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Investigation Into The Effect Of Mixture Composition On Setting Time Of Magnesium Phosphate Cement, Autumn Broglen

Civil Engineering Undergraduate Honors Theses

Magnesium phosphate cement (MPC) is a cementitious material that is formed through an acid-base reaction between magnesia and phosphate. This reaction occurs rapidly, making MPC an appealing choice for rapid repair applications. The purpose of this project is to investigate the impact of different proportions of class F fly ash, set retarder consisting of a mixture of boric acid and dextrose, magnesium to phosphate ratio, and water/cement ratio on the initial setting time of MPC paste. Different mixtures of MPC paste were developed to vary the proportions of each constituent, and setting time of each mixture was determined using the …

Effect Of Swirl Ratio On Simulated Vortech Chamber Vortex Parameters, Samuel Kolar

Civil Engineering Undergraduate Honors Theses

A numerical simulator can use computational fluid dynamics (CFD) to model an experimental tornado-simulating chamber at Texas Tech University (known as VorTECH). Previous studies evaluating this particular CFD model have produced results that compare the touchdown swirl ratio (S_TD), core radius (r_c), maximum tangential velocity at touchdown (V_tmax @ S_TD), and height of the maximum tangential velocity (z_c) reasonably well with experimental data from the VorTECH facility. The effects of swirl ratio beyond S_TD on important vortex parameters including r_c, V_tmax, z …

Innovations In Football Protective Headgear, Henry Bethel

Civil Engineering Undergraduate Honors Theses

Adding impact reduction to football protective headgear decreases the reactionary acceleration experienced by the cranium. Utilizing an iteration of the National Operating Committee for Standards in Athletic Equipment (NOCSAE) method of testing per ASTM F429, a drop tower was fabricated, and 27 drop tests were conducted upon a standard helmet (control) and the Summerlin model helmet (test), measuring the maximum acceleration experienced by each drop. Drop tests involved variable heights and test angles with three drops being made per combination. The Summerlin model drops were conducted until failure, occurring at the third 3” drop at the “front” location at an …

Photocatalytic Nanoparticle Treatment Of Cyanotoxins In Harmful Algal Blooms, Brian Baird

Civil Engineering Undergraduate Honors Theses

Harmful Algal Blooms (HAB) have the ability to cause detriment to water bodies, ecosystems, and human health. Furthermore, current evidence suggests that these events are becoming increasingly common due to factors such as increased pollution and global warming. While there are current methods to treat water that is negatively impacted by the bacteria and toxins associated with HABs, these methods are often costly and inefficient. The purpose of this research is to explore a potential treatment option that uses titanium dioxide photocatalytic nanoparticles attached to a retractable net to treat toxins produced by HABs in situ. Specifically, the toxin …

Understanding The Bond Strength Of Bcsa Cement Repair Concrete To Portland Cement Concrete, Brenden Simmons

Civil Engineering Undergraduate Honors Theses

Concrete structures deteriorate over time, and there is an increasing demand for quick repair solutions. Belitic calcium sulfoaluminate (BCSA) cement, a type of rapid setting cement, is thought to be a more sustainable and convenient alternative to portland cement in repair concrete applications. Indicated by the name, rapid setting concrete can set up quicker than traditional portland cement concrete. Because of this, there has been a lot of research about the properties of rapid setting concrete mixes. One of the most popular topics is the strength of the concrete itself. However, there is a need for more research to understand …

Investigation Of Micp Based 3d Printed Soils, Kathleen Weston

Civil Engineering Undergraduate Honors Theses

The advent of additive manufacturing, often called 3D printing, offers potential for new and more sustainable soil improvement techniques. Previous research at the University of Arkansas has examined Microbially Induced Calcite Precipitation (MICP) as a possible binder option that is a more sustainable alternative to Portland cement and can be used in remote areas where Portland cement may not be available. The objective of this research is to develop an increased understanding of the potential of utilizing MICP as a spray binding technique for applications in 3D printed soils. The specific goals of this research include: examining the effectiveness of …

