• SIZING HYDRAULIC STRUCTURES IN COLD REGIONS TO BALANCE FISH PASSAGE, STREAM FUNCTION, AND OPERATION AND MAINTENANCE COST

      Blank, Matt; Dockery, David; Pohl, Christina (2019-03)
      The purpose of this research was to evaluate how characteristics of hydraulic structures, such as slope or size, used at crossings over waterways relate to operation and maintenance (O&M) effort, fish passage, and stream function. Data on O&M concerns, fish passage concerns, and crossing characteristics were collected from 45 road-stream crossings in Prudhoe Bay, Alaska, during lower and higher water periods in both 2014 and 2015 (four events total). Logistic regression and generalized mixed models were used to examine relationships between O&M effort (response) and five explanatory variables. For all data from all years combined, there were no observable associations among O&M and culvert type or constriction ratio. However, lower constriction ratios were observed for sites with O&M needs in the June 2014 data set. The proportion of sites with both fish passage and O&M concerns was 0.52; comparatively, the proportion of sites with no fish passage concern but with O&M concern was 0.35.
    • Stormwater-Pavement Interface in Cold Climates

      Haselbach, Liv; Nassiri, Somayeh (Center for Environmentally Sustainable Transportation in Cold Climates, 2017-05-27)
      This project relates to “managing stormwater runoff in cold climates” and addresses the feasibility of low-impact development at a regional demonstration site in eastern Washington. The studies relate to seven large permeable pavement systems. The findings for similar climates and soils are as follows:  The draindown times for retention in Palouse or similar clay soils may handle many typical storms.  On average, every square foot of a permeable pavement system installed also receives run-on from another square foot of impermeable pavement, doubling its impact on both stormwater quantity reduction and stormwater quality improvement.  Most of the clogged sections on various applications were downslope of other areas.  Permeable pavements installed in areas targeted for additional stormwater quantity control and quality improvement may be feasible.  On average, the cleaning for installations is less frequent than annually. Power washing plus vacuuming appears to be an effective method for pervious concrete.  Surface distress was usually where vehicles turned, or from placement activities.  Preliminary studies on various surface treatments on pervious concrete show promise for added safety benefits under wintry conditions.  Both detention-type and retention-type permeable pavement systems appear to have little negative impact on neighboring soils in the winter under the study conditions. However, further research is needed for different designs of retention-type systems to ensure that water volumes in the aggregate storage bed do not allow for sufficient water flow into neighboring soils that might result in ice lens formation or other negative impacts.
    • Sustainable Construction in Remote Cold Regions

      Perkins, Robert (Center for Environmentally Sustainable Transportation in Cold Climates, 2015-12-31)
      The goal of this project was to identify sustainable construction techniques appropriate for remote and cold regions, some of which apply to operations and maintenance as well. The vast body of literature regarding green construction in warm regions was reviewed, and information that might be applicable to cold and remote regions was ascertained. A hierarchal taxonomy was developed to categorize the information and reduce it to a form useful for presentation to engineering and construction managers. Twenty-two engineers and construction managers, all familiar with cold regions and remote projects, were interviewed, and the information and taxonomy were reviewed with them. This process resulted in a set of preliminary guidelines, which were then presented at two different meetings: one at AGC and one at the DOT, Central Region, where the preliminary guidelines were revised slightly. The final set of guidelines, approximately 160 suggestions and notes, was used to develop a module for UAF construction management classes, although it is suitable for other learning venues. The module, the Guidelines, as well as a preliminary paper are available on the CESTiCC website.
    • A Targeted Approach to High-Volume Fly Ash Concrete Pavement (Phase I)

