Engineering Commons^™

Investigation Of The Experimental And Numerical Flexural Behavior Of Innovative Totally Encased Composite Beams, Nour Wehbi, Adnan Masri, Oussama Baalbaki

BAU Journal - Science and Technology

Composite steel-concrete beams have been widely used in long span construction and high rise buildings due to their favorable behavior in terms of high strength, stiffness, and ductility. In this research, the flexural behavior of an innovative steel-concrete composite section is investigated experimentally and verified numerically using ABAQUS software. The studied section is composed of steel tubular specimen or steel hollow pipe totally encased in concrete in the absence of any flexural or shear reinforcement. Instead, steel mesh wraps are used around the tubular steel specimen to provide sufficient steel-concrete bond. All of the studied beams have the same 3m …

Truss Bridge Damage Localization And Severity Estimation Using Influence Lines, Hamoud Alshallaqi

Civil and Environmental Engineering Theses and Dissertations

The safety of bridges is one of the primary concerns of researchers, engineers, and bridge owners and managers, especially when bridges are approaching the end of their intended service lives. The estimation of bridge condition and remaining service life is critical to prioritize the allocation of available funding for repairs and rehabilitation. Various methods, including both dynamic and static approaches, have been developed to detect and localize bridge damage and estimate its severity. This research presents a methodology for detecting a single damaged member in a truss bridge and estimating the severity of the damage using static vertical deflection influence …

Thermal And Mechanical Numerical Modeling Of Extrusion-Based 3d Printed Reinforced Polymers For Selecting Manufacturing Process Parameters, Sunil Bhandari

Electronic Theses and Dissertations

Extrusion-based 3D printing of thermoplastic polymer composites manufactures parts that have nonhomogenous, orthotropic, and process-dependent macro-scale material properties. As a part of the dissertation, research works were carried out to: • improve the interlayer mechanical properties and reduce the orthotropy, • use experimentally homogenized orthotropic material properties to numerically model the mechanical behavior of the non-homogenous orthotropic 3D printed parts, • create an efficient numerical thermal model to predict the process-dependent thermal history of the 3D printed part, and • aid the manufacturing process by selecting a suitable set of processing parameters based on a simplified sequentially coupled thermomechanical model. …

Behavior Of Wind Turbine Towers And Blades Under Tornado Wind Fields, Mohamed Abugazia

Electronic Thesis and Dissertation Repository

The installation rate of wind turbines around the world is increasing significantly. Therefore, wind turbine farms are constructed in plentiful wind resources areas that put a considerable number of wind turbine towers under severe wind conditions. As a result, failures due to unexpected wind loads on either the blades or the tower are increasing. In addition, wind turbines are designed to resist synoptic wind loads as per the current guidelines, which do not consider high-intensity wind (HIW) events such as tornadoes. The built-in-house numerical code “HIW-WT” has been developed in this study to model wind turbines under three-dimensional wind fields …

Field Durability Test Of Clt Wall Envelope Using Physical Barriers Against Termites And Structural Performance Of Nailed Hold-Down Brackets Connected To Fungus-Exposed Clt Walls, Kamal Neupane

Theses and Dissertations

The effectiveness of using commercial polyethylene flashing and stainless-steel mesh in CLT wall systems as the termite barriers were evaluated in a short-term field test. American Wood Protection Association (AWPA) E21's visual ratings ranged from 10 to 9 in the specimens showing little damage when no physical barriers were used. Termites were able to crawl beyond the physical barriers in few specimens showing the necessity of further research on height and installation method of physical barriers. On the second part, the effect of decay caused due to Postia placenta, a brown-rot fungus, on the structural performance of hold-down brackets connected …

Mixing Temperature, Binder Content, And Dust Content Effects On Stone Matrix Asphalt, Abhinash Subedi

Theses and Dissertations

This study focuses on the effects of mixing temperature, binder content, and dust content on the performance of Stone Matrix Asphalt (SMA). Mixes produced at different mixing temperatures and with or without added polymer modified binder (P_b) and/or bag house dust (BHD) were evaluated. Two different types of specimens: laboratory mixed laboratory compacted, and plant mixed laboratory compacted were evaluated by Cantabro Mass Loss (CML) testing in an unaged condition or after a laboratory conditioning protocol (CP) was applied. Additional P_b and BHD were added to plant produced mixes in the laboratory before mixing. Results showed that …

