Civil Engineering Commons^™

Influence Of Different Rubber Modified Binder Variables On Performance Properties Of Porous Asphalt Mixtures, Katelyn Love

All Theses

Porous asphalt is a type of pavement in which surface water can permeate down into the subbase below. Open graded friction course (OGFC) is a type of porous asphalt often used as a surface course on top of dense graded pavements on high speed roadways. Due to an increase in waste tires, rubber modified asphalt has become an increasingly popular material around the world, including the US. The rubber modified asphalt is created by utilizing processed rubber particles blended into the mixture. This research investigated the effects of rubber modified binder on the performance of porous asphalt by evaluating the …

An Ecohydrological Perspective On Drought-Induced Forest Mortality, Anthony J. Parolari, Gabriel Katul, Amilcare Porporato

Civil and Environmental Engineering Faculty Research and Publications

Regional‐scale drought‐induced forest mortality events are projected to become more frequent under future climates due to changes in rainfall patterns. The occurrence of these mortality events is driven by exogenous factors such as frequency and severity of drought and endogenous factors such as tree water and carbon use strategies. To explore the link between these exogenous and endogenous factors underlying forest mortality, a stochastic ecohydrological framework that accounts for random arrival and length of droughts as well as responses of tree water and carbon balance to soil water deficit is proposed. The main dynamics of this system are characterized with …

Numerical Simulation Of Flow In Ozonation Process, Jie Zhang

USF Tampa Graduate Theses and Dissertations

In the last two decades, Computational Fluid Dynamics (CFD) has shown great potential as a powerful and cost-efficient tool to troubleshoot existing disinfection contactors and improve future designs for the water and wastewater treatment utilities.

In the first part of this dissertation two CFD simulation methodologies or strategies for computing turbulent flow are evaluated in terms of the predicted hydraulic performance of contactors. In the LES (large eddy simulation) methodology, the more energetic, larger scales of the turbulence are explicitly computed or resolved by the grid. In the less computationally intensive RANS (Reynolds-averaged Navier-Stokes) methodology, only the mean component of …

The Development Of Empirical Models To Evaluate Energy Use And Energy Cost In Wastewater Collection, David Young

All Dissertations

This research introduces a unique data analysis method and develops empirical models to evaluate energy use and energy cost in wastewater collection systems using operational variables. From these models, several Best Management Processes (BMPs) are identified that should benefit utilities and positively impact the operation of existing infrastructure as well as the design of new infrastructure. Further, the conclusions generated herein display high transferability to certain manufacturing processes. Therefore, it is anticipated that these findings will also benefit pumping applications outside of the water sector. Wastewater treatment is often the single largest expense at the local government level. Not surprisingly, …

Dynamic Excitation Related Uncertainty In Ambient Vibration Testing Of A Truss Bridge, Ryan T. Dufour

Civil Engineering Undergraduate Honors Theses

The aging and deteriorating state of bridges in the US, along with the many limitations of the visual inspection data that is used for assessing and evaluating their condition, have provided motivation for research on experimental methods to quantitatively describe and evaluate their in-situ performance and condition. Ambient vibration testing is one such global characterization approach that has been widely explored due to its low cost and ease of implementation for in-service bridges. The testing is used to identify the modal properties of the structure, typically the natural frequencies, mode shapes, and damping ratios. Although ambient vibration testing has been …

Evaluation Of The Effects Of Dynamic Excitation Characteristics On Ambient Vibration Test Results For A Multi-Girder Bridge, Gibran Santana

Civil Engineering Undergraduate Honors Theses

The bridge population in the US is currently aging and deteriorating rapidly. More than 30% of the bridges across the country have already exceeded their expected design life. Therefore, it is important to develop more timely, reliable and quantitative alternatives to the qualitative visual inspection approach that is currently used to evaluate these structures. One experimental approach that has been researched extensively for quantitatively characterize bridges is Ambient Vibration Testing (AVT) also known as Operational Modal Analysis (OMA). In this approach, the vibration responses of a structure due to unmeasured and uncontrolled ambient dynamic excitation are measured and analyzed to …

Temperature Sensitivity Of Foamed Warm Mix Asphalt, Ryan Michael Hagedorn

Civil Engineering Undergraduate Honors Theses

Foamed warm mix asphalt (WMA) is a technology that is beginning to be utilized across the United States. Often, producers are placing foamed WMA at decreased temperatures without fully understanding the properties of this relatively new product. By studying the volumetric properties of laboratory produced foamed WMA, this study sought to better understand the temperature sensitivity of foamed WMA and the potential factors that contribute to this sensitivity. Two mix designs containing primarily limestone aggregate were tested using differing binder grades. It was determined that binder grade, binder source and potentially the inclusion of recycled asphalt pavement all influence how …

