Theses and Dissertations at Montana State University (MSU)
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Item Feasibility of non-proprietary Ultra-High Performance Concrete (UHPC) for use in highway bridges in Montana: phase III implementation(Montana State University - Bozeman, College of Engineering, 2022) Hendricks, Elias Michel; Chairperson, Graduate Committee: Michael BerryUltra-high performance concrete (UHPC) has mechanical and durability properties that far exceed those of conventional concrete. However, using UHPC in conventional concrete applications has been cost prohibitive, with commercially available/proprietary mixes costing approximately 30 times more than conventional concrete. Previous research conducted at MSU developed a nonproprietary UHPC mix design (MT-UHPC) that is significantly less expensive than commercially available mixes and is made with materials readily available in Montana. The focus of the research discussed herein was on the field implementation of MT-UHPC. Specifically, MT-UHPC was used in all field-cast joints on two bridges spanning Trail Creek on Highway 43 outside of Wisdom, MT. This project began with an extensive literature review focused on previous field applications of UHPC. Subsequently, implementation research was performed with the intent of filling several research gaps related to the field application of MT-UHPC. This research investigated the effects that mixing process, batch size, and temperature have on the performance of MT-UHPC. It also developed maturity curves to be used in estimating the early strength gain of MT-UHPC. Trial batches were then conducted on site and placed into joint mockups to confirm and improve the construction methods to be used on the actual bridge project. In this exercise MT-UHPC was mixed using the same methods and under the same environmental conditions expected on the day of construction. MTUHPC was then used in the Trail Creek bridges to connect the precast concrete bridge elements. Overall, this project was a successful demonstration of using a nonproprietary UHPC in field-cast joints for an accelerated bridge construction (ABC) project. All placed UHPC had adequate flows, gained strength quickly, and reached the required minimum compressive strengths. This was accomplished despite an accelerated construction schedule, and despite mixing and placing the material in the field under varied environmental conditions.Item An investigation modeling risk of wildlife-vehicle collisions in Montana, USA(Montana State University - Bozeman, College of Engineering, 2019) Bell, Matthew Andrew; Chairperson, Graduate Committee: Yiyi Wang and Damon Fick (co-chair)Road ecologists and transportation engineers have been exploring new methods to adapt to the environmental and motorist safety concerns involving wildlife-vehicle collisions. There are over one-million crashes with large-bodied wildlife every year in the U.S. that result in substantial property damage and personal injuries. Recent studies modeling these collisions identify where they cluster, and the landscape, road, and driver characteristics that influence the likelihood of a collision along short road corridors and small geographic regions. This research expands on current knowledge and attempts to model the risk of wildlife-vehicle collisions on a large geographic scale. This research investigates different analysis methods and creates predictive models that will estimate the risk of a wildlife-vehicle collision as drivers travel across multiple ecosystems. Different analysis units were created to extract two similar datasets that are modeled against two different response variables -- reported collisions and roadkill locations. Regularization is used to help with feature selection. Negative binomial regression models are built to predict risk. Random forest machine learning helps better understand the percent of variance explained by the variables in each model. A range of statistical measurements were taken to compare the non-nested models. The best performing model is applied to the seasonal division of data. Yearlong and seasonal risk is mapped onto the road network and color-coded to show the differences in risk on Montana's road network. The maps capture the changes in risk throughout the year, they generally match where wildlife-vehicle collisions actually happen, and even coincides with published work on the locations of collision hotspots in Montana. This research is the basis for future complex real-time risk-mapping models that can be integrated into smart technology and developed into on-board driver alert systems. With the advancements of autonomous vehicle, it is possible to incorporate real-time driving data into models that will analyze wildlife-vehicle collision risk based on vehicle location, season, time of day and driving habits. This can increase driver safety by informing them when they are traveling in areas where wildlife-vehicle collisions are more likely to happen, and can be especially helpful while driving on unfamiliar roads.Item Feasibility of non-proprietary ultra-high performance concrete (UHPC) for use in highway bridges in Montana: phase II field application(Montana