Effects Of The Checks, Andrew Stott

Fall Student Research Symposium 2021

As a result of the COVID-19 pandemic, thousands of people have lost thousands of dollars, and some much more. As a result, the government issued aid in the form of stimulus checks, with the intention to stimulate the economy and compensate for money lost. The government is not adding value to the economy, but merely moving it around, and in many cases simply making it worse. The checks allude to an even bigger issue: that of universal income and welfare checks. Although these things may be helpful to the individual, they are ineffective and harmful to the economy because they …

A Simplified Stress Analysis Of Functionally Graded Beams And Influence Of Material Function On Deflection, Elias Ali

Faculty Scholarship

This paper aims at providing a simplified analytical solution for functionally graded beam stress analysis and optimized material gradation on the beam deflection. The power-law (P-FGM) and exponential (E-FGM) material functions were considered for an exact solution of the normal and shear stress distributions across the beam thickness. Optimization of material function on the FGM beam deflection, which is new of its kind, was also investigated considering both simply supported and cantilever beams. It was observed that the non-dimensional normal stress and shear stress are independent of the elastic moduli values of the constituent materials but rather depends on both …

Additive Manufacturing Of Soil Using Bio-Cementation, Christina Childress

Graduate Theses and Dissertations

Microbially Induced Calcite Precipitation (MICP) is an emerging soil treatment technique that is proven to increase strength, decrease erosion, reduce liquefaction risk, enhance slope stability, decrease compressibility, decrease swelling potential, and overall create a more competent soil. The benefits and applications of MICP are broad, and this research seeks to broaden them further by developing a single-phase additive manufacturing application with no treatment time delay. This is done by analyzing layering behaviors of five USCS soil classifications (100 % Ottawa sand, sand clay mixtures, and 100% lean clay) which provides insight into process variables such as the solution volume and …

An Investigation Of The Flexural Strength And Toughness Of Hybrid Plain And Fiber Reinforced Concrete For Pavement Applications, Wesley Keys

Graduate Theses and Dissertations

For decades, many solutions have been evaluated to combat cracking in concrete pavements. The study presented in this paper evaluates and compares the flexural performance under a third point loading configuration of plain concrete (PC) beams, fully fiber reinforced concrete (FRC) beams, and hybrid PC and FRC beams, with a top PC and bottom FRC layer. The purpose of this hybrid approach was to provide FRC in only half the section, saving cost, while providing a PC surface layer that is easier to finish. All PC top layers were applied at an age of 7-days, considered a reasonable time for …

Retrospective Analysis Of Impacts Of Highway Bypass And Widening Projects, Sanjeev Bhurtyal

Graduate Theses and Dissertations

Community members often worry that highway projects may have negative impacts on their local economies. This is typical for highway bypass and widening projects in small cities (population less than 50,000). It is a challenge for planners to balance public concerns of economic decline with desired project outcomes of mobility and safety. Much of this challenge stems from a lack of information on post-project outcomes related to economic and safety impacts of new construction projects. Thus, there is a need for an evidence-based framework to help planners with the decision-making process and better inform the community on potential outcomes. This …

Shear Strength Of Concrete Beams Made With Belitic Calcium Sulfoaluminate Cement, Caleb W. Chesnut

Graduate Theses and Dissertations

The need for a cleaner alternative to portland cement (PC) concrete has led to increasing interest in alternatives to PC. Structural properties of most of these alternative cements are still an open research topic. One promising alternative cement is belitic calcium sulfoaluminate (BCSA) cement. The study presented in this paper investigated the shear strength, long term compressive strength, and carbonation in BCSA cement and PC concrete beams. A total of twelve eight-foot long beams were made; eight BCSA cement concrete beams and four PC concrete beams to be tested at various ages depending on cement type. Two beams of each …

Effect Of Various Speed Management Strategies On Bicycle Crashes For Urban Roads In Central Florida, Jorge Ugan

