• A Framework for Life Cycle Sustainability Assessment of Road Salt Used in Winter Maintenance Operations

      Cui, Na; Xie, Ning; Shi, Xianming (Center for Environmentally Sustainable Transportation in Cold Climates, 2016-12)
      It is important to assess from a holistic perspective the sustainability of road salt widely used in winter road maintenance (WRM) operations. The importance becomes increasingly apparent in light of competing priorities faced by roadway agencies, the need for collaborative decision-making, and growing concerns over the risks that road salt poses for motor vehicles, transportation infrastructure, and the natural environment. This project introduces the concept of Life Cycle Sustainability Assessment (LCSA), which combines Life Cycle Costing, Environmental Life Cycle Assessment, and Social Life Cycle Assessment. The combination captures the features of three pillars in sustainability: economic development, environmental preservation, and social progress. With this framework, it is possible to enable more informed and balanced decisions by considering the entire life cycle of road salt and accounting for the indirect impacts of applying road salt for snow and ice control. This project proposes a LCSA framework of road salt, which examines the three branches of LCSA, their relationships in the integrated framework, and the complexities and caveats in the LCSA. While this framework is a first step in the right direction, we envision that it will be improved and enriched by continued research and may serve as a template for the LCSA of other WRM products, technologies, and practices.
    • Freeze-Thaw Durability and Long-Term Performance Evaluation of Shotcrete in Cold Regions

      Qiao, Pizhong; Zhou, Zhidong (Center for Environmentally Sustainable Transportation in Cold Climates, 2017-12-31)
      This study’s aim was to evaluate the freeze-thaw durability of shotcrete in cold regions and predict its long-term performance. One benchmark mix design from the WSDOT was chosen to prepare samples for performance evaluation. Shotcrete specimens were conditioned in accordance with ASTM C666. The long-term freeze-thaw performance after certain cycles was evaluated using the dynamic modulus of elasticity test (ASTM C215), fracture energy test (RILEM 50-FMC), and X-ray CT microstructure imaging analysis. Probabilistic damage analysis was conducted to establish the relation between the durability life and the damage parameter for different probabilities of reliability using the three-parameter Weibull distribution model. The fracture energy test was found to be a more sensitive test method than the dynamic modulus of elasticity for screening material deterioration over time and for capturing accumulative material damage caused by rapid freeze-thaw action, because of smaller durability factors (degradation ratios) obtained from the fracture energy test. X-ray CT imaging analysis is capable of detecting microcracks that form and pore evolution in the aggregate and interface transition zone of conditioned samples. Moreover, the continuum damage mechanic-based model shows potential in predicting long-term material degradation and the service life of shotcrete.
    • Guidelines for the Use of Synthetic Fluid Dust Control Palliatives on Unpaved Roads

      Barnes, David; Connor, Billy (Center for Environmentally Sustainable Transportation in Cold Climates, 2017-07-06)
      The amount of small soil particles, dust, lost from typical unpaved roads to fugitive dust is staggering. A 1 km stretch of unpaved road can contribute over 2400 kg of dust to the atmosphere (4.2 ton/mile) in a typical 3-month summer season. Road managers typically manage dust from unpaved roads with various dust-control palliatives, which are effective for up to 1 year. Synthetic fluids are a relatively new category of dust-control palliatives. Unlike the more commonly used dust-control palliatives, such as salts, engineering guidelines do not exist for the application and maintenance of synthetic fluids on unpaved roads. To fill this void, we present through this document guidelines for road design and maintenance, palliative selection, application, and care of synthetic fluid-treated roadways.
    • Highly Abrasion-resistant and Long-lasting Concrete