State University - Bozeman, College of Engineering, 2020) Scherr, Riley James; Chairperson, Graduate Committee: Michael BerryUltra-high performance concrete (UHPC) has properties far exceeding those of conventional concrete. The MDT Bridge Bureau is interested in using UHPC in field-cast joints between precast concrete deck panels. The primary objective of the research discussed herein was to further investigate and develop a non-proprietary UHPC mix developed for use in Montana. Specifically, this research (1) investigated the potential variability in concrete performance related to differences in constituent materials, (2) investigated issues related to the field batching/mixing of the these UHPC mixes, and (3) tested rebar bond strength and its effects on requisite development lengths. Throughout this research project, the different aspects used to test the UHPC performance and prepare the UHPC, further detailed in chapter 3 of this report, are mixing procedures, flow testing, specimen casting, preparation and curing procedures, compression testing, flexure testing, set time estimates, and bond strength/pullout capacity testing. Variations in the source of the constituent materials had fairly minor effect on UHPC performance. Flow generally increased with increasing aggregate moisture content, and the 7- and 28-day compressive strengths generally decreased. Adjusting the mix water to account for the varying aggregate moisture contents did not have a significant effect on flow, but it was observed to slightly increase the compressive strengths in many cases. The UHPC mixes obtained strengths exceeding 10 ksi in the first 24 hours and continued to gain strength over the duration of testing, ultimately reaching strengths of around 20 ksi at 182 days. Batch size did not have a significant effect on flow or compressive strength; however, larger scale mixes required 10% more water and HRWR in order to obtain the same performance when size was increased from 0.2 cu. ft. to 2.5 cu. ft. or larger. Flow was observed to decrease with increasing temperature, while the compressive strengths for the hottest mix were consistently the lowest. The reinforcement that met the minimum FHWA recommendations all reached maximum applied pullout stresses above the rebar yield strengths. This indicates that the FHWA embedment depth recommendations should be suitable for use in the purposed bridge closure pours with this research's developed UHPC mix.Item An investigation of operational performance on two-lane highways(Montana State University - Bozeman, College of Engineering, 2018) Jafari, Amirhossein; Chairperson, Graduate Committee: Ahmed Al-KaisyA high percentage of the US road networks are two-lane highways. The Highway Capacity Manual (HCM) is the standard reference used in the US for traffic analysis of such highways (HCM 2016). This manual uses a qualitative measure called 'Level of Service (LOS)' to show the quality of traffic flow on the highway network. Performance measures are used as indicators of the LOS in the HCM. The current manual uses Average Travel Speed (ATS), Percent Time Spent Following (PTSF), and Percent Free Flow Speed (PFFS) for measuring LOS on two-lane highways. However, several studies reported that the HCM methodology falls short in several aspects including the performance measure used for operational analysis on two-lane highways. Moreover, the current guidelines of the HCM regarding passing lanes are very limited and based on studies conducted more than three decades ago (Harwood and St. John 1985, 1986). Constructing a passing lane is expensive and there is a need to use accurate methods for the design of such facilities. Therefore, the goal of this study is to examine new performance measures for operational analyses of two-lane highways as well as developing new guidelines for the design of passing lanes. Multiple investigations were conducted using field data from four states in the US as well as microscopic traffic simulation software, SwashSim. Using field data and statistical analysis as well as the results of a survey, the most appropriate performance measures were selected. Additionally, traffic simulation software was used to investigate the operational improvement of passing lanes. Optimum length and effective length of passing lanes were investigated. Optimum length has been used to refer to the length that would bring most operational benefits given the amount of passing lane investments while effective length is defined as the length of two-lane highway over which the effect of a passing lane extends. Moreover, the operational efficiency of different passing lane design configurations were examined to identify the most appropriate length and spacing to be used in the planning and design of passing lanes. In addition, the operational performance of 2+1 roads was investigated in this study and some guidelines for design of these facilities are provided. 