Electronic Theses and Dissertations, 2020-

In recent years, cycling has become an increasingly popular transportation mode around the world. In contrast to other popular modes of transportation, cycling is more economic and energy efficient. While many studies have been conducted for the bicycle safety analysis, most of them were limited in terms of bicycle exposure data and on-street data. This study tries to improve the current safety performance functions for bicycle crashes at urban corridors by utilizing crowdsource data from STRAVA and on-street speed management strategies data. Speed management strategies are any roadway alterations that causes a change in motorists' driving behavior. In Florida, these …

Improving Pedestrian Safety With The Implementation Of The Demand-Responsive Transverse Rumble Strip As A New Traffic Safety Countermeasure, Md Shakhawat Hossen

UNLV Theses, Dissertations, Professional Papers, and Capstones

The traditional TRS has been extensively used as a traffic calming device to provide cognitive alerts in the form of sound and vibration to drivers. However, TRS always remains fixed on the road and thus exerts cognitive alerts, irrespective of any potential downstream hazards. Moreover, the continuous exposure to rumble strips has been identified as a source of discomfort and annoyance for drivers, which limits its application to potentially useful scenarios. This study explores a rumble strip design with dynamic behavior named as Demand-Responsive Transverse Rumble Strip (DRTRS) in order to address the limitations of static TRS. The study incorporates …

Quaternary Ammonium Compounds As Precursors To Disinfection Byproducts, Padmanabhan Krishnaswamy

UNLV Theses, Dissertations, Professional Papers, and Capstones

Disinfection of drinking water is crucial for providing a safe potable water supply. Some of the most common disinfectants employed are chlorine, chloramines and ozone. While these disinfectants successfully inactivate pathogenic microorganisms, they simultaneously react with inorganic or organic precursors to form toxic byproducts, most commonly referred to as disinfection byproducts (DBPs). While there is a wide variety of organic matter and disinfection byproducts known, in this study we have looked into the potential of certain quaternary ammonium compounds (QACs) to act as precursors to form DBPs, namely trihalomethanes (THMs), haloacetonitriles (HANs) and nitrosamines.

The ubiquitous nature of QACs in …

Drying Of Digested Biosolids For Weight Reduction Prior To Disposal, Juan Manuel Canales

Open Access Theses & Dissertations

Disposal of belt filter pressed digested sludge (known as biosolids) to landfills cost El Paso Water about $1.1 million in the past year. With an increasing population, the amount of influent wastewater to El Paso treatment plants will also increase, resulting in increased biosolids generation and biosolids disposal costs. A method for reducing biosolids transportation cost is biosolids drying.The cost that El Paso Water pays for transporting biosolids to a dedicated landfill facility is based on the weight of the biosolids that are carried. Biosolids collected from the belt filter presses is about fifteen percent solids by weight, with water …

Structural Impacts Of Super Heavy Load (Shl) Vehicles On Transportation Infrastructure, Ali Morovatdar

Open Access Theses & Dissertations

Operation of non-conventional Super Heavy Load (SHL) vehicles is an ongoing challenge for transportation stakeholders and the traveling public across the nation. Despite facilitating the movement of heavy, large, and non-divisible loads, passages of such vehicles with complex loading configurations that typically weigh several folds of the permissible weight limits set forth by regulatory agencies have been adversely affecting the structural integrity of pavement facilities. This translates into accelerated damage of pavement structures, which in turn poses safety concerns for users of the transportation facilities. Accurate quantification of such detrimental impacts is the precursor to preserve the existing transportation facilities. …

Building Energy Model Simulation Of A Single Building In Comparison To A Broader Building Stock, Paola Michelle Santillano

Open Access Theses & Dissertations

Residential facilities and buildings are the largest consumers of energy in the United States. More than 76% of electricity and more than 40% of all energy consumption comes from providing a comfortable and healthy environment in buildings. Prioritizing building energy technology goals for performance and cost can significantly reduce energy use within the next ten years despite a substantial forecasted population increase. Retrofitting existing buildings and improving future construction has the potential to realize cost savings and environmental benefits over time. A key component to realizing these benefits is regional building energy modeling. One of the challenges to widespread building …