      Liu, Jenny; Murph, Diane (2019-08)
      Studded tire usage in Alaska contributes to rutting damage on pavements resulting in high maintenance costs and safety issues. In this study binary, ternary, and quaternary highly-abrasion resistant concrete mix designs, using supplementary cementitious materials (SCMs), were developed. The fresh, mechanical and durability properties of these mix designs were then tested to determine an optimum highly-abrasion resistant concrete mix that could be placed in cold climates to reduce rutting damage. SCMs used included silica fume, ground granulated blast furnace slag, and type F fly ash. Tests conducted measured workability, air content, drying shrinkage, compressive strength, flexural strength, and chloride ion permeability. Resistance to freeze-thaw cycles, scaling due to deicers, and abrasion resistance were also measured. A survey and literature review on concrete pavement practices in Alaska and other cold climates was also conducted. A preliminary construction cost analysis comparing the concrete mix designs developed was also completed.
    • Impact of Cold Climates on Vehicle Emissions: The Cold Start Air Toxics Pulse

      Jobson, Tom; Huangfu, Yibo (Center for Environmentally Sustainable Transportation in Cold Climates, 2016-09)
      This project measured cold start emissions from four vehicles in winter using fast response instrumentation to accurately measure the time variation of the cold start emission pulse. Seventeen successful tests were conducted over a temperature range of -4°C to 10°C in winter 2015 at the Washington State University campus. Vehicle cold starts are thought to be a significant source of air toxic compounds in cold winter environments due to the rapid increase in mass emission rates with decreasing temperature. We used a proton transfer reaction mass spectrometer for high time resolution measurement of the emissions the air toxic compounds benzene, formaldehyde, acetaldehyde, in addition to toluene and C2-alkylbenzenes. Measured molar emission ratios relative to toluene in the cold start pulse were compared with cold start emission profiles for E10 fueled vehicles used in the EPA MOVES2014 model. We found that the measured acetaldehyde-to-toluene emission ratio was about a factor of 8 greater than the emission ratio used in MOVES2014. Measured formaldehyde-to-toluene emission ratios were a factor of 5 greater. Our study suggests that emission of the air toxics acetaldehyde and, likely, formaldehyde is significantly underestimated in wintertime by the MOVES2014 model.
    • The Impact of Snowfall on Airport Operations and Delays

      Lee, Jukwan; Yan, Jia (2019-03-31)
      Flight delays or cancelations due to snowfall are a costly inconvenience, not only to airports but also to airlines, passengers and society as a whole. However, no quantitative research has ever been done to provide an analytical explanation about the issue. Though being a reliable alternative to melt snow on the runway and mitigate flight delays, the Heated Pavement System is not adopted in any US airports because of concerns over the initial investments and maintenance costs being higher than the economic loss from delays during unpredictable snowfall days. Combining weather and domestic flight data in Boston and Los Angeles regions, we analyze the benefits and costs associated with installing the Heated Pavement System. Using two advanced econometric methods, the Difference in Difference in Difference (DDD) and the nearest neighbor matching, we first develop a Delay Analysis model to evaluate the exact effect of snowfall on flight delays, and then we calculate the delay costs. Based on the empirical findings, we conduct cost-benefit analysis of installing HPS at the three airports in Boston area. Our results indicate that HPS is feasible for airports with a great number of flights and passengers, such as Boston Logan airport.
    • Investigation of Alternative Deicers for Snow and Ice Control

      Fay, Laura; Akin, Michelle (Center for Environmentally Sustainable Transportation in Cold Climates, 2018-03-15)
      This technical report presents the findings of the laboratory analysis of potassium succinate (KSu) as a roadway deicer. Laboratory analysis included modified SHRP ice-melting testing, a differential scanning calorimetry (DSC) thermogram, and friction measurements to quantify performance. The overall results indicate that the performance of KSu is similar to that of NaCl at improving friction on roadways during snow and ice conditions. The results of DSC suggest that KSu can be applied as a roadway deicer at -5°C (23°F) and above. However, KSu does not function as a deicer at colder temperatures where salt brine will work (the generally agreed upon lowest working temperature for salt brine is 15°F [-9.5°C]). The results of the laboratory testing show that KSu functions as a roadway deicer with slightly lower ice-melting rates than salt brine. The ice-melting rates, DSC, and friction performance testing of KSu show that the product performs as a deicer at warmer temperatures than salt brine, with slightly less ice-melting capacity and similar friction performance. Based on these and previous results showing lack of corrosion in metals, equipment, and pavements from use of KSu and similar BOD of KSu to potassium acetates, KSu appears to be a viable option as a roadway deicer at temperatures at or above -5°C (23°F). Use of KSu as a roadway deicer may be focused in areas where there are concerns about impacts to infrastructure, equipment, or pavements, such as on bridges, elevated roadways, in parking garages, or on newer concrete pavements. Potential concerns with the use of KSu as a roadway deicer are its price, lack of full-scale manufacturing of KSu at this time, and the BOD exerted by the product. Additional testing to fully quantify the environmental impacts of KSu on soil, water, flora, and fauna is recommended. If water quality and BOD are of concern, application of this product is not recommended in large quantities and during times of low water flow.
    • Laboratory and Field Evaluation of Modified Asphalt Binders and Mixes for Alaskan Pavements

