Digital Commons Network^™

Utilizing Unmanned Aerial Vehicles (Uavs) For The Estimation Of Beam Corrosion Of Steel Bridge Girders, Gabrielle Pryor

Masters Theses

The transportation infrastructure in the United States is a complex system that is vital to the everyday operations of the country. Bridges are a significant asset of this network, with many of them approaching the end of their service life. Corrosion is a common cause of deterioration which ultimately results to structural deficiency for the aging bridges. The deterioration rate is a multi-aspect factor that makes bridge inspections crucial. However, the current bridge inspections are very costly and potentially unsafe for the involved personnel. To lower costs and increase safety, many state DOT’s and universities have decided to perform research …

Effect Of Spike Anchors On The Bond Behavior Of Steel Reinforced Polymer Composite Externally Bonded To A Concrete Substrate, Keenan Lorence Mcburney

Masters Theses

Steel reinforced polymer (SRP) composites are a strengthening material that consist of continuous high-strength steel cords embedded in a polymeric matrix. SRP has demonstrated a high potential for providing additional flexural and shear strength in existing concrete structures when bonded to the concrete surface. However, premature debonding from the concrete substrate at low load levels is a major shortcoming of SRP composites. It has been demonstrated in previous studies that anchors can limit the effect of debonding in fiber reinforced polymer (FRP) composites by increasing the load capacity and ductility of the composite-concrete interface.

This study aims to investigate the …

Early Wildfire Detection By Air Quality Sensors On Unmanned Aerial Vehicles: Optimization And Feasibility, Doaa Rjoub

Masters Theses

“Millions of acres of forests are destroyed by wildfires every year, causing ecological, environmental, and economical losses. The recent wildfires in Australia and the Western U.S. smothered multiple states with more than fifty million acres charred by the blazes. The warmer and drier climate makes scientists expect increases in the severity and frequency of wildfires and the associated risks in the future. These inescapable crises highlight the urgent need for early detection and prevention of wildfires. This work proposed an energy management framework that integrated unmanned aerial vehicle (UAV) with air quality sensors for early wildfire detection and forest monitoring. …

Optimization Of Transit Smart Card Data Publishing Based On Differential Privacy, Chenxi Chen

Masters Theses

“Privacy budget allocation is a key step of the differential privacy (DP)-based privacy-preserving data publishing (PPDP) algorithm development, as it directly impacts the data utility of the released dataset. This research describes the development of an optimal privacy budget allocation algorithm for transit smart card data publishing, with the goal of publishing non-interactive sanitized trajectory data under a differential privacy definition. To this end, after storing the smart card trajectory data with a prefix tree structure, a query probability model is built to quantitatively measure the probability of a trajectory location pair being queried. Next, privacy budget is calculated for …

Numerical Behavior Of Steel H-Plies Repaired Using Layered Concrete Jacket, Fareh Waleed Abudawaba

Masters Theses

“This study developed finite element models (FEMs), using LS-Dyna software, to investigate the repair of corroded steel H-piles using concrete jacket. The concrete modeled as a layered material simulating 3D printed concrete. 3DPC is a new technology that can be used to repair or build structures without formwork by depositing concrete mixture layer by layer. For the 3DPC, this study investigated the feasibility of using alkali-activated concrete (AAC) synthesized using class C fly ash as the main binder. The fresh properties, extrudability, and buildability of the proposed concrete were investigated through open time and deformation tests, respectively. Hardened properties were …

Axial Performance Of Self-Consolidating Concrete-Filled Fiber Tubes, Joshua David Carter

Masters Theses

"Concrete filled fiber tubes can be used to increase ductility and strength of a concrete member and self-consolidating concrete is an ideal material to use in practical applications of concrete-filled fiber tubular columns. However, the propensity of self-consolidating concrete to autogenous shrinkage could reduce the effectiveness of the concrete confinement. This research investigates the use of self-consolidating concrete in pre-cast FRP tubes and various methods of shrinkage reduction and compensation to increase the axial performance of said self-consolidating concrete-filled fiber tubes. Axial compression tests were performed under monotonic and cyclic conditions to determine the stress-strain relationship of the self-consolidating concrete …