Magnetorheological Cementitious Inks For 4d Printing Of Origami Inspired Auxetic Concrete Elements, Aparna Shashikant Deshmukh

Theses and Dissertations

Existing concrete technology relies on the use of considerable volumes of raw materials, large energy consumption and so associated with severe corresponding environmental impacts. This impact is the driving force for the development of sustainable concrete including a wide range of concrete with supplementary cementitious materials and advanced manufacturing. Recent developments in the field are further inspired by the digital concrete based on 3D printing (3DP) technology which require tailor-made concrete mixtures. The main challenge for 3D printing of concrete is to develop printable ink material, thus this research focuses on characterisation of cementitious materials based on smart materials-materials that …

Seismic Performance Assessment Of Building Contents: Monetary Losses And Injuries, Sereen Majdalaweyh

All Dissertations

Building contents include all the components that are not attached to the building which the owners place after the construction phase, such as furniture, electrical equipment, glassware, and other personal items. Loss and damage assessment of building contents proved to be challenging in performance-based earthquake engineering frameworks because of the data sparsity. Damages to building contents during an earthquake not only cause monetary losses; tumbling and over-toppling of heavy building contents could result in injuries and even deaths of occupants. While major advancements have been made in performance-based earthquake engineering; however, the focus is mainly on damages and collapse risk …

The Impact Of Increasing Flood Frequency On Flood Inundation: A Case Study Of The Little River In Florida, Maj Amanda Catharina Allen

Theses and Dissertations

Floods are considered one of the most devastating natural hazards and are projected to increase in frequency and magnitude in many places around the world, one of them being Florida. Understanding the potential changes of flood hazards due to climate change is of paramount importance for developing effective flood mitigation procedures and resilient infrastructures. In this work, changes in flood inundation characteristics (flood depth and extent) in response to changes in future flood magnitudes are estimated and analyzed for the Little River basin in northwest Florida. HEC-RAS hydraulic model is set up and validated against observations for the flood event …

Data Driven Methods For Large Scale Network Level Traffic Modeling, Rezaur Rahman

Electronic Theses and Dissertations, 2020-

Rapid growth in population along with urban-centric activities impose a massive demand on existing transportation systems, thus increasing traffic congestion and other mobility related challenges. To overcome such challenges, we need network-scale models to accurately predict real-time traffic demand and associated congestion. However, traditional network modeling approaches have shortcomings due to the complexity in traffic flow modeling, limited scope to incorporate real-time data available from emerging data sources and requiring excessive computation time to generate accurate estimation of traffic flows. Advancement in traffic sensing technologies with big data has created a new opportunity to overcome these challenges and implement deployable …

Hybrid Structural Health Monitoring Using Data-Driven Modal Analysis And Model-Based Bayesian Inference., Jice Zeng

Electronic Theses and Dissertations

Civil infrastructures that are valuable assets for the public and owners must be adequately and periodically maintained to guarantee safety, continuous service, and avoid economic losses. Vibration-based structural health monitoring (VBSHM) has been a significant tool to assess the structural performance of civil infrastructures over the last decades. Challenges in VBSHM exist in two aspects: operational modal analysis (OMA) and Finite element model updating (FEMU). The former aims to extract natural frequency, damping ratio, and mode shapes using vibrational data under normal operation; the latter focuses on minimizing the discrepancies between measurements and model prediction. The main impediments to real-world …

Spatiotemporal Variations Of Precipitation And Climate-Resilient Structure Design In Virginia, Xiaomin Yang

Civil & Environmental Engineering Theses & Dissertations

How to consider effects of climate change on the design and management of hydrology related infrastructure is crucial but remains a challenge for sustaining resilient society. To address this challenge, existing hydrologic design procedures may need to be revised and/or redeveloped to take into account the precipitation non-stationarity resulting from climate change. Using the state of Virginia as a testbed and advanced statistical techniques such as nonparametric test, spatial autocorrelation, linear regression, distribution fitting, and spatial interpolation, this dissertation developed an innovative framework to detect the historical spatiotemporal variations of various precipitation characteristics, namely maximum precipitation intensity, precipitation amount, simple …

