Engineering Commons^™

A Methodological Framework To Evaluate Community Perceptions Of Economic And Safety Impacts Attributed To Highway Bypass And Widening Projects, Karla Diaz-Corro

Graduate Theses and Dissertations

Transportation practitioners have proposed the construction of highway bypass and widening projects in rural communities to address traffic-related problems that include noise pollution and congestion, among others. In the past, the construction of bypass projects has led community residents to raise concerns about potential decreases in business activity for businesses located along the bypassed road. For transportation organizations, it is essential to understand the economic, social, and safety impacts of transportation projects in terms of public perceptions as public input is a required part of the project planning phase. Moreover, it is recommended that agencies perform retrospective analyses of project …

Moisture Monitoring Of A Clt Structure In A Southern Climate, Elizabeth Poblete

Graduate Theses and Dissertations

Understanding of moisture behavior in cross laminated timber (CLT) is critical to the widespread use of CLT in construction in the United States. Currently, very little data exists on the long-term impact of moisture on CLT. The objective of this research is to collect data regarding the long-term moisture variation in the CLT panel at the University of Arkansas Adohi Hall residence hall. The climate of Northwest Arkansas is different from previously monitored buildings, as they were in the Pacific Northwest. Comparatively, Northwest Arkansas has a warmer climate with higher average annual precipitation. Waterproofing efforts are usually employed to prevent …

Cement Stabilized Crushed Stone Base Course Strength And Stiffness Analysis, Andrew Deschenes

Graduate Theses and Dissertations

Approximately 70 – 80% of state departments of transportations (DOTs) utilize the 1993 AASTHO Guide for Design of Pavement Structures (1993 AASHTO) [1] for structural design of pavements. A growing portion of DOT’s are beginning to implement the Mechanistic-Empirical Pavement Design Guide (MEPDG), referred to as AASHTOWare Pavement ME [2]. The 1993 AASHTO flexible guide applies empirically derived unitless strength values referred to as structural layer coefficients and structural numbers (SN) to pavement thickness and pavement types. The 1993 AASHTO rigid flexible guide utilizes the depth and strength of the concrete pavement, with the composite spring constant (kc), which is …

An Investigation Into The Effects Of Fly Ash On Freeze-Thaw Durability Prediction, Yancy Schrader

Graduate Theses and Dissertations

Air is purposefully entrained into concrete primarily to improve resistance to freeze-thaw deterioration while saturated with water. Air entraining admixtures (AEAs) are chemical admixtures designed to entrain air into the concrete to provide adequate resistance to the effects of freezing and thawing. One of the challenges associated with air entrainment in concrete is the interaction of an AEA with supplementary cementitious materials present in the concrete, particularly fly ash. Fly ash is a by-product of the coal fired electrical generation industry, and often contains residual unburned carbon and other components that can increase the AEA demand of a particular concrete …

Effect Of Citric Acid On Slump, Compressive Strength, And Setting Time Of Belitic Calcium Sulfoaluminate Concrete, Israel Aguilar Rosero

Graduate Theses and Dissertations

Belitic calcium sulfoaluminate (BCSA) cement has well established advantages related to fast setting time, fast strength gain, long-term strengths, shrinkage, and sustainability. Due to its fast setting and hardening, this type of cement has historically been used to repair concrete structures, highways, and runways. This work provides much needed guidance on establishing mix design criteria for BCSA cement. Guidance is also given on the effects of set retarders on strength, slump, and setting times. Citric acid and a phosphonic acid-based admixture were tested as retarders for different concrete mixtures. Three studies were performed. In the slump study five different water …

Using Bcsa Cement To Repair Waterway Transportation Structures, Anazaria Johanis Ortega Gonzalez

Graduate Theses and Dissertations

Many maritime structures (e.g., locks, dams, ports) in the US are either reaching or are past their design lives, and there are limited funds for the necessary maintenance activities which can lead to repairs that requires closures. These structures are not easy to detour and often require dewatering before repairs can be made, closures can cause delays and business-related losses which can have a large effect on the nation’s economy. Thus, it is advantageous to reduce the repair time for maritime structures. BCSA (belitic calcium sulfoaluminate) cement is a promising material to perform this type of repair due to its …