A Cfd Study Of Operation Room Air Conditioning: Air Curtain Performance, Spencer Lee Boer

Masters Theses

An operation room is a critical environment when it comes to the safety of patients undergoing surgery. There are a lot of factors that go into reducing Surgical Site Infections (SSI) following a surgery. This comes in the form of cleaning standards, surgical practices, but also environment controls. The characteristics of airflow within an operation room are related to the risk of an SSI. Some of these factors are temperature, velocity, and turbulent air around an open wound which could increase the chance of bacteria or other particles entering the very vulnerable patient. As clean room standards continue to be …

Biaxial Behavior And Design Of Steel-Concrete Composite Columns, Amirfarzad Behnam

Masters Theses

Steel-concrete composite columns are efficient structural members that possess significant strength, stiffness, and ductility. Accurate methods of assessing the strength of these members are necessary to realize their benefits. Several design codes rely on the plastic stress distribution method (PSD) for computing the cross-sectional strength of composite columns subjected to axial compression and flexural bending. However, there has been limited validation of this method over the wide range of material and geometric properties and loading conditions to which it is permitted to be applied. The first part of this thesis presents a study of the behavior of short composite columns …

High-Resolution Timeseries Analysis Of Dynamic Geochemistry: A 27-Well Survey Of Contaminated Groundwater Downstream Of The Former S-3 Ponds, Oak Ridge, Tennessee, Emma Dixon

Masters Theses

Spatiotemporal variability of geochemistry of contaminated groundwater has large implications on overall water quality and ability to respond to remedial applications. Gaining knowledge of how geochemistry changes over time in an area can help establish response trends to changing external conditions like weather and level of contamination. In this study, a spatiotemporal survey was performed on 27 wells at the Y-12 Complex in Oak Ridge, Tennessee. This was completed to measure diurnal fluxes in geochemistry from seasonal changes and extreme weather conditions in three areas of historically different contamination levels from a single point contamination source. Measurements were gathered over …

Lagrangian Bedload Movement Prediction Using The Virtual Velocity Approach, Theodoros Kyriakopoulos

Masters Theses

The advances in particle tracking codes in the recent years has made possible to track the intermittent movement of a large number of sediment particles with precision and in an automated way. The present study used this technique to study the velocity of the particle while it is in motion, the length it travels once it gets mobilized until it deposits, and the time it rests once deposited until it gets mobilized again. New modeling equations were developed to predict these quantities for a wide range of flow conditions and sediment sizes. These equations were combined to predict the virtual …

Improving Stream Bank Erosion Estimates By Adjusting The Applied Shear Stress For Different Bank Characteristics, Justin Condon

Masters Theses

Stream bank erosion rates are commonly modeled using the excess shear stress equation ε_r = k_d(τ-τ_c)^a, where the exponent a is assumed to be unity. The coefficient of erodibility k_d, and the critical shear stress τ_c [Tau _c] are properties of the bank soil and the applied shear stress τ [Tau] is a function of the channel geometry and discharge. This equation appears to overstimate bank erosion likely due to effects of channel morphology and bank vegetation, among other factors. The objective of this study was to determine whether …

School Bus Routing To Allow Later School Start Times, Rana Eslamifard

Masters Theses

School districts providing busing services for students who live too far to walk to school. In many districts a fleet of school buses is used in sequence to transport high school students, then middle school students, and then elementary school students. The result is that high school classes must start much earlier in the morning than the elementary school, and buses may traverse similar routes three times each morning and afternoon. In light of recent research on the benefits of later high school start times and the need to control transportation costs, school districts are seeking efficient school bus routing …

Modeling Of Electrical Grid Systems To Evaluate Sustainable Electricity Generation In Pakistan, Muhammad Mustafa Amjad

