Civil Engineering Commons^™

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 …

Behavior Of Concrete Structures Reinforced With High Strength Steel, Rahman S. Kareem

Graduate Theses and Dissertations

The structural strength and corrosion resistance of concrete members are improved when A1035 steel is used as the main reinforcement. The enhancement of A1035 is achieved by the modification of the composition and microstructure of the steel. Therefore, the behavior of concrete structures reinforced with high-performance steel (A1035) is different from those reinforced with the regular steel (A615). Concrete bridge decks reinforced with different amounts of A1035 were studied in this research program. The structural behavior of twelve concrete bridge decks reinforced with A615 Grade 420 (60 ksi) and A1035 Grade 830 (120 ksi) steel was investigated at both service …

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 …

Laboratory Study Of Hydrodynamics Of Submerged Bridges, Max Thomson Dean

Civil Engineering Theses - Archive

Bridges are designed to withstand flood and debris loads; however, it is reported that 53% of bridge failures in the U.S. are caused by hydraulic events, including floods, scour, debris, and drifts. A series of scale flume experiments were conducted to determine flood force effects on bridge superstructures. 1:50 scale models of the Texas Department of Transportation’s typical reinforced concrete bridge superstructures were tested. The bridge superstructures included beams (TX28 and TX54 girders, slab beams, and box beams) and an accompanying bridge deck and railing. The drag and lift forces and overturning moments were measured by load sensors for various …

Developing Strength Reduction Factor For Flexural Design Of Reinforced Concrete Beams Exposed To Fire, Sahar Aradmehr

Civil Engineering Theses - Archive

Fire is a common hazard that may happen during the lifetime of concrete structures. Thus, it is one of the loads considered in building and tunnel design standards and codes. Dependency of the safety and structural integrity of a building to load-bearing elements such as beams requires the safe design of these elements. Flexural design of reinforced concrete (RC) beams under fire is critical. Typical load and resistance factor design (LRFD) of flexural member at ambient temperature deals with comparing the factored applied load with its capacity. Strength reduction factors are applied to the calculated nominal moment capacity to take …

Laboratory Tests And Numerical Model Of Geothermally Heated Bridge Deck With Attached Hydronic Loop, Teng Li

Civil Engineering Dissertations - Archive

An accumulation of ice and snow on pavement slabs and bridge decks always adversely impacts driving conditions and results in motorist accidents. The use of the more popular deicing methods, including plowing, salting, and sanding, is limited by their relatively high cost for materials, fuel, maintenance, and labor. Geothermal energy, which is considered a renewable, sustainable, clean (i.e., zero carbon emission), and directly used energy source, has been successfully applied to bridges and pavements for deicing. However, existing geothermal bridge and pavement deicing designs are primarily employed for new bridges where hydronic loops, which are considered internal heating, are embedded …

Experimental Investigation Of Anchor Group Effects On Concrete Breakout Strength Within Fiber Reinforced Concrete, Atheer Alaa Al Khafaji

Civil Engineering Theses - Archive

This research investigates the effect of anchor groups on concrete breakout strength within steel fiber reinforced concrete (SFRC) under tension load. High strength steel headed studs (F1554 Grade 105) in grouping action were cast-in-place within concrete specimens of different amounts of steel fibers. Four types of concrete mix designs were produced in the lab by using different amounts of steel fibers (0%, 0.5%, 1%, and 1.5%) by volume fraction of the mixture. The physical properties of steel fibers reinforced concrete were calculated through testing of specimens at the Civil Engineering Laboratory Building (CELB). In total, 12 cylinder specimens of 4-inch …

Hydrologic & Hydraulic Analyses To Re-Establish Trigg Branch’S Jurisdictional Channel To Pre-Dam Condition Using Hec-Hms & Hec-Ras Models, Razak Ahmed Albarqaawee

Civil Engineering Theses - Archive

Birds strikes are the most prevalent cause of airplanes strikes, and retention ponds near airports are one of the most attractive spots for both immigrant and domestic wildlife USDA (2017). Since the Trigg Lake, water surface area covers around 46 acres and is located approx. 1.5 miles from four main runways, which make the lake a perfect shelter for birds to build their nests and eventually strike departing and/or landing aircraft. Based on a Federal Aviation Administration (FAA) advisory circular, no retention pond should be constructed within five miles of an airport nor should it have standing storm runoff for …

Development Of Deterioration Models For Street Pavement In Dallas-Fort Worth Metroplex, Mladjan John Grujicic

Civil Engineering Dissertations - Archive

Accurate prediction of pavement deterioration is vital for an efficient and cost-effective allocation of available budgets for keeping an agency’s road networks operating at a desirable level. Currently, most cities in the Dallas-Fort Worth Metroplex area are using the software PAVERTM and the associated performance models to predict future conditions as they do not have available reliable prediction models. However, the problem with this type of modeling is that the models are not calibrated to local conditions. The Pavement Deterioration Prediction models that have been developed in this research will help any pavement management agencies within DFW Metroplex area to …

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 …

Use Of Time-Domain Reflectometry To Characterize Thermal And Hydraulic Properties Of Unsaturated Sands, Xuelin Wang

Civil Engineering Dissertations - Archive

Unsaturated soil is an essential consideration for many geotechnical engineering fields, for example, soil bearing capacity, soil lateral earth pressure, slope stability analysis, and seepage-related problems. Thermal-hydro-mechanical (THM) processes govern the behavior of unsaturated soils. Therefore, it is critical to simultaneously measure soil moisture, density, and thermal properties to better study THM processes. A thermo-time-domain reflectometry (thermo-TDR) sensor, a dual-probe for both soil moisture and thermal properties, is improved (based on its previous design) and fully calibrated through various soils at different soil moisture circumstances. Nine different chemical reagents with known dielectric constant were utilized to perform calibration of the …

Evaluation Of The Use Of Anchorage Systems For Strengthening Concrete Members Reinforced By Fiber-Reinforced-Polymer (Frp) Laminate, Mai Abd Alrhman Alrhman Aljaberi

Civil Engineering Dissertations - Archive

An anchorage system is the most effective method for preventing or delaying the debonding of fiber-reinforced polymer laminates; however, despite extensive studies, the related design information is still unclear and limits its use. The goal of this research, therefore, is to investigate the parameters that affect the debonding strain of CFRP beams secured with different types of anchors. For this purpose, 34 small-scale beams were tested under four-point loading. Two (2) of them were control beams (no FRP, no anchors), 8 were strengthened with FRP at their tension sides, and the remaining 24 were secured with different types of anchor …

Improving Flood Forecasting Using Conditional Bias-Aware Assimilation Of Streamflow Observations And Dynamic Assessment Of Flow-Dependent Information Content, Haojing Shen

Civil Engineering Dissertations - Archive

Accurate forecasting of floods is a long-standing challenge in hydrology and water management. Data assimilation (DA) is a popular technique used to improve forecast accuracy by updating the model states in real time using the uncertainty-quantified actual and model-simulated observations. A particular challenge in DA concerns the ability to improve the prediction of hydrologic extremes, such as floods, which have particularly large impacts on society. Almost all DA methods used today are based on least squares minimization. As such, they are subject to conditional bias (CB) in the presence of observational uncertainties which often leads to under- and over-prediction of …

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 …

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

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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

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 …