Engineering Commons^™

Plastic Deformation Of Steel Plates Under High Velocity Impact, Shawoon Kumar Roy

College of Engineering: Graduate Celebration Programs

• Measure material deformation under high velocity impact.
• Explore the capabilities of the newly developed Multiplexed Photonic Doppler Velocimetry (MPDV) system.
• Study factors that affect the accuracy of computational techniques to simulate high velocity impact.

Long-Term Behavior Of Hygrothermaly Conditioned Concrete-Filled Fiber-Reinforced Polymeric Tubes Subjected To Axial Load, Sergio Arambula, Felipe Acosta

Purdue Road School

No abstract provided.

A Comparison And Evaluation Of Different Dynamic Characterization Approaches For Bridges, Juan Javier Torres Torres Goitia

Graduate Theses and Dissertations

The objective of this thesis was to compare different dynamic characterization approaches for full scale bridge structures to devise a rapid and reliable Structural Health Monitoring (SHM) program in the aftermath of a natural or manmade hazard. Present methods for structural condition evaluation of bridge structures rely heavily on on-site visual inspections of each structure by specially trained engineers and technicians. It has been proved in the literature that this current method is subjective, time consuming and manpower intensive, all of which are not suited for the critical conditions following a hazard event. This study focused on comparing three different …

Comparing Ferrous Chloride And Ferrous Sulfate As Secondary Coagulants At The Beaver Water District Drinking Water Treatment Plant, Jenny Doyle

Graduate Theses and Dissertations

In November 2012, the Beaver Water District (BWD) switched primary oxidants from free chlorine to chlorine dioxide (ClO2) to curb formation of trihalomethanes, a regulated group of organic disinfection byproducts (DBPs). Because ClO2 is reduced to chlorite (ClO2-), a regulated inorganic DBP, BWD incorporated ferrous salt into their coagulation regime to quench chlorite to chloride. In this study, two ferrous salts - ferrous chloride (FC) and ferrous sulfate (FS) - were compared as secondary coagulants in combination with alum, the primary coagulant. Ferrous salts were dosed stoichiometrically to reduce chlorite and alum was dosed at percentages (0-100%) relative to a …

Global Dynamic Characterization And Load Rating Of Bridge Structures Utilizing Economical Dynamic Excitation Devices, Eric Fernstrom

Graduate Theses and Dissertations

Experimental modal analysis (EMA) of bridges and other civil structures can be used to acquire quantitative data describing their condition, and enhance opportunities for structural health monitoring and related fields. The use of EMA on civil structures has been limited by the high cost of the excitation devices that are required for the best data quality. The objective of the research reported herein is to evaluate a low-cost excitation system for multiple-input, multiple-output (MIMO) EMA, enabling the production of accurate estimates of the global behavior of in-service bridges.

The prototype excitation system is composed of consumer entertainment devices, namely tactile …

Rapid Condition Assessment Of Bridges By Falling Weight Deflectometer, Jeremy David Rawn

Graduate Theses and Dissertations

The objective of this thesis is to investigate the feasibility of using a Falling Weight Deflectometer (FWD) as an impact source to rapidly assess the condition of an in service bridge through the evaluation of its modal properties. Tests were conducted on two bridges, a Parker Pony Truss and a modern concrete deck on rolled steel beam bridge. Two full tests were performed on these structures with a hand held impact hammer and a falling weight deflectometer as sources for excitation. The advantage of using a FWD is that many transportation agencies already use these machines for pavement testing and …

The Investigation Of Cold-Mix Asphalt Creep Stiffness Testing Using Multiple Test Apparatuses And Gradations, Alexander Jackson

Graduate Theses and Dissertations

Many current methods of designing and testing Cold In-Place Recycled (CIR) asphalt are undesirable because they require large amounts of material and significant preparation. In an effort to lessen the cost and time of materials testing, this research utilizes several different methods of small scale testing of creep stiffness. These methods include using a Discovery Hybrid Rheometer (DHR) and a three point bending test to find the creep stiffness of emulsion based CIR. The new testing methods utilized samples on the scale of up to a hundredth the size of what the traditional methods of testing require. The two smaller …

The Characterization Of Foamed Asphalt Binders Using A Rotational Viscometer, John William Ryan