Masters Theses

Pakistan has always had a history of severe energy shortfalls, which rose up to an alarming 33% in 2013. This situation was countered by investments in the energy sector through the China Pakistan Economic Corridor (CPEC), which were unfortunately largely based on brown fuels. Although beneficial in the short term, these investments do not bode well for the climate scenario of Pakistan, with various parts of the country already having experienced temperatures rise of 1-3°C. To ensure that the current situation doesn’t exacerbate and is tackled in a timely manner, this research aims to examine how the untapped potential of …

Numerical Performance Evaluation Of The Wooden Frame Structures With Adhesive Applied Connection Under Wind And Seismic Loading, Sharthak Bhandary

Masters Theses

The objective of the research is divided into two folds. The first objective is to study the state-of-the-art modeling method for the wooden frame construction, while the second objective is to evaluate the performance of a wooden frame structure with construction adhesives under hazardous loading conditions using the selected numerical modeling method. The numerical modeling tools were classified under academic and commercial categories based on the purpose of their development. Both academic and commercial tools were further classified based on model types of the structural systems (i.e., shear walls and three-dimensional (3D) buildings) and the applied loads (i.e., wind loading …

Quantification Of Thermal Bridging Effects In Cold-Formed Steel Wall Assemblies, Divyansh Kapoor

Masters Theses

Thermal bridging can be defined as the phenomenon where a structural element spanning the building envelope acts like a thermal pathway which collects and moves energy (heat) from the interior to the exterior of the structure. CFS construction, due to the high thermal conductivity of steel with respect to its surrounding structural components and repetitive nature of framing, is highly prone to thermal bridging. Thermal bridging significantly alters the thermal performance of wall assemblies.

Hence, the objective of this research project was to quantify the magnitude of energy loss through cold-formed steel (CFS) stud wall assemblies at a component level …

Vehicle Performance Analysis Of An Autonomous Electric Shuttle Modified For Wheelchair Accessibility, Johan Fanas Rojas

Masters Theses

Autonomous vehicles (AV) have the potential to vastly improve independent, safe, and cost-effective mobility options for individuals with disabilities. However, accessibility considerations are often overlooked in the early stages of design, resulting in AVs that are inaccessible to people with disabilities. The needs of wheeled mobility device users can cause significant vehicle design changes due to requirements for stepless ingress/egress and increased space for onboard circulation and securement. Vehicles serving people with disabilities typically require costly aftermarket modifications for accessibility, which may have unforeseen impacts on vehicle performance and safety, particularly in the case of automated vehicles. In this research, …

Feasibility Study On Novel Fire-Resistant Coating Materials, Anyou Zhu

Masters Theses

“Over the past decades, wildfires in the United States have caused severe damage and property losses. The California Camp Fire in November 2018 caused 85 civilian fatalities and destroyed 18,793 structures. There is a need to enhance the fire resistance of structures and buildings. The primary purpose of this study was to develop innovative surface-bonded fire-resistant material that can be used as a wall coating with three primary features: (a) workability for application, (b) enough adhesion to the surface of the structure, (c) fire-resistant. This research developed mix designs of innovative fire-resistant coating materials including high-performance cement mortar (HPCM), geopolymer …

Experimental Evaluation Of A Honeycomb Structure In Open Channel Flows, Kyle David Hix

Masters Theses

“Designing and controlling open channel flows presents many challenges. One such challenge is energy dissipation. This challenge is currently addressed by several means, including the use of honeycomb structures. Energy dissipation by honeycomb structures has been studied for pressurized conduit flows; however, their ability to dissipate energy in free-surface flows remains largely unexamined. This work introduces a comprehensive experimental study designed to estimate the energy dissipation through a honeycomb structure in a free-surface flow.