Seismic Loading Effects Within Orthogonally Connected Steel Lateral Force Resisting Systems, Alhussin Faraj Aliwan

Graduate Theses and Dissertations

Steel buildings located within seismically active regions require special design considerations to ensure public safety and prevent collapse during an extreme seismic event. Two commonly used steel systems are special moment frames (SMFs) and buckling-restrained braced frames (BRBFs). When two seismic systems share a common column in an orthogonal configuration (such as at a building corner), design specifications currently consider a 100+30 rule wherein the shared column is designed for 100% fuse demand in one direction, plus 30% fuse demand from the other direction. While this rule has been shown to be reasonable for elastic building response, a few studies …

Leveraging Biomimicry And Additive Manufacturing To Improve Load Transfer In Brittle Materials, Ana Paula Bernardo

Graduate Theses and Dissertations

With the emergence of Additive Manufacturing (i.e., 3D printing) in construction, new strategically designed shapes can be created to improve load transfer through structural members and foundations. Cross-sections can be optimized to carry load using less material, or even using weaker constituent materials, like soils, which are cheap and abundant. The goal of this research is to investigate the benefits of using cellular patterns which leverage biomimicry in civil engineering applications, since nature has perfectly engineered materials and patterns which carry loads with the least amount of material possible. Most of the periodic cellular work to date has focused on …

Sustainability In Construction: Using Lean Management Principles To Reduce Waste, Matthew Waite

Theses and Dissertations

The construction industry is facing many challenges. There are growing consumer demands for sustainable building. The construction industry generates a significant portion of the waste going into landfills. The construction industry has failed to keep pace with productivity in the manufacturing industry. Through adoption of Lean management principles, the construction industry can become more sustainable while increasing productivity. The literature was evaluated for three concepts: Lean management principles interaction with sustainability, the current state of sustainability in the construction industry, and the current state of Lean management principles in the construction industry. Lean management philosophies interactions with sustainability has been …

Investigating The Compactability Of Hot Mix Asphalt Utilizing The Concept Of The Locking Point, Pawel Andrzej Polaczyk

Doctoral Dissertations

Compaction is an important process for the asphalt mixture service life. An adequately compacted mixture is crucial for long-lasting pavement. Compaction is a procedure utilized to compress and decrease the volume of the material, which provides essential ingredients that influence the pavement's performance. During asphalt mix compaction, the aggregate coated with asphalt binder are compressed together, following an increase of interparticle friction and surface contact and finally interlocking to provide the resistance to deformation. At the same time, the permeability is decreased, and the durability is increased. Compactability is utilized to evaluate how much compaction energy is required to compact …

A One‐Dimensional Model For Turbulent Mixing In The Benthic Biolayer Of Stream And Coastal Sediments, Stanley B. Grant, Jesus D. Gomez‐Velez, Marco Ghisalberti, Ian Guymer, Fulvio Boano, Kevin Roche, Judson Harvey

Civil Engineering Faculty Publications and Presentations

In this paper, we develop and validate a rigorous modeling framework, based on Duhamel's Theorem, for the unsteady one‐dimensional vertical transport of a solute across a flat sediment‐water interface (SWI) and through the benthic biolayer of a turbulent stream. The modeling framework is novel in capturing the two‐way coupling between evolving solute concentrations above and below the SWI and in allowing for a depth‐varying diffusivity. Three diffusivity profiles within the sediment (constant, exponentially decaying, and a hybrid model) are evaluated against an extensive set of previously published laboratory measurements of turbulent mass transfer across the SWI. The exponential diffusivity profile …

Seismic Performance Of Chevron-Configured Special Concentrically Braced Frames With Yielding Beams, Hayato Asada, Andrew D. Sen, Tao Li, Jeffrey W. Berman, Dawn E. Lehman, Charles W. Roeder

Civil and Environmental Engineering Faculty Research and Publications

Current seismic design requirements for special concentrically braced frames (SCBFs) in chevron configurations require that the beams supporting the braces be designed to resist the demands resulting from the simultaneous yielding of the tension brace and degraded, post-buckling strength of the compression brace. Recent research, including large-scale experiments and detailed finite-element analyses, has demonstrated that limited beam yielding is not detrimental to chevron braced frame behavior and actually increases the story drift at which the braces fracture. These findings have resulted in new expressions for computing beam demands in chevron SCBFs that reduce the demand in the tension brace to …