Examination Of Nitrogen To Phosphorus Ratio In Nutrient Removal From Wastewater Through Chlorella Vulgaris, Courtney L. Hill

Civil Engineering Undergraduate Honors Theses

A need for phosphorus removal is becoming increasingly evident as some wastewater treatment plants struggle to meet wastewater effluent nutrient requirements. High nutrient levels in wastewater effluents have also caused ongoing tension between the state of Oklahoma and Arkansas regarding the pollution of the Illinois River. This research seeks to establish the relationship between nitrogen to phosphorus ratio in wastewater and the level of nutrient reduction using Chlorella vulgaris. Seed cultures of Chlorella vulgaris were added into solutions with various ratios of nitrate to phosphate representative of treated domestic wastewater and the removal of nitrogen and phosphorus were measured in …

Shear Capacity Of Prestressed Lightweight Self-Consolidating Concrete, Micah Alan Wyssmann

Civil Engineering Undergraduate Honors Theses

In prestressed members, self-consolidating concrete (SCC) has in some cases exhibited lower shear capacity than conventional concrete, which has been attributed to decreased aggregate interlock. However, little data is currently available to assess whether use of lightweight aggregate in prestressed SCC beams has further impact on aggregate interlock and shear strength. This study measured the shear capacity of six prestressed beams made from three different concrete mixtures: lightweight self-consolidating concrete (LWSCC) with expanded shale aggregate, LWSCC with expanded clay aggregate, and control normal weight SCC with limestone aggregate. Predicted shear capacities were determined based on current ACI Building Code and …

Considerations For Hood Placement And Design Downstream From A Fixed-Cone Valve, Barry Jacob Prettyman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In many hydroelectric projects there is a need to safely dissipate the energy associated with the elevation of the water surface. When the flow is not passing through the turbines, bypass valves are often used. A valve that is commonly used is the fixed-cone valve. Fixed-cone valves, also known as Howell-Bunger valves, are devices often used to safely reduce flow energy at dams with medium to high heads. The valve directs the outflow into a conical hollow jet, which requires a large area for energy dissipation. The flow is controlled by an adjustable sleeve, also known as the gate which …

Causes And Countermeasures For Nappe Oscillation: An Experimental Approach, Aaron Allan Anderson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Weirs are commonly used as spillways to release flows from a reservoir. The freefalling jet on the downstream side of the weir is called the nappe. Under certain hydraulic conditions, determined mainly by the size, design, and construction of the weir, nappe oscillation, otherwise known as nappe vibration, can occur. Characteristics of this dynamic behavior include excessive acoustic energy manifested as sound pressure waves and lowfrequency noise accompanied by horizontal waves or banding on the nappe. Mitigation of this process may be required, especially if the weir operates in close proximity to occupied structures. Instability of water jets moving through …

Numerical Investigation Of One-Dimensional Shallow Water Flow And Sediment Transport Model Using Discontinouous Galerkin Method, Farzam Safarzadeh Maleki

All Dissertations

A one-dimensional shallow water flow and sediment transport model is developed using a discontinuous Galerkin finite element scheme. As a first step, four different time marching schemes as well as three different slope limiters have been investigated to find the optimum modeling combination. The efficiency and accuracy of the time marching schemes and slope limiters are quantitatively examined using CPU runtime and comparison between the simulated results and theoretical/experimental data. It is found that using the second order Adam-Bashforth time marching scheme and Monotonized Central method leads to most efficient and accurate results. As the second part of this research, …

Minimizing Bridge And Pavement Deterioration From Large Trucks: A Policy Analysis For Damage Recovery, Kakan Dey

All Dissertations

Facing an exceptional challenge of maintaining state roadways with ever-shrinking financial resources, this research examined multiple facets of the impact of overweight trucks. The objectives of this research were to investigate the impact of overweight trucks on pavements and bridges, and develop policy recommendations based on technical analysis and the modern political and institutional environment in South Carolina. To achieve the objectives, this research modeled pavement and bridge deterioration, investigated the adequacy of standard practices in state agencies, examined how trucking industry perceives those practices, and developed policy analysis models. Pavement and bridge deterioration analysis revealed that pavement and bridge …

An Assessment Of The Emas Pump And Its Potential For Use In Household Water Systems In Uganda, Jacob Daniel Carpenter

USF Tampa Graduate Theses and Dissertations

Rural improved water supply coverage in Uganda has stagnated around 64% for a number of years and at this point more than 10 million rural people do not have access to an improved drinking water source. It has been recognized that progress toward improved water supply coverage and increased service levels may be gained through Government and nongovernmental organization (NGO) support of private investment in household and shared water supplies, commonly known as Self-supply. Self-supply can be promoted by introducing and building local capacity in appropriate and affordable water supply technologies such as hand-dug wells, manually drilled boreholes, low-cost pumps, …

Bs News May/June

Building Services Engineering

No abstract provided.