2+ 1 highways have one lane in each direction of travel and the middle lane alternates between the two directions.Item Vehicles, grooming, and other factors affecting snowroad longevity in Yellowstone National Park(Montana State University - Bozeman, College of Engineering, 2018) Nelson, Molly McKellar; Chairperson, Graduate Committee: Edward E. AdamsIn winter, the National Park Service (NPS) at Yellowstone grooms snow that builds up on the park roads, making 'snowroads' passable by snowmobiles and snowcoaches. The NPS has recently allowed experimental snowcoaches on low-pressure tires (LPTs) in addition to traditional tracks. As they consider a permanent policy on these LPTS, they want to understand these vehicles' impacts on snowroads compared with those of traditional tracked vehicles and snowmobiles. They also want to know how to optimize other operations (e.g., grooming) to maintain quality roads that support safe travel through the park. This two-year field study investigated the snowroad quality in the park and factors influencing this quality. The approach involved data collection on both parkwide road conditions and individual vehicle passes. Both controllable and non-controllable factors were considered to provide information on their relative influence. Parkwide road quality analysis involved collecting GPS data on grooming activity, weather data from existing stations, road depth through radar measurements, traffic counts from motion-sensor cameras, hardness data, and snow sample analysis. The vehicle-by-vehicle impact study involved both subsurface and surface measurements in the road. Load cells, accelerometers, a high-speed, high-definition camera, a penetrometer, and a 'profilometer' provided measurements. Data analysis combined with existing literature provided insights into best practices for the NPS. Parkwide, snowroads harden throughout the season, with temperatures and traffic load being contributing factors. Grooming results in a harder road if snow disaggregation is followed by compaction, and with a longer set time between grooming and traffic. Individual vehicles' impacts are driven by surface interaction rather than motion at depth in the snowroad. On hard, groomed snowroads, both tracked and LPT snowcoaches can form ruts, but tracked vehicles continue to dig ruts deeper whereas LPT coaches' ruts level out and stop deepening with subsequent passes. This seems to be because LPTs form ruts primarily through compaction and tracked vehicles through snow displacement. Reduced tire pressures reduce rut formation and can harden the road. Results from this study demonstrate that LPT coaches should not be disallowed from Yellowstone based on road impacts. Other results will inform NPS operations to optimize grooming practices.Item The development and validation of a snow/icepack pavement temperature thermodynamic model(Montana State University - Bozeman, College of Engineering, 2002) Bristow, Jeffrey RyanItem A feasibility case study of Automated Highway Systems in the Greater Yellowstone priority corridor(Montana State University - Bozeman, College of Engineering, 1998) Gomke, Russell ScottItem Estimating quality of traffic flow on two-lane highways(Montana State University - Bozeman, College of Engineering, 2008) Karjala, Sarah Renee; Chairperson, Graduate Committee: Ahmed Al-KaisySince the publication of the 2000 Highway Capacity Manual (HCM), there have been several studies that indicate that the HCM equations for Percent Time-Spent- Following (PTSF) on two-lane highways do not correspond to field-based measurements. This discrepancy was the motivation for this research project. The purpose of this project was two-fold. First, it aimed to find an alternative performance measure to PTSF that could be measured directly in the field and could adequately describe the quality of traffic flow. Secondly, the project aimed to investigate the inter-vehicular interaction between consecutive vehicles traveling on the same lane of two-lane rural highways. Both studies were empirical in nature and utilized field data gathered from rural two-lane and four-lane highways in the state of Montana. Six performance measures for two-lane highways were investigated; they were: average travel speed, average travel speed of passenger cars, average travel speed as a percent of free-flow speed, average travel speed of passenger cars as a percent of free-flow speed of passenger cars, percent followers, and follower density. The performance measures were evaluated based on their level of association with major platooning variables. Among all performance measures investigated, follower density and percent followers exhibited the highest correlation to platooning variables, respectively. Overall, follower density was recommended as the best performance measure for two-lane highways. Based on the fact that follower density is a headway-based service measure, the second study aimed to achieve a better understanding of car-following interaction on two-lane rural highways. Car-following interaction was studied by examining headway distributions, speed-headway relationships, and percent followers and flow relationships. The study found that car-following interaction generally ceases when headways exceed a value of approximately six seconds. Also, a significant proportion of drivers choose to maintain relatively short headways while following other vehicles on two-lane highways regardless of passing restrictions.