Graduate Theses and Dissertations

Foamed asphalt is a popular technic of vaporizing water into asphalt binder that falls under the umbrella term of warm-mix asphalt. In order to understand how to adjust mix designs for the use foamed asphalt, methods must be developed for characterizing different foamed asphalt binders. One way to characterize the asphalt binder is through viscosity testing using a rotational viscometer. The standard method of using a viscometer to measure the viscosity of asphalt binder is insufficient when dealing with foamed asphalts, so a new method has been created along with 4 metrics to analyze the data to characterize foamed asphalt …

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 …

Investigation Of Warm Mix Asphalt Overlays And Geosynthetic Pavement Interlayers, William Bolger

All Theses

Geosynthetics play an ever increasing role in enhancing pavements. The construction of asphalt overlays with geosynthetic interlayers is a common method to rehabilitate flexible and rigid pavements. Geosynthetic interlayers provide numerous benefits to a pavement system. When utilized properly, geosynthetic interlayers can prevent water from infiltrating a roadway base and can extend the life of a pavement and assist in absorbing stresses. Geoysnthetics lead to an increase in a pavement overlay's performance and also retard reflective cracking. Warm mix asphalt has become more popular as a result of the search for more sustainable construction practices. WMA and its technologies are …

Effect Of Particle Shape And Size On Compressibility Behavior Of Dredged Sediment In A Geotextile Tube Dewatering Application, Louis Lafata

Renée Crown University Honors Thesis Projects - All

Each year, more than 250 million cubic yards of sediment need to be dredged from U.S. ports, harbors and waterways to maintain navigability. This is accomplished by dredging, the process of excavating submerged sediment by means of scooping or suction. Dredged sediments have low solids content, typically between 10% and 20% for hydraulic dredging. Geotextile tubes are one of many methods utilized to dewater these sediments, which is a process of removing water from sediment that contains low percent solids. Understanding the engineering behavior of slurries inside geotextile tubes is critical for the evaluation of the properties of the dewatered …

Clemson University Science Master's Program In Sustainable And Resilient Infrastructure: A Program Evaluation, Elizabeth O'Sell

All Theses

The Clemson University Science Master's Program (SMP) in Sustainable and Resilient Infrastructure is a program which aims to link engineering, materials, construction, environment, architecture, business, and public policy to produce graduates with unique holistic perspective and expertise to immediately contribute to the workforce in the area of sustainable and resilient infrastructure. A program evaluation of the SMP has been performed to study the effectiveness of the SMP and identify areas where the goals and vision of the SMP are achieved and areas where improvements can be made. This was completed by analysis of trends within survey responses, review of Master's …

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, …

Preliminary Evaluation Of Kenaf As A Structural Material, Andrew Sheldon

All Theses

Kenaf (Hibiscus cannabinus L.) is an annual fiber plant that is kin to cotton and okra and native to east-central Africa, though it is currently grown in numerous locations around the globe. The plant's apparent high strength and light weight along with its environmental and sustainability advantages makes it a good candidate for use in structural materials. The goal of this study was to design a kenaf product that resembled parallel strand lumber and required minimal processing of the kenaf. The mechanical properties of the two main components of kenaf, the bast fibers and the core, were evaluated using experimental …

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 …

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. …

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 …

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 …

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 …

Developing A South Carolina Traffic Incident Management Plan Along The I-26 Corridor Between Columbia And Charleston, Laura Rowe

All Theses

Traffic Incident Management (TIM) programs are used in many states across the nation to efficiently clear interstate incidents and alleviate congestion in response to incidents. The overarching goal of this research is to maintain safety of the motoring public and incident responders while reducing congestion, secondary collisions, and traffic delays from incidents that occur on South Carolina highways. To reduce incident clearance times along the I-26 corridor between Columbia and Charleston through the implementation of a Traffic Incident Management (TIM) Program, several objectives for this thesis were established to move toward the goal, including; defining gaps between national TIM best-practices …

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 …

Development Of A Visualization System For Highway Safety Management Using Safety Analyst, Indira Khanal

UNLV Theses, Dissertations, Professional Papers, and Capstones

The AASHTOWare software, Safety Analyst, is a state-of-the-art tool with significant capabilities and advanced analytical methods for comprehensive analysis and management of highway safety. However, currently, this tool provides very limited visualization capabilities. To address this limitation, this study proposes a Visualization System for Safety Analyst that provides graphical displays, including location and color-coded information for each module. In addition, the system generates charts, which have various degrees of resolution and aggregation; tables; and a report summarizing safety performance measures. The system can use Google Maps and/or ESRI ArcGIS to generate the graphical displays. The advantage of using Google Maps …

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 …