Comparison Of Additively Manufactured And Wrought 17-4 Ph Stainless Steels In Ultra Low Cycle Fatigue, Timothy Strasser

Graduate Theses and Dissertations

Additive manufacturing (AM) processes allow for creation of complex geometries that are otherwise impractical to fabricate with traditional subtractive methods. AM technology has potential to improve the optimization of seismic lateral force resisting components which dissipate seismic energy through large plastic strains; however, the ultra low-cycle fatigue performance of AM metals are not yet well understood. Void formation during the AM fabrication process has potential to affect performance. This study compares the performance of heat-treated and non-heat-treated AM and wrought 17-4PH stainless steel in Ultra Low Cycle Fatigue. To understand ULCF performance differences between the AM and wrought specimens, post …

Alternate Novel Thermal Structure Interaction Designs Of Molten Salt Shell Structures At High Temperatures Ranging From 565˚C To 700˚C, Nathan David Tyrrell Loyd

UNLV Theses, Dissertations, Professional Papers, and Capstones

Excess energy from solar power stations and other baseline power production methods canbe stored in molten salts (MS) in the 565°C range, therefore allowing the use of large containers to store energy for up to a week and generate eight hours of electricity or more to be used during peak demand hours, at night, or adverse weather conditions, depending on the container size. Supported by Office of Naval Research (ONR), this research presents a survey of molten salt properties used in solar power storage, as well as the history of molten salt usage for energy storage and production for nuclear …

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 …

Impacts Of Environmental And Hydrologic Factors On Urban Stream Water Quality., Jason Patrik Ingram

Electronic Theses and Dissertations

Urban streams can be impacted by a multitude of hydrologic and environmental factors, making maintaining these water sources difficult. Urbanization can exacerbate these impacts creating new challenges in preserving suitable urban stream water quality. Urbanization is the development of city landscape and suburban living within an otherwise natural region. For this environmental impact study, the effects of city development on urban stream water quality was monitored for Mill Creek in Louisville, Kentucky. To study the effects of urbanization on Mill Creek, this project was completed utilizing the BACI method for comparing impacts. The results of the water quality monitoring were …

Understanding Mesoscopic Chemo-Mechanical Distress And Mitigation Mechanisms Of Concrete Subject To Asr, Md Asif Rahman

Boise State University Theses and Dissertations

Alkali-silica reaction (ASR) is one of the common sources of concrete damage worldwide. The surrounding environment, namely, temperature and humidity greatly influence the alkali-silica reaction induced expansion. Global warming (GW) has caused frequent change in the climate and initiated extreme weather events in recent years. These extreme events anticipate random change in temperature and humidity, and convey potential threats to the concrete infrastructure. Moreover, external loading conditions also affect the service life of concrete. Thus, complex mechanisms of ASR under the impact of seasonal change and global warming require a precise quantitative assessment to guide the durable infrastructure materials design …

Development And Application Of Sustainable Binders Comprising Of Fly Ash And Ground Glass Fibers In Portland Cement And Geopolymer Concrete, Omar Alsanusi Amer

All Dissertations

Since cement production is responsible for a significant share of anthropogenic CO2 emissions, the sustainability of concrete construction has become one of the most targeted research and construction industry goals. Many suggestions have been in use to encourage sustainability of concrete construction; one such approach is to partially replace cement by industrial byproducts. The most known industrial byproduct used in concrete construction worldwide has been fly ash, which is a byproduct of burning coal for power generation.