      Liu, Jenny; Liu, Jun (2019-08)
      In order to properly characterize modified asphalt binders and mixes for Alaskan pavements, this study evaluated properties of 13 asphalt binders typically used in Alaska from three different suppliers, and 10 hot mix asphalt (HMA) mixtures which were either produced in the lab or collected from existing paving projects in Alaska. Various binder and mixture engineering properties were determined, including true high binder grades, complex modulus (G*), and phase angle (δ) at high performance temperatures, multiple stress creep recovery rate and compliance, bending beam rheometer stiffness and m-value, Glover-Rowe parameter, ΔT, rheological index, and crossover frequency for binders, and rut depth, critical strain energy release rate (Jc), Indirect tensile (IDT) creep stiffness and strength for mixtures. Binder cracking temperatures were determined using asphalt binder cracking device. Mixture cracking temperatures were determined with IDT creep compliance and strength data. It was found that rutting and cracking resistances of the mixtures with highly modified binders were better than the mixture with unmodified asphalt binder (PG 52-28). Future recommendations for highly modified asphalt binders applications and research were provided based on laboratory testing results and field survey evaluation.
    • Long-term Stabilization of Disturbed Slopes Resulting from Construction Operations

      Perkins, Robert (Center for Environmentally Sustainable Transportation in Cold Climates, 2018-03)
      Highway construction disturbs soil, which must be stabilized to prevent migration of soil particles into water bodies. Stabilization is enforced by law, regulation, and a permit system. Stabilization is most efficiently attained by reestablishment of vegetation, and permits sometimes specify this method of stabilization. Revegetation is difficult in northern Alaska, and seeded grasses often die in a year or two, while reestablishment with native vegetation takes several years. A literature search and interviews with experts indicates that simply extending this “establishment period” has many practical difficulties. Field investigations and interviews indicate that in northern Alaska little erosion occurs at slopes with failed vegetation, which implies that vegetation was not critical to reducing contamination and the expense of revegetation was unnecessary. However, when revegetation is specified in standard permit language, and contractor, owner, and regulator must close out projects, grasses are utilized. This research supports the recommendation that the Alaska Department of Transportation and Public Facilities work with the Alaska Department of Natural Resources and the Alaska Department of Environmental Conservation to develop special standards for projects north of the Brooks Range and between the Brooks and Alaska ranges, that recognize the low erosion potential of clean road fill – embankments.
    • Mapping the Wolverine Way: Identifying Conservation Corridors and Transboundary Linkages in the Canadian Crown of the Continent Region