Impacts Of Diagonal Crosswalk Misuse, Elizabeth Francis

Civil Engineering Undergraduate Honors Theses

A diagonal crosswalk paired with an all-red phase traffic signal is an effective approach to manage intersections with high pedestrian volume. This allows pedestrians to cross both north-south and east-west bound roads at the same time. However, ineffective diagonal crosswalk marking, and lack of signs reduces the use of diagonal crosswalks which in turn results in jaywalking, often in unsafe capacities. The objective of this study is to determine the impacts of pedestrian-caused delay and safety impacts due to the misuse of a diagonal crosswalk. To better understand the impacts, a camera-based data collection was conducted during a four-hour period …

Comparing The Stiffness Of Cold In-Place Recycled Asphalt Pavement To Hot Mix Asphalt: Determining The Reproducibility Of The Stiffness Rebound Test, Tanner Turben

Civil Engineering Undergraduate Honors Theses

The Stiffness Raveling Mechanism Test (SRMT) was originally developed as an indirect measure of pavement stiffness to determine a pavement’s tendency to ravel, a type of damage. Regarding rehabilitation of existing roadways by Full Depth Reclamation (FDR) Cold In-Place Recycling (CIR), concern of field repeatability was expressed (Hill & Braham, 2016).

An analysis of lab-compacted samples of CIR and Hot Mix Asphalt (HMA) was performed to determine if the results could be reproduced between CIR and HMA. Additionally, the experiment observed the effects of percent air voids, temperature, and moisture conditioning on CIR and HMA. Three samples were prepared for …

Evaluating The Effects Of Curing Methods On Bcsa Cement Concrete, Hannah Allen

Civil Engineering Undergraduate Honors Theses

BCSA cement is a type of cement that makes concrete set up much quicker than typical portland cement concrete. BCSA cement concrete also has a much higher compressive strength than that of portland cement concrete. This study was conducted to determine the effect of different curing conditions on the compressive strength of BCSA cement concrete.

Community Transportation Needs And Willingness To Use Shared Micromobility: A Case Study Of Fort Smith, Arkansas, Anthony Michael Kammerer

Civil Engineering Undergraduate Honors Theses

Shared micromobility is utilized in “targeted service areas with the usage generally intended for short trips such as "first- and last-mile" connections to complete trips made via other modes, including transit” (Price et al., 2021). In the United States, this practice has especially taken off with the implementation of sharing-based systems. This is evidenced by ridership numbers in the United States growing from 84 million riders nationwide in 2018 to 136 million riders in 2019 (NACTO, 2020). Users often use their smart phone or another similar device to unlock the vehicle after paying a fee on the device through their …

Wave Interactions And Energy Cascade, Bailey Downing

Civil Engineering Undergraduate Honors Theses

Structural engineers design buildings and their components to withstand code-specified wind loads. The ASCE 7-16 manual sets the standards for calculating wind loads in the U.S. Depending on the velocity of wind, deflections may occur as wind passes through the building. The pressure reported from ASCE are based on wind tunnel measurements. The peak pressure from ASCE 7 is much less than what is measured from the field for a low-rise building. As an alternative economic tool, Computer modeling has been developed to help with this dilemma. Methods based on computational fluid dynamics (CFD) are used to calculate velocities and …

Determining Earthquake Impacts On Arkansas' Roadway Network: An Application Of Hazus., Simon Rothwell

Civil Engineering Undergraduate Honors Theses

Natural hazards are a dangerous and unpredictable aspect of life on earth. They can cause devastating damage to our surroundings that makes movement of people, goods, and emergency services difficult. There is a need to plan for these disasters to ensure that damages to our infrastructure and people are minimized. It can be difficult for planners to determine which parts of a roadway network are most vulnerable to a specific disaster and what their impact on the rest of the network may be. This thesis uses a nationally available natural disaster estimation tool developed by FEMA called “Hazus” (FEMA, 2020). …