This work examined the energy dissipation for a range of flows, pipe lengths, and pipe diameters in two flumes. PVC pipes ranging from 6 inches to …

Soil-Water-Energy Nexus Of Green Roofs, Katherine Ann Bartels

Masters Theses

"As the urban landscape continues to sprawl into previously undeveloped land to accommodate population growth, the need to design cities that effectively manage urban stormwater is imperative for a sustainable future. Green roofs use rain-harvesting techniques to reduce urban stormwater discharge while simultaneously providing traditional roof services as well as several ecosystem services. However, green roof media design varies greatly among commercial applications, and little guidance is available to engineers when selecting the media for prospective green roofs. Efforts to maximize stormwater retention and enhance urban heat island mitigation capabilities of green roofs while concurrently reducing nutrient loading were examined …

Optical Fiber Based Integrity Test Of Civil Engineering Materials: Numerical Analysis, Ruoyu Zhong

Masters Theses

“Major advancement in Civil Engineering cannot be accomplished without the help of sensors. Among different types of sensors, fiber-optic sensor is known for its light weight, high accuracy, resolution, immunity to electromagnetic interference, and resistance to harsh environment. This research mainly focuses on fiber-optic sensor application on concrete structures as temperature sensor. Thermal Integrity Profiling (TIP) is a non-destructive integrity testing method which makes use of the hydration heat from the concrete curing process to detect defects within a drilled shaft. Any defect of concrete could result in a temperature anomaly in a drilled shaft. The accuracy of the current …

Development Of Amine-Functionalized Mesoporous Alumina For Radioiodine Removal From Water, Mansour Mohammed Alsalbokh

Masters Theses

“Radioactive materials have spread due to careless disposal and nuclear disasters. Some radionuclides can exist in an aqueous media, like radioactive iodine. As a result, in this work amine-functionalized mesoporous alumina was developed to adsorb radioactive iodine from the liquid phase. Bismuth was incorporated, using a wet impregnation method, to test it as a possible silver replacement. Amine grafting was used to functionalize the surface of the mesoporous alumina. All materials prepared in this work were characterized by N₂ physisorption, FTIR and TGA to determine the textural properties, surface functionality, and amine loading. The synthesized materials were tested for …

3d Printing Reinforced Concrete Structures, Bryce Tyler Tafolla

Masters Theses

"This study aims to investigate a 3D printing method to directly incorporate continuous reinforcement into concrete structures. The ability to design and produce complex structures with optimized topographical configuration can be used to reduce potential material waste while maintaining the required structural strength. Furthermore, the ability to actively incorporate reinforcement into printed members substantially reduces potential labor requirements and eliminates the need to set up formwork.

The study began its initial approach with a manual extrusion process containing reinforcement to observe the necessary constraints required to achieve a printing system with this functionality. The second stage of development was designing …

Behavior Of Prestressed Concrete Bridges With Closure Pour Connections And Diaphragms, Gercelino Ramos

Masters Theses

Accelerated Bridge Construction (ABC) has gained substantial popularity in new bridge construction and bridge deck replacement because it offers innovative construction techniques that result in time and cost savings when compared to traditional bridge construction practice. One technology commonly implemented in ABC to effectively execute its projects is the use of prefabricated bridge components (precast/prestressed bridge components). Precast/prestressed bridge components are fabricated offsite or near the site and then connected on-site using small volume closure pour connections. Diaphragms are also commonly used to strengthen the connection between certain prefabricated components used in ABC, such as beam elements. Bridges containing closure …

The Promise Of Vr Headsets: Validation Of A Virtual Reality Headset-Based Driving Simulator For Measuring Drivers’ Hazard Anticipation Performance, Ganesh Pai Mangalore

Masters Theses

The objective of the current study is to evaluate the use of virtual reality (VR) headsets to measure driving performance. This is desirable because they are several orders of magnitude less expensive and, if validated, could greatly extend the powers of simulation. Out of several possible measures of performance that could be considered for evaluating VR headsets, the current study specifically examines drivers’ latent hazard anticipation behavior both because it has been linked to crashes and because it has been shown to be significantly poorer in young drivers compared to their experienced counterparts in traditional driving simulators and in open …