      Clevenger, Anthony P. (2019-09-13)
      The Canadian Crown of the Continent (CCoC) is one of three zones where wolverines can move between Canada and the US, providing the last links for recruitment and ultimately gene flow to the highly fragmented population in the US Rocky Mountains. However, a combination of rapidly expanding logging, energy development and motorized recreation, along with a growing road network, threatens to fragment and diminish connections in this critical transboundary linkage between the US and Canada. This report summarizes a project to complete a 3-year sampling effort in the CCoC, which in turn completed a larger 6-year effort over a vast area of the central and southern Canadian Rockies. In 2016, the research team surveyed the last unsampled portion of the Alberta Rockies (south of Kananaskis Country to Highway 3) in addition to a substantial portion of the East Kootenay region of the British Columbia Rockies (BC; >9000 km2). This follow-up effort allowed the team to complete an entire ecoregion-wide wolverine survey in the Canadian Rockies ecoregion, from the US-Canadian border north to Banff and Yoho National Parks. From this data, researchers created density estimates and occupancy models of wolverine distribution and its multiple landscape stressors across an extensive and complex region of the Great Northern Landscape. The report summarizes research findings and makes recommendations regarding management strategies.
    • Modeling Impacts of Cold Climates on Vehicle Emissions

      Chung, Serena (Center for Environmentally Sustainable Transportation in Cold Climates, 2017-01-20)
      This project relates to the research thrust area of ‘environmental impact assessment,' specifically the impact of cold climates on vehicle exhaust emissions. Motor vehicles emit pollutants that are harmful to human. Emissions are thought to be elevated during engine cold starts. During winter, low-lying temperature inversion can trap vehicle emissions near the surface, leading to significantly elevated pollutant concentrations. Despite the importance, vehicle emissions data for cold climates are sparse and the accuracy of vehicle emissions model parameterizations for cold climates is not known. The goal of this project is to improve ability of EPA's Motor Vehicle Emission Simulator (MOVES) model to simulate cold start emissions in cold climates
    • Monitoring Winter Flow Conditions on the Ivishak River, Alaska

      Toniolo, Horacio; Vas, D.; Keech, J.; Bailey, J. (Center for Environmentally Sustainable Transportation in Cold Climates, 2017-09)
      The Sagavanirktok River, a braided river on the Alaska North Slope, flows adjacent to the trans-Alaska pipeline for approximately 100 miles south of Prudhoe Bay. During an unprecedented flooding event in mid-May 2015, the pipeline was exposed in an area located approximately 20 miles south of Prudhoe Bay. The Ivishak River is a main tributary of the Sagavanirktok River, but little is known about its water flow characteristics and contribution to the Sagavanirktok River, especially in winter and during spring breakup. To gather this information, we installed water level sensors on two main tributaries of the Ivishak River (Upper Ivishak and Saviukviayak rivers), early in winter season 2016–2017, in open-water channels that showed promise as locations for long-term gauging stations. Our ultimate goal was to find a location for permanent deployment of water level sensors. By February, the first sites chosen were ice covered, so two additional sensors, one on each river, were deployed in different locations. Some of the sensors were lost (i.e., carried away by the current or buried under a thick layer of sediments). Water level data gathered from the sensors showed a maximum change of 1.07 m. Winter discharge measurements indicate a 44% reduction between February and April 2017. A summer discharge measurement shows a 430% increase from winter to summer.
    • Near-Roadway Air Pollution: Evaluation of Fine Particulate Matter (PM2.5) and Ultrafine Particulate Matter (PM0.1) in Interior Alaska

      Aggarwal, Srijan; Kadir, Abdul; Belz, Nathan (2019-01-28)
      This report presents a study of fine (PM2.5) and ultrafine (PM0.1) particles in the Fairbanks North Star Borough (FNSB) in Interior Alaska, with specific emphasis on the relationship of ultrafine particles (UFPs) to vehicular traffic. Chapter 1 provides a summary of published literature on particulates in air from vehicular emissions. Chapter 2 provides a novel and robust GIS-based data analysis approach to PM2.5 data collected by the FNSB. This analysis approach is convenient for identifying hotspots, as well as locations where PM2.5 changes either abruptly or continuously or does not change at all. The results reveal that average on-roadway PM2.5 concentrations are higher in North Pole than in Fairbanks, and mean levels are higher in stationary background monitoring data than in mobile monitoring on-roadway data. Not surprisingly, significant negative correlations were found between temperature and PM2.5. Chapter 3 presents the results from the data collection campaign to measure UFPs at roadside locations in Fairbanks and North Pole and investigate the relationship of UFPs with traffic and meteorological parameters. Multilinear predictive models were developed for estimation of UFPs and PM2.5 based on weather and traffic parameters. Overall, this study improves our understanding of on- and near-roadway particulates in a cold-climate region.
    • A New Sustainable Additive for Anti-Icing Pavement