Design Of A Freight Transportation Outreach Curriculum, Breanna Stoesz

Civil Engineering Undergraduate Honors Theses

This project is centered around finding a solution to the shortage of truck drivers within the freight industry. Specifically, this project aims to lessen this shortage by ensuring potential future drivers are aware of the benefits of the industry and are encouraged to consider this career path for themselves. By producing an engaging and educational freight transportation curriculum for middle and high school students to go through in outreach programs, these students would have an increased likelihood of joining the trucking profession and encourage others to become informed about the profession as well. In addition to the direct driving role, …

Strain Measurements In Skewed Reduced Beam Section Special Moment Frame Connections, Elizabeth Moriconi

Civil Engineering Undergraduate Honors Theses

A series of experimental tests were conducted in the Civil Engineering Research and Education Center (CEREC) at the University of Arkansas to evaluate the effect of beam skew on a reduced beam section. Various degrees of skew on deep and shallow column depths were tested following a cyclical loading protocol, established by the AISC Seismic Provisions, to analyze the capacity of the out-of-plane skew connection [1]. Using the prequalified cyclical loading protocol allows for the evaluation of SMF connections in skew configurations against seismic events. Strain distributions throughout the RBS section, the welded beam-column connection, and the column flange were …

The Effect Of Changing Land Use On Streamflow Statistics And Flood Flows Across Select Gages In Northwest Arkansas, Timothy Mcmullen

Civil Engineering Undergraduate Honors Theses

Since 1901, heavy rainfall events have increased in the United States in both intensity and frequency, and population in the United States has increased, resulting in significant land use changes. Both of these trends could explain an increase in observed flood magnitude and frequency. In order to determine if a relationship exists between land use/land cover and changing stream flows in northwest Arkansas, this study analyzed temporal changes in various flow statistics for fourteen stream gages and compared the rates of change in flow statistics from gages on streams with watersheds that have varying land uses, i.e. urban, agricultural, and …

Relating The Dongre Workability Test To Cold In-Place Recycled Asphalt Pavements, Gus Williams

Civil Engineering Undergraduate Honors Theses

The Dongre Workability Test (DWT) is a test for determining an asphalt pavement’s relative workability from the stress-strain curve of a sample. While the DWT has seen favorable results with warm mix and hot mix asphalt, Casillas and Braham (2020) attempted to apply this test to cold in-place recycled (CIR) asphalt pavements with limited results. This paper looked at the process of reexamining the DWT method to more favorable results with CIR samples. Phase 1 consisted of defining ten possible metrics from the stress-strain curve and applying them to samples with three different curing conditions. From these preliminary results, the …

Analysis Of Shear-Strength In Weathered Shale Strata Along A Highway Slope Failure Site In Northwest Arkansas, Olivia Overton

Civil Engineering Undergraduate Honors Theses

Slope failures cost millions of dollars per year to repair and can be deadly. Accurate modeling of slope conditions, including soil parameters, water table locations, and depth to bedrock, are essential to determining the overall stability of a slope. This project is a continuation of the work completed in 2019 by a former University of Arkansas researcher, Vanessa LeBow. LeBow RocScience used Slide2 modeling software to model two highway embankment slopes in Northwest Arkansas that experienced slope movement to determine whether increased use of geophysical data could increase the accuracy of slope stability models. A parametric study of shear strengths …

Exploring The Variability In The Gray Scale Imaging Process Of Asphalt Samples, David Oluwawade Olatunji

Civil Engineering Undergraduate Honors Theses

Gray scale image analysis is a powerful tool for testing asphalt concrete materials. From material composition to surface properties, gray scale analysis has shown evidence as a non-invasive way to obtain information from asphalt samples. Casillas et al. used a gray scale analysis to measure the Representative Volume Element of three asphalt sample geometries to understand the minimum size at which an asphalt sample is representative of a larger homogeneous mixture [1]. While the gray scale analysis used in this experiment yielded results, there were unknown factors in the image capturing process. Particularly, not much was known about the effect …

Multiaxial Fatigue Of Notched Steel Plates And Investigation Of Cfrp Retrofits For Crack Initiation Prevention, Ayumi Fujii