Progressive Collapse Analysis Of Older Reinforced Concrete Flat Plate Buildings Using Macro Model, Jinrong Liu

UNLV Theses, Dissertations, Professional Papers, and Capstones

Catastrophic progressive collapse of a building can be triggered by a sudden loss of a load-bearing element in an abnormal loading event. There is a large inventory of reinforced concrete flat plate buildings designed in accordance with older codes. Without using shear and integrity reinforcement in slabs, these older flat plates are vulnerable to progressive collapse. The overall goal of this research is to numerically examine the resilience of older flat plate buildings against progressive collapse due to instantaneous removal of an exterior or interior column.

To achieve the research goal, a macro behavioral model of slab-column frame is created …

Reliability Analysis For Shear In Lightweight Reinforced Concrete Bridges Using Shear Beam Database, Danile F. Jensen

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The objective of this report is to analyze and calibrate the reliability indices for shear in reinforced concrete bridge girders. Existing statistical models are based on limited experimental data from only a few research tests. These existing models show that our current procedures for analysis are about 10-15% less conservative for lightweight concrete compared to an analysis for normal weight concrete. Accurate load models are used to find shear and moment envelopes of loads applied to bridges. Analysis is based on different span lengths, span number and girder dimensions. Design calculations are performed using design values and loads calculated from …

Highway Routine Maintenance Cost Estimation For Nevada, Monika Hagood

UNLV Theses, Dissertations, Professional Papers, and Capstones

State highway agencies are obligated to maintain existing roads for the highway systems to work efficiently and with greater longevity. Every year NDOT is responsible for approximately 13,150 lane miles of existing infrastructure. With that in mind, resources need to be provided to maintain the highway system.

The purpose of this research was to estimate annual routine maintenance cost for several typical treatment methods of highways. Five prioritization categories of highways used by NDOT were considered. Linear regression models were developed that present the relationship between costs including total maintenance cost and five maintenance cost components: labor, equipment, materials, manpower …

Modeling Of Short Term And Long Term Impacts Of Freeway Traffic Incidents Using Historical Data, Vidhya Kumaresan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Traffic incidents are major contributors to non-recurring traffic congestion in most urban areas in United States. In addition to losses in terms of injury and property damage, freeway incidents also produce negative effects on the system including increased travel delays, fuel consumption and vehicle emissions. Incident management strategies are aimed at reducing the impacts caused by such incidents. Development of guidelines or models to quantify the impacts of these incidents on the society can aid in analyzing the effectiveness and economic feasibility of such incident management strategies.

The first objective of this study is to calibrate models that relate the …

Simultaneous Equation Modeling For Crash Rate Of Freeway Segments, Anthony Ramos

UNLV Theses, Dissertations, Professional Papers, and Capstones

In 2010, the total number of reported traffic crashes in the state of Nevada was 51,664 of which 235 (0.6%) resulted in one or more deaths (Nevada Department of Transportation, 2012). The state's "Zero Fatalities" traffic safety campaign aims to reduce the rate even further. Out of the total number of crashes, Clark County (includes Las Vegas) accounted for 78.89%. This study examines safety improvement by developing advanced crash prediction models. The system of crash prediction equations consider geometric conditions and traffic volume using simultaneous equation modeling (SEM). The models are based on geometric characteristics and traffic volume data collected …

Influence Of Limestone Powder Content And Size On Transport Properties Of Self-Consolidating Concrete, Rebecca Kendal Spitek

UNLV Theses, Dissertations, Professional Papers, and Capstones

Self-consolidating concrete (SCC) requires higher cementitious materials content than conventional vibratory-placed concrete. This requirement leads to higher time-dependent properties (i.e., shrinkage (drying and autogeneous) and creep), increases formwork pressure, and results in a higher production cost. One alternative to alleviate excess creep and shrinkage, and to reduce cost, is to replace a portion of cementitious materials with mineral additives. The objective of this study was to examine the role of limestone powder, as a partial replacement of cementitious materials, on transport properties of self-consolidating concrete (SCC). A total of 10 different SCCs, including a control concrete, was prepared and test …

