Civil Engineering Commons^™

Mechanics And Physical Attributes Of Nature-Based Alterations: Rock Reinforcement And Urban Heat Island Assessment, Mary Chikondi Ngoma

Dissertations

Ground improvement is critical to geotechnical and geo-engineering systems, where modification of the properties of geomaterials (rocks and soils) is required to maintain stability and prevent failure of infrastructure installed within and around them. This need has become increasingly important with rapid urbanization and population growth, which intensify demands on surface and subsurface systems and further challenge the performance of supporting geomaterials. As a result, there is growing interest in nature-based solutions, particularly biologically mediated processes such as biocementation, which can enhance the physical, hydraulic, and mechanical properties of geomaterials while offering environmentally sustainable alternatives to conventional ground improvement techniques. …

Remote Vibration Based Monitoring Of Bridge Scour, Alan Kazemian

Dissertations

The gradual erosion of the sediment around a bridge foundation is called Scour. This erosion is caused by water flow and increases during times of high-water flow such as flooding. The scour leaves the bridges structurally unsound over time and jeopardizes the safety of the structure. Approximately 60 percent of bridge failures in the United States are caused by scour. A variety of types of devices have been used to detect scour. Most of these devices only observe the scour and not the structural integrity of the bridge. The typical approach has relied on visual inspections of the bridges after …

Sustainable And Cost-Effective Work Zone Scheduling On Two-Lane Highways With Managed Lanes, Ahmed Z. Edrees

Dissertations

Roadway maintenance projects greatly influence the roadway capacity, resulting in potential traffic disturbances captured by delays. Additionally, costs associated with these projects tend to be exorbitantly extensive. Most agencies and planners try to find a solution that minimizes roadway maintenance costs, traffic delays, crash risks, and environmental impact.

Work zones on two-way two-lane roadway typically avoids high-demand periods. Lane-closure scenario is commonly used and converts the open lane into a phantom intersection, alternating two-direction movements on one lane with the help of a flagger or a temporary signal. Alternatively, using shoulders as temporarily managed lanes allows for simultaneous two-way movements …

A Molecular Dynamics Study On The Destruction Mechanism Of Per And Polyfluoroalkyl Substances Due To Ultrasound Technology, Bruno Bezerra De Souza

Dissertations

Per- and polyfluoroalkyl substances (PFAS) are a group of stable synthetic chemicals that are highly persistent and harmful pollutants to the environment and human health. PFAS have caused a strong public and regulatory response due to their ubiquitous presence in the environment and toxicity to humans. The application of ultrasound is one of the most effective treatment technologies for the mineralization of PFAS in contaminated water. However, this technology is treated as a black box causing the inability to be optimized. Therefore, there is a pressing need to investigate the intricate dynamics of PFAS degradation under ultrasound to unlock its …

Microplastic Abundance And Removal In Stormwater Using Green Infrastructure, Meghana Parameswarappa Jayalakshmamma

Dissertations

Microplastics (MPs) are increasingly recognized as a pervasive environmental contaminant, conveying other contaminants, accumulating in aquatic organisms, and posing ecological risks. The existing research has primarily focused on MPs in wastewater treatment plant effluents in surface waters. However, the role of stormwater systems in MP transport has been less explored. Given the rise in MPs from urban sources, stormwater runoff from urban areas may serve as a critical conduit for transporting land-based MPs into aquatic environments. Green infrastructures (GIs) have been recognized for mitigating flooding and improving water quality from minor storms by trapping stormwater pollutants. Yet, the capability of …

Development And Validation Of Simulation Protocols For Assessing Stresses In A Network Tied Arch With A Posttensioned Tie Girder, Kanchani Lakamalika Kumari Basnayake Mudiyanselage

Dissertations

Posttensioned concrete members; especially the posttensioned tie girders, are critical load resisting elements in network tied arch bridges. The stresses in the structure are influenced by the prestress losses that depend on the posttension force magnitude, time-dependent concrete modulus of elasticity, and concrete creep and shrinkage. The use of performance-based, high-strength, ternary mixes to promote the carbon neutral concrete and the need for executing multiple construction stages challenge the assessment of the state of stress in a completed bridge. The primary objective of this study is the development and validation of simulation protocols for assessing stresses in a network tied …