Civil Engineering Undergraduate Honors Theses

Fatigue cracks are cracks that result from repeated loading over time, often following millions of loading cycles. Fatigue cracks occur even if the applied load is not large enough to cause material yield. Once a fatigue crack initiates, resulting stress concentrations at the crack tip often make it difficult to arrest the growth of the crack. In order to prevent growth and propagation of fatigue cracks within structural components, it is necessary to alter the stress condition at the crack tip. Fatigue cracks in steel structures resulting from multiaxial loading and or geometry conditions that result in complex states of …

Applying Performance Engineered Mixture Design To Permeable Concrete, Rachel Pohl

Civil Engineering Undergraduate Honors Theses

The scope of research and application related to permeable pavements has recently broadened. The desire to significantly reduce the environmental impact of large paved areas makes the permeable pavement concept more desirable (American Concrete Institute, 2018). Although research and interest are increasing, the actual application of permeable pavement is still very limited and has not reached the airfield arena. In airfields, permeable pavement could possibly be used for aircraft aprons - which currently require substantial measures to control stormwater runoff. Permeable pavements are typically used in low-traffic-volume / lightly loaded applications; questions remain regarding a permeable pavement’s ability to hold …

Extremely Low Cycle Fatigue Behavior Of Additively Manufactured 17-4ph Stainless Steel, Kaley Collins

Civil Engineering Undergraduate Honors Theses

Steel structures survive seismic loading thanks to components capable of dissipating large amounts of energy through large deformations. Future optimizations of these components include complex free-form geometries that are difficult to fabricate with traditional casting processes. Additive manufacturing (AM) is an alternative for producing optimized free-form geometries. AM material contains significant differences in microstructural characteristics and mechanical behavior compared to its wrought counterparts. Research has been conducted to understand the effect of microscopic features in the high cycle fatigue (HCF) and low cycle fatigue (LCF) regimes. This study focuses on the behavior of 17-4 Precipitation Hardening (PH) stainless steel in …

Countermeasures For Pedestrian-Involved Accidents On Interstate-Highways, Anna C. Hunter

Civil Engineering Undergraduate Honors Theses

Pedestrian access to the Interstate is prohibited, but many pedestrian-involved accidents still occur on the Interstate in the United States. This project is a case study of West Memphis, Arkansas, which has the second highest occurrence of pedestrian-involved accidents on the Interstate in Arkansas. The study site location includes a segment of Interstate I-40 which is at- grade. The surrounding area contains several different land-uses, which is believed to be the primary generator of these accidents. The goal of this project is to determine the primary causes of these accidents and determine potential countermeasures to reduce the crash rate for …

Soil Moisture Content Determination By Means Of The Electromagnetic Spectrum, Julia Loshelder

Civil Engineering Undergraduate Honors Theses

Soil moisture content provides information about the strength, permeability, and compressibility of the soil under investigation. In the research described herein, the relationship between moisture content and reflectance values obtained from spectroscopy was developed to investigate whether in-situ moisture content can be determined in a faster and more efficient way than the current methods. The soil under investigation was laboratory-compacted kaolinite clay mixed with pyranine dye. These specimens were placed beneath an ultraviolet light and a halogen illuminator where reflectance values were collected over a 24-hour period. Correlations were developed from the following methods: 1) spectral indices, 2) continuum analyses …

Understanding Workability In Belitic Calcium Sulfoaluminate Concrete Mixtures, Caleb W. Chesnut

Civil Engineering Undergraduate Honors Theses

Belitic Calcium Sulfoaluminate cement (BCSA) is an emerging technology in the concrete industry. BCSA has similar hardened properties to portland cement (PC) but can set in under 20 minutes and reach 4,000 psi in less than 2 hours. Portland cement accounts for 8% of the world’s CO2 emissions, BCSA cements require less energy to produce. Studies have shown that 40% less CO2 is emitted during the production of BCSA cement than portland cement. This environmental benefit also makes it a very promising PC alternative. Before a new material can be used, designers need to understand the material’s properties. The goal …