Sustainable Travel Incentives Optimization In Multimodal Networks, Hossein Ghafourian

Masters Theses

Tripod, an integrated bi-level transportation management system, is a smartphone application from the potential user’s point of view which would be instantly accessed prior to performing the trip. Since there are constantly several alternatives for any trip, Tripod considers a series and combination of various parameters, including departure time, mode and route, and rewards for each alternative with a number of redeemable points for goods and services called “Tokens”. The framework responsible for computing the optimized number of tokens awarded to the set of available alternatives in order to minimize the system-wide energy consumption under a constrained Token budget, is …

Modeling The Effect Of New Commuter Bus Service On Demand And The Impact On Ghg Emissions: Application To Greater Boston, Christopher Lyman

Masters Theses

The transportation sector is considered one of the major contributors to greenhouse gas (GHG) emissions in metropolitan areas, and any efforts to reduce these emissions requires strategic management of multiple transportation modes. This paper presents a method to identify opportunities to reduce GHG emissions by expanding commuter bus services and incentives to shift commuters from private cars to transit. The approach uses a nested multinomial logit model for mode choice in a region that includes driving alone, carpooling, walking, cycling, and using four possible transit modes (ferry, commuter rail, rapid transit and bus) by walk access or driving access. A …

Analysis Of Adhesive Anchorage Systems Under Extreme In-Service Temperature Conditions, Rachel Wang

Masters Theses

Adhesive anchorage systems have found widespread use in structural applications, including bridge widening, concrete repair and rehabilitation, and barrier retrofitting. Because these applications typically require adhesive anchorage systems to be installed outdoors, the effects of climate conditions and day-to-day temperature fluctuations on adhesive behavior and performance should be considered. The purpose of this thesis is to simulate pullout tests of adhesive anchorage systems for threaded rod and reinforcing bars and to emulate effects under various temperature conditions through the use of finite element analysis. Results from the finite element simulation are then compared to the physical tests conducted at UMass …

Performance Of Concrete Tunnel Systems Subject To Fault Displacement, Michael Morano

Masters Theses

A Finite Element Analysis (FEA) investigation of concrete tunnel systems traversing seismic faults is carried out to determine how to effectively mitigate the stresses induced in the liner when subject to fault displacement. A parametric study of various fault parameters, both in the damage zone and competent rock, is carried out to determine the site conditions which induce the most stress on the tunnel liner system. Results indicate that friction angle, cohesion, and elastic modulus of fault zones have varying effects on the stresses induced on the liner. The width of damage zone and expected displacements are also investigated and …

High Fidelity Modeling Of Cold-Formed Steel Single Lap Shear Screw Fastened Connections, Rita Kalo

Masters Theses

Cold-formed steel connections are commonly fastened using self-tapping self-drilling screws. The behavior of these connections can differ based on the screw manufacturer or the cold-formed steel product used, both of which have a large selection available for use in industry. Because of their popularity and the many possible variations of these connections, researchers have frequently tested screw connections to characterize their behavior. However, repeatedly conducting this type of experiment is time consuming and expensive. Therefore, the purpose of this work was to create finite element models that can successfully predict the behavior of single lap shear screw connections, a common …

Performance Of One-Part And Two-Part Class C Fly Ash-Based Alkali Activated Mortars, Cedric Chani Kashosi

Masters Theses

“Seeking an eco-friendly concrete, researchers have conducted studies to fully replace ordinary Portland cement (OPC) with fly ash (FA) producing alkali-activated concrete (AAC). Results showed better performance of AAC in terms of high early compressive strength, and durability compared to conventional concrete. However, much is still unknown about the behavior of AAC. From the type of materials used, the curing procedure, and long-term strength development of these binders; a thorough investigation is needed in order to fill the existing gap from previous studies and thus make a step forward to the safely use of AAC in the construction industry. The …