Multi-Physics Numerical Simulation Of Corrosion And Service Life Evaluation Of Novel Reinforced Concrete Systems, Jin Fan

Dissertations

Durability challenges of reinforced concrete materials can shorten the service life and increase the carbon footprint of civil infrastructure systems. Novel alternative materials, such as high-performance fiber reinforced cementitious composites (HPFRCCs) and recycled aggregate concrete (RAC), offer an alternative to tradi-tional concrete materials by increasing the service life of infrastructure or reducing raw material consumption, thereby reducing the life-cycle carbon footprint. Due, in part, to a lack of robust numerical tools, predicting the durability response of these emerging cementitious materials has been insufficiently addressed. A time-dependent multi-physics modeling framework is proposed and adopted to investigate the chloride induced deterioration mechanisms …

Upgrading The Performance Of Steel Beams Using Fastened Advanced Composite Materials, Omnia Ragab Abouelhamd

Dissertations

Bonding Fiber-Reinforced Polymers (FRP) is commonly used to enhance the structural performance of existing steel beams; however, the brittle failure at the adhesive risks the effectiveness of the bonded system. Fastening FRP is recently proposed to avoid the brittle failure of the adhesive. Promising outcomes of few studies on fastened FRPsteel system provoked the interest to investigate the effects of various fastening parameters on the performance of fastened FRP-steel beams.

This study investigates, experimentally and numerically, the impact of various fastening parameters on the performance of fastened FRP-steel beams. The proposed method involves fastening carbon-glass hybrid FRP (HFRP) strips to …

Performance Of Cement-Free Geopolymer Composites Made With Locally Available Industrial Solid Waste Materials, Omar Fawwaz Abbas

Dissertations

This dissertation is concerned with developing sustainable cement-free mortars made with local industrial by-product materials. Ladle slag is generated in mass quantities from secondary steel treatment in the United Arab Emirates (UAE). It is typically disposed of in stockpiles and landfills. Ladle slag is an excellent candidate for geopolymer composites because of its aluminosilicate composition. Such composites are developed by activating industrial by-products in alkaline solutions. This project aims to utilize locally produced ladle slag from the secondary steel treatment in the UAE to produce geopolymer mortars. The effect of various mixture proportions on the developed composites was assessed using …

Effect Of Fluid Penetration On The Damage Processes And Microseismicity Due To The Hydraulic Fracturing Of Rocks, Catarina Baptista-Pereira

Dissertations

The hydraulic fracturing is used when fluids are injected inside the matrices of rocks to allow the creation of new cracks while, the propagation of the existent cracks can also occur. This process has been widely used for the past decades in the deep earth energy sector which comprises four main subsectors: 1) recovery of geothermal resources, 2) CO₂ and hydrogen sequestration; 3) wastewater and nuclear waste disposal, and 4) recovery of (non)conventional fluids. By creating new flow paths or enhancing the existing ones, the pores are allowed to connect and, thus, it increases the permeability of rocks. For …

Investigating Pedestrian Distraction By Phone At Intersection Crossings, Safety Implications And Potential Treatments, Lusanni Mercedes Acosta Rodriguez

Dissertations

Road user distraction is a major safety concern. The issue is not only for drivers, but also for vulnerable road users such as pedestrians. Every year people are involved in potential and real crashes due to being distracted while walking/crossing streets. Although there are several ways by which pedestrians are distracted, phone use while crossing streets is among the riskier and growing behaviors. Crossing an intersection, especially those with heavy traffic, requires full attention from the individual. Inattentiveness to traffic while on a phone call, texting, web-surfing, listening to music before crossing a street can lead to a fatal crash. …

The Impact Of Material And Environmental Properties On The Ettringite - Metaettringite Thermochemical Reaction, Aaron Strand

Dissertations

The use of energy is an essential need for people, with demand constantly increasing due to an increasing population and an increase in living and comfort standards. Since 1965, world energy consumption has quadrupled. During peak utilization, the strain on the grid infrastructure can be immense. As energy demand fluctuates during different times of the day and year, the energy production needs to scale accordingly This creates inefficiencies within the system such as over building generation capacity or losses from start up or ramping up production. This can be alleviated through load leveling where excess energy generated during low demand …