Preliminary Investigation Of Required Bsca Amount For Soil Cement Mixtures, Mariel Mayori Rivero

Civil Engineering Undergraduate Honors Theses

The recent increase of flooding in the United States and the high expenses related to the damage that these floods have caused to waterway structures suggests a potential interest in rapid setting soil cement to make effective repairs. For this thesis, mix designs of soil only at three different sand-clay proportions were prepared and tested for moisture content and maximum dry density. Due to the early closing of the laboratory and research activities, reliable results were collected from the 70% sand and 30% clay proportions. At those proportions of soil, the optimum moisture content was found to be 8.88% with …

Development Of A Ground-Based Aerial-Tracking Instrument For Open-Path Spectroscopy To Monitor Atmospheric Constituents, Haden Hodges

Civil Engineering Undergraduate Honors Theses

A ground-based aerial-tracking instrument, known as the Ground Tracker, designed to provide spectral data to quantify greenhouse gases is under development. The Ground Tracker includes an Optical System including a high power rifle scope, video camera, and spectrometer used to locate an active light source from the Emitter, and collect spectral data by utilizing an actuating mirror. The implementation of this instrument could be made low cost by utilizing existing weather balloon infrastructure to allow the Emitter to be placed into the lower stratosphere. The recovery of the emitter will be possible by tracking the GPS coordinates. Weather balloon instrument …

Displacement Derived Energy Levels For Harvard Miniature Compaction, Ana Laura Errigo, Julia Loshelder

Civil Engineering Undergraduate Honors Theses

Previously, the amount of energy provided by the Harvard Miniature tamper was adjusted by changing the number of blows per lift or the number of lifts or was not adjusted at all. However, this research was conducted to investigate the effect of adjusting the displacement of the spring (increased or decreased) to change the potential energy of the spring and therefore change the compacive effort with a specific type of soil. Thus, the objective was to match the compaction energies using the Harvard miniature method with the compaction energies obtained using the Proctor method. Specifically, the goal was to show …

Development Of A Mechanical Device For Measuring Connection Rotations During Seismic Loading, Garrett Tatum

Civil Engineering Undergraduate Honors Theses

This engineering design project sought to design a cheap and easy-to-use sensor to monitor seismic connection rotations in steel buildings during earthquakes by using a linear ratchet mechanism. The idea for the project goes against the mainstream of research that is seeking to develop complex digital networks for monitoring structures in earthquake regions. Whereas many modern sensor networks require high-cost, professionally maintained digital networks, an analog sensor could provide much of the same information at a fraction of the cost, allowing sensors to be more widely utilized, particularly in developing countries. This project required an iterative engineering design process to …

Turbulent Effects On Building Pressure Using A Two-Dimensional Finite Element Program, Jonese Woods

Civil Engineering Undergraduate Honors Theses

Much of the knowledge about building aerodynamics today was obtained from physical testing like wind tunnel testing. Physical testing is time-consuming and very expensive. As a result, computational methods like the finite element method are being explored for use in building aerodynamics. Despite several years of research, there is still not a clear understanding of the peak pressure on buildings due to turbulence. Many of the research thus far has focused on comparing different computational methods. However, much work is needed in understanding the capability of the individual methods. In this work, a two-dimensional finite element program is used to …

Probable Maximum Flood Estimation Using A Statistical Approach And A Storm Model Approach For A Watershed In Southern St. Vincent, Khandi Gordon

Civil Engineering Undergraduate Honors Theses

With the increase in frequency and severity of flooding due to natural events, there is an increased need for flood studies in order to mitigate the effects of flooding. Some of the most vulnerable countries to flooding are Small Island Developing States (SIDS). These countries face many common development challenges, including geographic and economic isolation, limited resources, environmental fragility, high costs of transportation and energy, and vulnerability to climate change and natural disasters. This project focuses on estimating the probable maximum flood (PMF) for a watershed in a SIDS. To find PMF, the probable maximum precipitation (PMP) is needed. Two …