Building And Infrastructure Defect Detection And Visualization Using Drone And Deep Learning Technologies, Yuhan Jiang, Sisi Han, Yong Bai

Civil and Environmental Engineering Faculty Research and Publications

This paper presents an accurate and stable method for object and defect detection and visualization on building and infrastructural facilities. This method uses drones and cameras to collect three- dimensional (3D) point clouds via photogrammetry, and uses orthographic or arbitrary views of the target objects to generate the feature images of points’ spectral, elevation, and normal features. U-Net is implemented in the pixelwise segmentation for object and defect detection using multiple feature images. This method was validated on four applications, including on-site path detection, pavement cracking detection, highway slope detection, and building facade window detection. The comparative experimental results confirmed …

Relating The Dongre Workability Test To Cold In-Place Recycled Asphalt Pavements, Gus Williams

Civil Engineering Undergraduate Honors Theses

The Dongre Workability Test (DWT) is a test for determining an asphalt pavement’s relative workability from the stress-strain curve of a sample. While the DWT has seen favorable results with warm mix and hot mix asphalt, Casillas and Braham (2020) attempted to apply this test to cold in-place recycled (CIR) asphalt pavements with limited results. This paper looked at the process of reexamining the DWT method to more favorable results with CIR samples. Phase 1 consisted of defining ten possible metrics from the stress-strain curve and applying them to samples with three different curing conditions. From these preliminary results, the …

Development And Promotion Of Mass Timber Noise Barrier For Highways, Harsh Bothra

All Theses

Highways are some of the biggest causes of noise pollution in the United States of America. To deal with the traffic noise coming from these highways, noise barriers have been erected across major highways. The goal is to reduce as much noise as possible through a sustainable solution. Unfortunately, the use of steel and concrete, commonly used materials, have undesired environmental impacts. A suggested sustainable alternative material would be mass timber. Mass timber products such as cross-laminated timber (CLT) and mass plywood panels (MPP) has attracted the attention of the construction industry in the U.S, as they are sustainable, light, …

Chasing Target Zero: Contributing Factors Of Fatal Crashes In South Carolina, Matthew Stanley

All Theses

South Carolina consistently ranks in the top-10 in fatal crashes per 100,000 capita and 100 million vehicle miles traveled. This thesis summarizes an analysis of contributing factors for fatal crashes in South Carolina. A primary objective of this thesis is to investigate differences in contributing factors for fatal crashes as compared to all crashes in South Carolina. 2018 South Carolina fatal crashes (N=970) and all crashes (N=152,973) were analyzed and compared using classic Venn diagrams to compare differences in contributing factors between fatal crashes and all crashes. Fatal, non-fatal, and all crashes were aggregated into one of seven possible contributing …

Deriving Generalized Temperature-Dependent Material Models For Masonry Through Fire Tests And Machine Learning, Aditya Avinash Daware

All Theses

Masonry is one of the oldest and commonly used building materials in the construction industry. Among a variety of benefits, masonry provides low-cost construction, fire, and weather protection as well as thermal and sound insulation. In addition, masonry has superior material properties at elevated temperatures which is reflected by its slow degradation of its mechanical and thermal properties. Literature shows that we do not have a uniform material model that describes the mechanical degradation of masonry under fire conditions. As such, this limits the use of masonry in fire-based performance design of masonry structures. To bridge this knowledge gap, this …

A Linear Dynamical Perspective On Epidemiology: Interplay Between Early Covid-19 Outbreak And Human Mobility, Shakib Mustavee

Electronic Theses and Dissertations, 2020-

This research investigates the impact of human activity and mobility (HAM) in the spreading dynamics of an epidemic. Specifically, it explores the interconnections between HAM and its effect on the early spread of the COVID-19 virus. During the early stages of the pandemic, effective reproduction numbers exhibited a high correlation with human mobility patterns, leading to a hypothesis that the HAM system can be studied as a coupled system with disease spread dynamics. This study applies the generalized Koopman framework with control inputs to determine the nonlinear disease spread dynamics and the input-output characteristics as a locally linear controlled dynamical …