      Du, Sen; Shi, Xianming (2018-12)
      Unlike the conventional method of admixing nanomaterials directly in fresh concrete mixture, a more targeted approach was explored. Specifically, nanomaterials were used to improve the interface between coarse aggregate and cement paste, by coating the coarse aggregate with cement paste that contained graphene oxide or nanosilica. Using coated coarse aggregates, the mechanical and transport properties of high-volume fly ash (HVFA) concrete were tested to evaluate the effect of nanomaterial coating on the interface transition zone of concrete. The compressive and splitting strengths of HVFA concrete at 3, 7, 14, and 28 days and the water sorptivity and chloride migration coefficient at 28 days were studied. Results show that nanomaterial-coated coarse aggregate can improve the transport properties of HVFA concrete by reducing permeability. However, no improvement was seen in the compressive and splitting strengths when incorporating coated coarse aggregate, compared with direct mixing of nanomaterials in fresh concrete. Resistance to freezing/thawing cycles and scanning electron microscope/energy dispersive X-ray spectroscopy of concrete samples were also investigated to obtain a more comprehensive and mechanistic understanding of nanomaterial coating.
    • Transportation Life Cycle Assessment Synthesis Phase II

      Center for Environmentally Sustainable Transportation in Cold Climates, 2018-04-24
      The Transportation Life Cycle Assessment (LCA) Synthesis includes an LCA Learning Module Series, case studies, and analytics on the use of the modules. The module series is a set of narrated slideshows on topics related to environmental LCA. Phase I produced 27 modules, and Phase II added 10 more. The modules are available for download on the Lamar CEE website https://www.lamar.edu/engineering/civil/faculty/haselbach/lca-modules.html and on the CESTiCC website http://cem.uaf.edu/cesticc/publications/lca.aspx. The modules are around 20 minutes long and may be used for various purposes such as for class lectures or part thereof, and for background learning in research or application. The modules are organized into four topical areas, each containing overview and detailed modules. The A and α groups cover the international standards that define environmental LCA. The B and β groups summarize some of the typical environmental impact categories in LCA. The G and γ groups include software tools for LCA. The T and τ groups focus on the growing field of transportation with respect to LCA, a complex area of importance. The analytics section provides data on downloads of the modules from the websites and summary survey results from course implementation.
    • Transportation Life Cycle Assessment Synthesis: Life Cycle Assessment Learning Module Series

      Haselbach, Liv; Langfitt, Quinn (Center for Environmentally Sustainable Transportation in Cold Climates, 2015-03-12)
      The Life Cycle Assessment Learning Module Series is a set of narrated, self-advancing slideshows on various topics related to environmental life cycle assessment (LCA). This research project produced the first 27 of such modules, which are freely available for download on the CESTiCC website http://cem.uaf.edu/cesticc/publications/lca.aspx. Each module is roughly 15- 20 minutes in length and is intended for various uses such as course components, as the main lecture material in a dedicated LCA course, or for independent learning in support of research projects. The series is organized into four overall topical areas, each of which contain a group of overview modules and a group of detailed modules. The A and α groups cover the international standards that define LCA. The B and β groups focus on environmental impact categories. The G and γ groups identify software tools for LCA and provide some tutorials for their use. The T and τ groups introduce topics of interest in the field of transportation LCA. This includes overviews of how LCA is frequently applied in that sector, literature reviews, specific considerations, and software tutorials. Future modules in this category will feature methodological developments and case studies specific to the transportation sector.
    • Use of Cellular Concrete for Air Convection Embankment to Protect Permafrost Foundations in Cold Regions: Feasibility Study

      Liu, Jenny; Wu, Hanli (2019-08-15)
      The air convection embankment (ACE) is a technique used to protect permafrost from thawing in road construction in cold regions. However, the desired materials needed for ACE are not readily available, which prevents its extensive use in Alaska. To overcome the limitation of traditional ACE, and further improve the cooling effect of ACE, this study investigated the feasibility of using cellular concrete as an alternative material for ACE in cold regions. The heat transfer patterns of the cellular concrete ACE, the crushed-rock ACE, and the sand/gravel embankment were studied using the numerical simulation. The results of the present study show that the cooling performance of both cellular concrete ACE and crushed-rock ACE are superior to the traditional sand/gravel embankment. The cellular concrete ACE has better heat insulation property in the summer, and the crushed-rock ACE has stronger natural convection in winter. For the annual cooling efficiency of the two different ACE techniques, the proposed cellular concrete ACE has a better cooling effect on the foundation soil than the crushed-rock ACE. These results indicate that the thermal conductivity and specific heat capacity of construction materials have significant impacts on the performance of the ACE.