Behavior Of Steel Fiber Reinforced Concrete Made With Recycled Concrete Aggregates: Material Characterization And Deep Beam Shear Response, Nancy Kachouh

Dissertations

This research aims to examine the performance of concrete made with recycled concrete aggregates (RCAs) and steel fibers. It comprises material characterization tests, large-scale reinforced concrete (RC) deep beam tests, and numerical modeling. Material characterization test parameters included the RCA replacement percentage (30, 70, and 100%) and the steel fiber volume fraction (vf = 1, 2, and 3%). Fourteen large-scale deep beam numerical models with and without web openings made with 100% RCAs and steel fibers were developed and validated through a comparative analysis with test results. A numerical parametric study was conducted to investigate the effect of varying …

Connected And Automated Vehicles: Their Implication On Capacity Of A Basic Freeway Section And Impacts On Walkway Safety, Sia Macmillan Lyimo

Dissertations

Autonomous vehicles have recently gained the attention of researchers due to their expected potential benefits on highway traffic streams, such as improving roadway capacity, among others. It is imperative to investigate how these expected benefits can be leveraged in the transportation sector. Understanding the safety and operational benefits helps the concerned transportation agencies and other key stakeholders to make necessary infrastructural and policy adjustments to accommodate such future traffic operation changes. The main goal of this dissertation is to study the impact of connected and automated vehicles on freeway capacity. The simulated environment was created to emulate autonomous vehicle behaviors, …

Shale Softening Based On Pore Network And Laboratory Investigations, Di Zhang

Dissertations

This dissertation consists of two major parts: Firstly, experimental investigation of four major shale softening mechanisms and quantifications of structural parameters. Secondly, numerical simulations of nano-scale flow behaviors using the previous experiments determined parameters based on modified pore network modeling.

Hydraulic fracturing is widely applied to economical gas production from shale reservoirs. Still, the gradual swelling of the clay micro/nano-pores due to retained fluid from hydraulic fracturing causes a gradual reduction of gas production. Four different gas-bearing shale samples are investigated to quantify the expected shale swelling due to hydraulic fracturing. These shale samples are subject to heated deionized (DI) …

Performance Evaluation Of Transportation Systems For Sustainability And Smart-Growth Of Cities: An Integrated Assessment Of Health Impacts, Ahmad Feizi

Dissertations

The performance of transportation systems is a significant component that influences the quality of life. The performance evaluation refers to a process of determining how well transportation systems perform regarding their intended goals and objectives. The advancement of information and communication technology and the integration between transportation systems and advanced technologies have directed more attention to the concept of smart cities. Smart cities are constituted of several interrelated components. Therefore, this offers comprehensive and integrated frameworks to evaluate the transportation performance and understanding of multifaceted interactions between the components from a transportation engineering perspective in four sections.

In the first …

Data Mining Of Unstructured Textual Information In Transportation Safety Domain: Exploring Methods, Opportunities And Limitations, Keneth Morgan Kwayu

Dissertations

The unprecedented increase in volume and influx of structured and unstructured data has overwhelmed conventional data management system capabilities in organizing, analyzing, and procuring useful information in a timely fashion. Structured data sources have a pre-defined pattern that makes data preprocessing and information retrieval tasks relatively easy for the current technologies that have been designed to handle structured and repeatable data. Unlike structured data, unstructured data usually exists in an unorganized format that offers no or little insight unless indexed and stored in an organized fashion. The inherent format of unstructured data exacerbates difficulties in data preprocessing and information extraction. …

Safe Yield Comparisons For The 1960’S And 2000’S Drought In The Passaic River Basin, Stephanie R. Santos

Dissertations

The Passaic River Basin is a complex system of rivers, tributaries, reservoirs, and some of the largest water purveyors in the State of New Jersey. Located in the northeastern part of the State, it drains approximately 800 square miles of water that is used for distribution to the five major purveyors: North Jersey District Water Supply Commission, Passaic Valley Water Commission, Jersey City, Newark, and New Jersey American Water. These purveyors operate under a safe yield, which is defined by the New Jersey Department of Environmental Protection (NJDEP) as the amount of water that should be continuously available should the …

The Stability Of Nanobubbles And Its Application In Contaminated Sediment Treatment, Shaini Dilsha Aluthgun Hewage

Dissertations

This dissertation consists of two sections. First, nanobubbles' stability and behavior are studied using experimental and theoretical approaches. Second, nanobubbles application combined with ultrasound to remediate contaminated sediments is discussed.