Fly ash use in concrete has various benefits. It reduces the water demand, reduces plastic shrinkage, reduces permeability, and thus improving the durability …

Evaluation Of Accumulated Strain From Both Cyclic Triaxial And Static Creep Tests On Unbound Pavement Materials, Amir Mohammad Sajjadi

Theses and Dissertations

In this research, the behavior of Limerock (LR) aggregates blended with different reclaimed asphalt pavement (RAP) materials were investigated as an unbound base layer. Various combinations of LR and RAP, including 100%LR, 25%RAP75%LR, 50%RAP50%LR, and 100%RAP, were evaluated. Three main experiments performed on the samples were: static creep, static triaxial test, and cyclic triaxial test. The cyclic triaxial test was performed to measure the resilient modulus (MR) of materials. The results of the static triaxial test for 100% RAP showed that the deviator stress at failure steadily increased by increasing the confining pressure, while the 100% LR showed a maximum …

Salt Transport To Saturated Porous Media Under Unstable Conditions: Experimental, Analytical, And Numerical Studies, Kamal Mamoua

Theses and Dissertations

There are three main transport mechanisms that occur under unstable flow conditions: a) The transport of saltwater from the overlying salt source to the underlying porous media, b) the transport of an equivalent volume of displaced groundwater from the porous media into the source, and c) the transport of the saltwater through the porous media. In many situations; such as, estuaries, salt lakes, and landfills, it may be necessary to determine the rate of saltwater transport from an overlying unstable salt source that has heavier saline water overlying porous media fully saturated by lighter saline water. Studies of unstable density …

Enhanced Traffic Incident Analysis With Advanced Machine Learning Algorithms, Zhenyu Wang

Computational Modeling & Simulation Engineering Theses & Dissertations

Traffic incident analysis is a crucial task in traffic management centers (TMCs) that typically manage many highways with limited staff and resources. An effective automatic incident analysis approach that can report abnormal events timely and accurately will benefit TMCs in optimizing the use of limited incident response and management resources. During the past decades, significant efforts have been made by researchers towards the development of data-driven approaches for incident analysis. Nevertheless, many developed approaches have shown limited success in the field. This is largely attributed to the long detection time (i.e., waiting for overwhelmed upstream detection stations; meanwhile, downstream stations …

Development Of A Design Method For Bonded Concrete Pavement Overlays, Ahmed Alsabbagh

Theses and Dissertations

Several asphalt pavements prematurely reached the end of their design life due to wheel loading has dramatically increased on highways. Therefore, transportation and highways agencies often endeavor to provide high-performance pavement to ensure the longest life with low maintenance required. Although asphalt pavement overlay (APO) can provide a quick and low-cost option for pavements rehabilitation, it frequently exhibits excessive rutting especially at highway pavement subjected to stop-and-go traffic conditions. Hence, concrete pavement overlays (CPO) is one of the alternative options for rehabilitating deteriorated pavements. The ultra-thin white topping (UTW) is one type of concrete overlay types and is considered a …

Improved Virus Isoelectric Point Estimation By Exclusion Of Known And Predicted Genome-Binding Regions, Joe Heffron, Brooke Mayer

Civil and Environmental Engineering Faculty Research and Publications

Knowledge of the isoelectric points (pIs) of viruses is beneficial for predicting virus behavior in environmental transport and physical/chemical treatment applications. However, the empirically measured pIs of many viruses have thus far defied simple explanation, let alone prediction, based on the ionizable amino acid composition of the virus capsid. Here, we suggest an approach for predicting the pI of nonenveloped viruses by excluding capsid regions that stabilize the virus polynucleotide via electrostatic interactions. This method was applied first to viruses with known polynucleotide-binding regions (PBRs) and/or three-dimensional (3D) structures. Then, PBRs were predicted in a group of 32 unique viral …

Hydration, Shrinkage, Cracking, And Mechanical Properties Of Cementitious Materials With Lignocellulosic Biomass Wastes., Aofei Guo

Electronic Theses and Dissertations

The disposal of lignocellulosic biomass wastes imposes a huge economic and environmental burden on this society. Recycling lignocellulosic biomass wastes and applying them to cementitious materials provides a sustainable and value-added way for both agriculture and concrete industries. To comprehensively identify the effect of lignocellulosic biomass wastes at different scales on cementitious materials, the hydration, shrinkage, cracking, and mechanical properties of cementitious materials with lignocellulosic biomass wastes were studied. Given the three different forms (powders, chips, and fibers) of lignocellulosic biomass wastes in this study, the research was implemented in three stages. In the first stage, hemp powders were collected …