      Zhang, Yan; Shi, Xianming (2019-08-30)
      Based on a review and synthesis of the state-of-the-art literature on asphalt pavement with anti-icing additives, this laboratory study developed an anti-icing asphalt pavement that incorporates innovative salt-storage additives with a sustained salt-release rate. These additives were prepared through a surface treatment approach, in which zeolite containing CaCl2 was coated by a porous epoxy layer. The anti-icing performances and mechanical properties of asphalt mixture with the obtained additives were investigated. The experimental results indicated that the anti-icing capability of asphalt mixture at both -3.9 °C (25°F) and -9.4 °C (15°F) was significantly improved by the addition of the additives, and the friction coefficient of the pavement at 60 min after moisture spray was 0.75 at -3.9 °C to 0.55 at -9.4 °C. Reducing the size of additives resulted in a further improved anti-icing capability. Under simulated conditions, the estimated effective anti-icing period of asphalt pavement with additives #8, #16, and #30 were 5.8 years, 9.9 years and 15.3 years, respectively. The incorporation of the additives exhibited negligible effect on the moisture damage resistance of asphalt mixture, and almost all the mixtures passed the WSDOT specification as well as the Wisconsin and Iowa specifications. The rutting resistance, mid-temperature (fatigue) cracking resistance, and low-temperature (thermal) cracking resistance of asphalt mixture improved due to the addition of these anti-icing additives to various extents.
    • A Novel Systematic Strategy Towards Air-Purifying, Corrosion Resistant and Self-Healing Concrete Infrastructure

      Yang, Zhengxian (2019-09-15)
      Transportation causes major emissions of harmful gases (NOx, CO, VOCs). These pollutants also travel long distances to produce secondary pollution such as acid rain. The most popularly used photocatalytic cementitious composites based on TiO2 achieve the air purification function under ultraviolet sunlight, significantly impeding a broader application of photocatalytic cementitious composites. This study focused on developing an environmentally friendly and durable cementitious system based on the multifunctional photocatalytic Graphitic carbon nitride (g-C3N4). The photocatalytic cementitious composites (PCC) were prepared in three manners: (1) incorporating g-C3N4 nanosheets (CNNs) in cement at three mixing dosages (0.5%, 1% and 2% by weight of cement), (2) applying CNNs at various concentration levels as the coating on recycled asphalt pavement aggregate, (3) applying CCNs s with vinyl chloride/vinyl ester/ethylene copolymer (as a binder) as the coating on cement mortar. The photocatalytic performance and durability of the newly developed cementitious composites were evaluated systematically and the results showed that the PCC hold marked efficiency in terms of NOx removal and self-cleaning when the CNNs were applied in a proper way. The obtained knowledge sheds light on a future perspective of developing a novel systematic strategy towards air-purifying, corrosion resistant, and self-healing concrete infrastructure.
    • Numerical Simulation of Snow Deposition Around living Snow Fences

      Petrie, John; Zhang, Kun; Shehata, Mahmoud (2019-09-13)
      In this study, computational fluid dynamics (CFD) was used to investigate the air flow around porous snow fences to gain insight into snow transport and deposition in the vicinity of fences. Numerical simulations were performed to validate the CFD approach using experimental data from a wind tunnel study. Subsequent simulations were used to test the use of a porosity model to represent fence geometry and determine the effect of fence spacing for fences comprised of multiple rows. The results demonstrate that CFD simulations can reproduce the aerodynamics around porous fences. Additionally, the flow field generated with a porosity model is in close agreement with that from a model with explicit representation of fence porosity. Simulations of fences comprised of two rows spaced at various distances demonstrate that when the row spacing is small the fence behaves as a single row.
    • Performance of TenCate Paving Interlayers in Asphalt Concrete Pavements

