manner. To this end, it is desirable to use the most recent advances in the application of materials, practices, equipment, and other technologies. Such best practices are expected to improve the effectiveness and efficiency of winter operations, to optimize material usage, and to reduce associated annual spending, corrosion, and environmental impacts. Currently, no professional societies, scientific journals, or textbooks are dedicated solely to sustainable winter road operations, and key information is scattered across a variety of disciplines. The objective of the proposed book is to summarize the best practices and recent advances in sustainable winter road operations for the purposes of education and workforce development. This book is now in press and can be cited as follows: Shi, X., Fu, L. (2017). Sustainable Winter Road Operations (Eds.). ISBN: 978-1-119-18506-2. Wiley-Blackwell.
    • Stress-corrosion cracking susceptibility of polystyrene/TiO₂ nanocomposite coated thin-sheet aluminum alloy 2024-T3 with 3.5% NaCl

      Baart, Brian V.; Chen, Cheng-fu; Ahn, Il Sang; Zhang, Lei (2020-05)
      This thesis reports an investigation into the performance of nanocomposite coatings, which consist of titanium dioxide nanoparticles within a polystyrene matrix, on the resistance to stress-corrosion cracking (SCC). The coatings are applied to compact tension specimens subject to conditions that promote failure by (SCC). It has been well documented in the literature that high-strength aluminum alloys such as 2024- T3 are prone to SCC when exposed to chloride media and sufficient levels of stress. The use of polymerbased nanocomposite coatings to protect aluminum alloy 2024-T3 has recently been shown to exhibit anticorrosion properties, which has been motivation for further study. The performance of such coatings on SCC is thus investigated here, using a fracture mechanics approach with compact tension specimens. The specimens are subject to a slow strain rate test using a constant displacement rate of 1.25 nm/s while exposed to periodically supplied 3.5% wt. sodium chloride solution. Measurements of load and crackmouth opening displacement data are recorded from the specimen throughout the test and used to characterize the response of the material to the applied mechanical loading in a corrosive environment. Results from the methods used herein showed a quantitative influence derived from the test results for several criteria of interest such as maximum load, time-to-failure, and fracture toughness. In total, four different coatings were applied; three with different titanium dioxide nanoparticle aspect ratios, and one without any titanium dioxide nanoparticles present in the polystyrene matrix. Characterization of the results showed that the shape of the titanium dioxide nanoparticle is a dominant factor that influences the susceptibility of aluminum alloy 2024-T3 to SCC.