Investigating The Physical Properties And Runoff Treatment Capability Of Pervious Concrete Containing Granular Activated Carbon, Mark Elias Elkouz

UNLV Theses, Dissertations, Professional Papers, and Capstones

A current environmental concern is that of urban stormwater runoff, which can carry a multitude of contaminants and could threaten or impair surface waters. Pervious concrete (PC) is a type of concrete with significant void spaces that can facilitate infiltration and lead to less runoff. The EPA cites previous research to show that pervious pavement structures reduce such contaminants as metals and total suspended solids. Since Granular Activated Carbon (GAC) is a well-known contaminant adsorbent, the purpose of this research was to determine if PC with added GAC would result in improved runoff treatment, while still maintaining its material properties. …

Chemical And Hydrodynamic Mechanisms For Long-Term Geological Carbon Storage, Susan J. Altman, Wen Deng, For Full List Of Authors, See Publisher's Website.

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Geological storage of CO₂ (GCS), also referred to as carbon sequestration, is a critical component for decreasing anthropogenic CO₂ atmospheric emissions. Stored CO₂ will exist as a supercritical phase, most likely in deep, saline, sedimentary reservoirs. Research at the Center for Frontiers of Subsurface Energy Security (CFSES), a Department of Energy, Energy Frontier Research Center, provides insights into the storage process. The integration of pore-scale experiments, molecular dynamics simulations, and study of natural analogue sites has enabled understanding of the efficacy of capillary, solubility, and dissolution trapping of CO₂ for GCS. Molecular dynamics simulations provide insight on relative wetting of …

Post-Tensioning To Prevent End-Region Cracks In Pretensioned Concrete Girders, Michael Willis

All Theses

Web-splitting cracking during and immediately after prestress transfer is a common problem in pretensioned concrete beams, often with lasting effects on the durability and performance. By providing an entry point for chlorides and other corrosives, end-region cracks enable degradation of reinforcing steel and further cracking. Current practices offer a variety of methods for controlling end-region cracking. However, methods for preventing--not just controlling or repairing--end-region cracks are necessary to improve prestressed concrete construction. Vertical end-region post-tensioning is a developing method for preventing web-splitting cracks. The purpose of this document is to explore implementation methods of post-tensioning using the turn-of-the nut procedure, …

Development Of A Mash Tl-3 Transition Between Guardrail And Portable Concrete Barriers, David A. Gutierrez

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

Often, road construction causes the need to create a work zone. In these scenarios, portable concrete barriers (PCBs) are typically installed to shield workers and equipment from errant vehicles as well as prevent motorists from striking other roadside hazards. For an existing W-beam guardrail system installed adjacent to the roadway and near the work zone, guardrail sections are removed in order to place the portable concrete barrier system. The focus of this research study was to develop a proper stiffness transition between W-beam guardrail and portable concrete barrier systems. This research effort was accomplished through development and refinement of design …

A Junction Tree Based Reinforcement Learning Algorithm For Coordinated Multi Agent Systems To Solve Network Level Signal Control Problems, Feng Zhu, Husain M. Abdul Aziz, Zinwu Qian, Satish Ukkusuri

Purdue Road School

No abstract provided.

A Meta-Heuristic Approach To Reposition Bicycles In A Public Bicycle Sharing System, Binh Luong, Pulkit Parikh, Satish Ukkusuri

Purdue Road School

No abstract provided.

Concrete Conductivity: Effects Of Temperature, Saturation And Air Content, Parth Panchmatia, Jan Olek, Nancy Whiting, Mike Byers, Tommy Nantung

Purdue Road School

No abstract provided.

Examining The Impact Of Pavement Rehabilitation Trigger Values And Annual Rehabilitation Funding On The Long-Term Network-Level Pavement Condition: A Case Study With The Indiana State Urban Road Network, Menna Noureldin, Jon D. Fricker, Kumares C. Sinha

Purdue Road School

Management of highway assets, including pavements, is immensely challenging in an era of uncertain funding for transportation agencies and higher service expectations from the public. Furthermore, the maintenance of pavement assets in good serviceable condition is one of the most cost-intensive operations for a highway agency.

Between 1996 and 2008, the Indiana DOT spending on improvement of pavement assets fluctuated between 35% and 50% of its asset management budget annually (Everett2012). Therefore, pavement managers are constantly exploring strategies to fulfill their mission of maintaining roads in good condition with the minimumbudget. Strategies may include examining the effectiveness of individual pavement …

Winter Storm Interstate Travel Times (January 5, 2014 Storm), Michelle Mekker, Darcy M. Bullock

Purdue Road School

No abstract provided.