      Liu, Jenny; Zhao, Sheng; Li, Lin (Center for Environmentally Sustainable Transportation in Cold Climates, 2017-08)
      As a continued effort of a previously completed project entitled “Performance of TenCate Mirafi PGM-G4 Interlayer-Reinforced Asphalt Pavements in Alaska,” this project evaluated two newly modified paving interlayers (TruPave and Mirapave) through overlay, dynamic modulus tests and low-temperature performance tests. A field survey was conducted to further evaluate the performance of three paving interlayers (G4, G50/50, and G100/100) applied to field sections constructed in May 2013 at Milepost 148–156 Richardson Highway in Alaska. Overlay test results indicate that asphalt concrete (AC) with paving interlayers (TruPave and Mirapave) shows lower reduction in peak load, suggesting better cracking resistance. The dynamic modulus measurement of AC with paving interlayers reveals more rational results from the IDT mode test than the AMPT method due to similar stress conditions in the paving interlayer. With paving interlayers, the temperature sensitivity and cracking potential of AC material were reduced according to the results from the IDT creep test. Field survey results confirm that all sections reinforced with paving interlayers (G4, G50/50, and G100/100) had better cracking resistance than the control section.
    • Pre-Stress Loss Due to Creep in Precast Concrete Decked Bulb-Tee Girders Under Cold Climate Conditions

      Vandermeer, Drew; Ahn, Il-Sang (2019-07-31)
      Accurate estimation of pre-stress losses is one of the important issues for the design of precast, pre-stressed concrete bridge girders. While this subject has been long studied by many researchers, studies on pre-stress losses in cold climates are minimal. In the present research, long-term pre-stress loss due to concrete creep was studied based on concrete creep test. Two concrete creep test frames were fabricated and placed indoors and outdoors. Concrete strains were measured by Demountable Mechanical Strain Gauge (DEMEC) from two 612 high-strength concrete cylinders in each frame. The concrete strains were collected for 11 months (7/26/2017 – 6/21/2018) after loading, and outdoor ambient temperature dropped below 0C between 100 and 250 days. Between 50 and 100 days, two curves from the two frames are similar in their patterns and values. After 100 days, the total strain from the indoor frame slowly increased reaching 1,600 and 1,700 after 250 days. However, the total strain from the outdoor frame varied between 1,000 and 1,500 and the averaged total strain was 1,300 after 250 days. In cold temperature, the occurrence of concrete creep and shrinkage was suppressed.
    • Prediction of Thermal Behavior of Pervious Concrete Pavements in Winter

      Chen, Zhao; Nantasai, Benjamin; Nassiri, Somayeh; Haselbach, Liv (Center for Environmentally Sustainable Transportation in Cold Climates, 2017-05-15)
      Because application of pervious concrete pavement (PCPs) has extended to cold-climate regions of the United States, the safety and mobility of PCP installations during the winter season need to be maintained. Timely application of salt, anti-icing, and deicing agents for ice/snow control is most effective in providing sufficient surface friction when done at a suitable pavement surface temperature. The aim of this project was to determine the thermal properties of PCP during the winter season, and to develop a theoretical model to predict PCP surface temperature. The project included a laboratory and a field component. In the laboratory, thermal conductivity of pervious concrete was determined. A linear relationship was established between thermal conductivity and porosity for pervious concrete specimens. In the field, the pavement temperature in a PCP sidewalk installation at Washington State University was monitored via in-pavement instrumentation. Based on the field data, the Enhanced Integrated Climatic Model (EICM) was developed and validated for the site, using PCP thermal properties and local climatic data. The EICM-predicted PCP surface temperature during the winter season agreed well with the field temperature. Overall, the predicted number of days that the pavement surface fell below 32°F agreed well with the number based on field data for 85% of the days. Therefore, the developed model is useful in identifying those days to apply deicer agents. Finally, a regression model using climatic indices was developed for PCP surface temperature prediction in the absence of a more advanced temperature model.
    • 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.