The stability study consists of four sections. (i). Laboratory investigation to determine bubble size distributions and zeta potentials for different gases, pH levels, temperatures, and salt conditions. (ii). A theoretical study based on the diffused double layer theory to explain nanobubbles' behavior in different NaCl concentrations. (iii). Nanobubbles' stability in electrolyte solutions under different ion valencies using deionized water, NaCl, Na₂SO₄, Na₃PO₄, …

Membrane-Based Removal Of Ammonia From A Waste Stream And Its Recovery, Philip A. Aligwe

Dissertations

At neutral pH levels, ammonia in aqueous streams exists in two forms: ammonium ion (NH₄⁺) and dissolved ammonia gas molecules (NH₃). Membrane separation serves as a viable option for treatment of ammonia containing effluents. This can be achieved via by stripping NH₃ from an ammonia feed solution at feed solution pH > 11 via hollow fiber supported gas membrane (SGM) or removing NH₄⁺ from an ammonia feed solution at feed solution pH < 7 via liquid or polymeric membranes.

The first study reported here examines the influence of feed volumetric flow rates on outlet NH₃ concentrations in parallel flow …

Modeling Strategies For Structures Using Ductile Concrete Materials In Seismic Applications, Hasan Tariq

Dissertations

High-Performance Fiber-Reinforced Cementitious Composites (HPFRCCs) have made striking advances over the last two decades as an alternative material to replace ordinary concrete in regions of high seismic intensities. In contrast to ordinary concrete which has a brittle tensile response, HPFRCCs exhibit tensile strain hardening and multiple crack propagation. The application of HPFRCC in various structural components demonstrate effectiveness by improving damage resistance, deformation capacity, and energy absorption capacity. Despite these benefits, the failure mode of reinforced HPFRCC components is dominated by reinforcement fracture unlike traditional reinforced concrete components which fail in flexure by crushing. The unique behavior of HPFRCC members …

Stress-State And Injection-Rate Dependent Damage Processes During The Hydraulic Fracturing Of Granite, Gayani Sasendrika Gunarathna

Dissertations

Hydraulic fracturing is a well-stimulation technique that is employed in field applications, such as enhanced geothermal systems (EGS) and shale oil/gas extraction. This research experimentally investigates the effect of the state of stress and injection rate on the hydraulic fracturing processes. In addition, a displacement discontinuity method (DDM) code, FROCK, is used to model the crack initiation and propagation in a granite specimen under hydraulic fracturing conditions. In order to conduct the experimental work, a test setup capable of applying a triaxial state of stress and water pressure inside pre-fabricated flaws cut in prismatic granite specimens is developed. Additionally, the …

Numerical And Analytical Methods To Predict Behavior Of Reinforced Ductile Concrete Composites, Mandeep Pokhrel

Dissertations

Structural components constructed with ductile concrete composites, such as high-performance fiber-reinforced cementitious composites (HPFRCC), are known to perform exceptionally well under extreme mechanical and environmental loading conditions compared to traditional concrete. HPFRCC flexural components exhibit enhanced performance in terms of displacement ductility, energy dissipation capacity, and damage tolerance capacity. However, recent research suggests that the flexural behavior of reinforced HPFRCCs in terms of crack progression, reinforcement plasticity, and failure mechanism is significantly different than conventional reinforced concrete. Specifically, the failure mode of flexural members is found to be predominantly through the fracture of longitudinal reinforcement rather than compression crushing of …

The Impact Of Conversion On The Durability Of Calcium Aluminate Cement Concrete Systems, Marwa Mohsen Korayem

Dissertations

The deterioration of infrastructure in North America has resulted in a significant need for concrete repair materials that can be used to maintain service life of these structures. Hydraulic cement based rapid repair materials can be used to repair pavement and bridge deterioration with minimal impact on economic activities such as freight handling or public transportation. While there are many options for use in repair situations, calcium aluminate cements have become more popular recently, particularly in situations where repairs must be completed rapidly.