Concentration And Treatment Of Odors Generated By Landfills, Gabriel Cohen

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Landfills produce hydrogen sulfide (H₂S), an odorous compound that can be a nuisance and danger to public. Biological treatment, in particular bio-trickling filters, is a method for controlling H₂S emissions but startup costs can be costly. The goal of this study is to provide a low-cost method for improving environmental air quality in Nebraska through an odor control device. This study determined that the Loup Central Landfill located near Elba, NE would be an adequate site for the testing and implementation of the odor control device. The off-gas of the Loup Central Landfill was tested for …

Impact Of Disadvantaged Business Enterprises Participation And Mobilization Cost On Highway Project Performance, Shristy Maharjan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Construction practitioners have their goals to complete projects within time without exceeding the allocated budget. However, studies have shown many projects overrun their allocated budget and face delays due to numerous reasons. Some of the main reasons are lack of efficient construction and financial resource management, lack of proper planning, and unavailability of new construction technologies, as well as ineffective supervision and communication, design changes, and unskilled workers. In some studies, mobilization costs, along with the participation of Disadvantaged Business Enterprises (DBEs) in projects were identified as factors affecting the cost and schedule performance of construction projects. However, no statistical …

Designing Next-Generation Transportation Systems With Emerging Vehicle Technologies, Zhiwei Chen

USF Tampa Graduate Theses and Dissertations

Recent advances in computing and artificial intelligence have enabled the development of various emerging vehicle technologies, e.g., autonomous vehicles (AV) and modular autonomous vehicles (MAV). These technologies bring new scientific and engineering problems challenging transportation researchers and practitioners. This dissertation aims to develop a suite of scalable computational and analytical tools for designing and analyzing next-generation transportation systems with the MAV technologies. Also, we intend to empirically study the system impacts in terms of the quality of service, energy implications, and inequality impacts.

For MAV system design, we develop a methodological framework centering at theoretical properties of the optimal system …

Machine Learning Prediction Of Shear Capacity Of Steel Fiber Reinforced Concrete, Wassim Ben Chaabene

Electronic Thesis and Dissertation Repository

The use of steel fibers for concrete reinforcement has been growing in recent years owing to the improved shear strength and post-cracking toughness imparted by fiber inclusion. Yet, there is still lack of design provisions for steel fiber-reinforced concrete (SFRC) in building codes. This is mainly due to the complex shear transfer mechanism in SFRC. Existing empirical equations for SFRC shear strength have been developed with relatively limited data examples, making their accuracy restricted to specific ranges. To overcome this drawback, the present study suggests novel machine learning models based on artificial neural network (ANN) and genetic programming (GP) to …

Use Of Carbon Fiber Reinforced Polymer (Cfrp) Including Sheets, Rods, And Ropes In Strengthening And Repairing Long Reinforced Concrete Columns, Yasir Matloob Saeed

Dissertations and Theses

The use of FRP materials in strengthening and repairing of reinforced concrete (RC) structures has increased in the past two decades. Recently, FRP materials have become one of the most used materials in rehabilitation engineering. For seismic retrofitting of RC structures, usually the process involves strengthening or repairing the vertical support elements of the buildings or bridges. Several studies focused on the use of FRP materials in strengthening and repairing RC columns. Externally bonded (EB) FRP sheets or laminates and near-surface-mounted (NSM) FRP rods have been used for enhancing the strength and ductility of RC columns. Although glass FRP (GFRP) …

Investigation Of The Hall-Petch Relationship Using Strain Gradient Plasticity Model For Finite Deformation Framework, Yooseob Song

Civil Engineering Faculty Publications and Presentations

The Hall-Petch relationship in metals is investigated using the strain gradient plasticity theory within the finite deformation framework. For this purpose, the thermodynamically consistent constitutive formulation for the coupled thermomechanical gradient-enhanced plasticity model is developed. The corresponding finite element method is performed to investigate the characteristics of the Hall-Petch relationship in metals. The proposed model is established based on an extra Helmholtz-type partial differential equation, and the nonlocal quantity is calculated in a coupled method based on the equilibrium conditions. An excellent agreement between the simulation results and the test data is resulted in the Hall-Petch graph. Furthermore, it is …