Calcium aluminate cement (CAC) is a cement characterized by its rapid strength gain, even at low temperatures …

Analyzing Impacts Of Transportation And Non-Transportation Activities On Human Health With An Advanced Platform For Collecting Travel And Physical Activity Data, Raed Abdullah Hasan

Dissertations

Recently much attention is paid to the lack of physical activities that may cause the health problems in many counties. Travel activities provide a certain amount of physical activities, and the active transportation, such as walking and cycling, becomes more important as an essential element of transportation. The active transportation is expected to contribute to improving human health by reducing cardiovascular disease, obesity, and premature death. However, detailed relationship between the transportation choices and human health has not been well understood. Therefore, there is a need for investigating traveler behaviors and how their choices affect physical activities and public health. …

Effects Of Electro-Osmotic Consolidation Of Clays And Its Improvement Using Ion Exchange Membranes, Lucas Martin

Dissertations

Electro-osmosis is an established method of expediting consolidation of soft, saturated clayey soils compared to commonly used methods, such as preloading with wick drains. In electro-osmotic consolidation a direct current (DC) is applied via inserted electrodes. This causes hydrated ions in the interstitial fluid to migrate to oppositely charged electrodes. Because the clay particles have a negative surface charge, the majority of ions in the interstitial fluid are positively charged. Therefore, the net flow will be towards the negatively charged electrode (cathode), where the water can be removed and thus consolidation is achieved. Certain problems, such as pH changes in …

Fatigue Performance Of Rc Beams Strengthened With Near Surface Mounted Cfrp Composites, Tamer Ghaith Mousa Eljufout

Dissertations

Bridges have a fundamental role in improving the effectiveness of highways and providing an expedient and express traffic system. Over time, Reinforced Concrete (RC) bridges degrade due to gradually increased traffic loads and environmental deteriorations. Subsequently, service loads might cause higher stresses in concrete and steel reinforcement than stresses considered in the design stage. This affects the structural performance of RC beams and leads to sudden fatigue failure. As such, there is an essential need for rehabilitation to avoid hazards and tragedies.

Carbon Fiber Reinforced Polymer (CFRP) composites are becoming widely used to strengthen RC bridges. Near Surface Mounted (NSM) …

Assessing Infrastructure Elements Using Automated Object Detection Technique In Smart City Applications, Majid Mastali

Dissertations

Nowadays, road features are becoming more complex leading to more complicated complaints regarding urban environments. Point Cloud Data (PCD) processing is an essential element for detecting objects and analysing human driving behavior to identify the variables defining challenging objects and maneuvers in smart cities. PCDs include a range of processing, including indirect processing (e.g., data converting, cleaning process) and direct process (e.g., pass through elevation filter, statistical outlier removal, normal estimation as well as classification). Static and dynamic object detection and analysis are typically considered the most sophisticated options subsumed under PCDs. They involve direct evaluation of both static and …

Deterioration Prediction Modeling For The Condition Assessment Of Concrete Bridge Decks, Aqeed Moshin Chyad

Dissertations

Bridges are key elements in the US transportation system. There are more than six hundred thousand bridges on the highway system in the United States. Approximately one third of these bridges are in need of maintenance and will cost more than $120 billion to rehabilitate or repair. Several factors affect the performance of bridges over their life spans. Identifying these factors and accurately assessing the condition of bridges are critical in the development of an effective maintenance program. While there are several methods available for condition assessment, selecting the best technique remains a challenge. Therefore, developing an accurate and reliable …

Decontamination Of The Passaic River Sediments Using Ultrasound With Ozone Nano-Bubbles, Janitha Hewa Batagoda

Dissertations

The Passaic River is 129km long and flows through the northern New Jersey. During the mid-twentieth century, the U.S. census indicated that there were approximately 2,900 industries along the river bank. The amount of industries established next to the river indicated the inevitable river pollution, which was compounded by lenient environmental protection laws. One of the major contributors of the river pollution was Diamond Alkali Co., which started production of chemicals around 1951 at the 4km marker in the Passaic River.

In 1970, the United States Environmental Protection Agency (U.S. EPA) identified the Passaic River as the second most polluted …