Civil Engineering Commons^™

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 …

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 …

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 …

Improve The Prediction Of Camber, Deflection, And Prestress Losses In Precast, Prestressed Concrete Bridge Girders, Ahmed Ali Hussein Al Mohammedi

Graduate Theses and Dissertations

Many precast, prestressed concrete girders have camber less or higher than the design values. This discrepancy between the design and the actual camber creates construction problems when installing the cast-in-place concrete deck. The objective of this research was to improve the accuracy of estimating long-term camber, deflection, and prestress losses of precast, prestressed concrete girders.

The experimental program consisted of measuring concrete properties and performing field measurements of camber, deflection, and prestress losses for girders in Arkansas. The investigation involved testing nine full-scale girders from two prestressed concrete plants that regularly supply concrete girders to bridge projects in Arkansas. The …

Formation Of Reactive Nitrogen Species During Dichloramine Decay And Their Impact On N Nitrosodimethylamine Formation Under Drinking Water Conditions, Huong Thu Pham

Graduate Theses and Dissertations

NDMA occurrence and formation pathways in drinking water systems are reviewed and NDMA yields are compared on the basis of disinfectant type, water chemistry, and precursor category. In chloramination, despite monochloramine being the predominant species between pH 7-9, evidence suggests that dichloramine is the primary species involved in NDMA formation. This is somewhat confounding as NDMA yields are maximal at pH 9, yet at pH 9 dichloramine decays faster than it forms and hence is present at trace levels; additionally, the proposed mechanism involves a spin-forbidden incorporation of dissolved oxygen as a triplet, which is presumably kinetically slow. This review …

Role Of Binder Compositions And Carbonate Polymorphs On The Performance Of Carbonation Activated Cementitious Composites, Mohammad Rakibul Islam Khan

Civil Engineering Dissertations - Archive

The most energy-intensive manufacturing industry in the US is the Ordinary Portland Cement (OPC) industry. This industry is responsible for 5-8% of global CO2 emissions caused by humans. The calcination of limestone to produce high lime calcium silicate and high manufacturing temperature (1450°C) are responsible for this significant amount of CO2 emissions. This CO2 footprint of the cement-based composites can be decreased by utilizing cementitious materials with low-lime calcium silicate. Low-lime calcium silicates are typically semi-hydraulic or non-hydraulic. As a result, it is necessary to activate those materials in order to increase their reactivity. Alkali activators, carbonation curing (CO2 curing), …

Rainfall-Induced Slope Failure – An Early Warning System, Md Aminul Islam

Civil Engineering Dissertations - Archive

Globally, slope failures cause substantial death tolls and economic loss. Embankments constructed on high plasticity clay are vulnerable to cyclic swelling and shrinkage when subjected to climate. Thus, over time, soil softens and reduces effective shear strength, and shrinkage cracks on slopes can act as pathways for rainfall infiltration, which increases pore water pressure and lowers the shear strength below critical levels, resulting in slope failure. This study aims to develop early warning criteria for rainfall-induced slope failure. Study areas were Tarrant, Dallas, Johnson, and Ellis, where soil types and a humid subtropical climate result in frequent slope failures. The …

Assessment Of Stormwater Infrastructure For Mitigating Flooding And Non-Point Source Pollution, Helia Farzaneh

Civil Engineering Theses - Archive

Flooding is the top natural hazard impacting coastal and inland communities in Texas. Beyond its destructive impact on rising waters in communities, flooding-induced stormwater negatively affects the quality of large bodies of water. Stormwater runs over land, washes off pollutants, and deposits them into rivers which causes water quality issues in bays and estuaries. In addition, the stormwater increases nutrients, sediments, oxygen-demanding substances, pathogens, and toxins which results in hypoxia in the aquatic system. During the last 5-6 years, severe storm events such as Tropical Storm Beta (September 2020), Tropical Storm Imelda (September 2019), Hurricane Harvey (August 2017) have caused …

Fire Performance Of Hybrid Fiber Reinforced Self-Consolidating Concrete (Hfrscc) With Glass Pozzolan, Rishabh Kumar

Civil Engineering Theses - Archive

This research focuses on the effects of hybridizing self-consolidating concrete (SCC) using steel (SF) and polypropylene (PP) fibers to study their benefits post-fire exposure. In an attempt to reduce cement’s environmental impacts and to make concrete more sustainable, this research also studies the substitution of cement using glass pozzolan. Limited research has been done in this regard previously, hence this research makes an effort to bridge the enormous knowledge gap. No research has reported tensile, compressive, and flexural strength of SCC with hybrid fibers and glass pozzolan, making this research unique. Based on previous research, the replacement rate of cement …

Performance Evaluation And Retrofitting Options For An Impact Damaged Non-Composite Steel Girder Bridge, Mohd Mezanur Rahman

Civil Engineering Dissertations - Archive

The Federal Highway Administration (FHWA) has rated about 32% of total bridges in US as structurally deficient or functionally obsolete. One of the most frequently encountered issues for this deficiency is the impact created by cars that exceed the posted clearance for a bridge. Impact damage leads to concrete spalling or cracking, exposed or broken reinforcement/prestressing strands, global and local buckling of the structural member or piercing through the steel girder. For Example, St. Francis Bridge (North Bound) carrying St. Francis Avenue over I-30 east of downtown Dallas was impact damaged by an eighteen-wheeler carrying a heavy-duty wrecker on 29th …

Connected And Automated Vehicles: Their Implication On Capacity Of A Basic Freeway Section And Impacts On Walkway Safety, Sia Macmillan Lyimo

Dissertations

Autonomous vehicles have recently gained the attention of researchers due to their expected potential benefits on highway traffic streams, such as improving roadway capacity, among others. It is imperative to investigate how these expected benefits can be leveraged in the transportation sector. Understanding the safety and operational benefits helps the concerned transportation agencies and other key stakeholders to make necessary infrastructural and policy adjustments to accommodate such future traffic operation changes. The main goal of this dissertation is to study the impact of connected and automated vehicles on freeway capacity. The simulated environment was created to emulate autonomous vehicle behaviors, …

Evaluation Of Geotechnical Parameters Of Soil Using Electrical Resistivity Imaging, Md Asif Akhtar

Civil Engineering Dissertations - Archive

Electric resistivity imaging (ERI) is an effective non-destructive and rapid measuring way of obtaining continuous soil subsurface resistivity profiles. An ERI technique can be used to identify moisture variations and soil heterogeneities in an area. Thus, ERI is becoming a popular tool in geotechnical (FHWA, 2015)engineering; however, it only provides qualitative information at the current time. Using qualitative images, it is challenging to extract quantitative geotechnical information, such as the type of soil, moisture content, degree of saturation, and atterberg limit, of the subsurface. Several studies have described the electrical resistance of soil as a function of pore fluid conductivity …

Change In Sedimentation Regime Due To Bridge Construction Activities: A Field Study At Fm 2478 Bridge Over Wilson Creek, Mckinney, Texas, Subhas Kandel

Civil Engineering Theses - Archive

Bridge construction activities can cause soil disturbances that introduce sediments into a receiving stream and potentially impact its quality and the ecosystem. The impacts of bridge construction activities are studied in two ways: overland erosion and in-stream sediment concentration. For this research, the overland erosion of Wilson Creek in McKinney, Texas was monitored from four erosion plots constructed on its banks, near the bridge construction activities zone. The instream water quality was examined during the construction period by measuring the Total Suspended Solids (TSS) and the turbidity of water samples, and the sediment and water samples were collected and analyzed …

Carbon Footprint Assessment And Emissions Reduction Strategies For The University Of Texas At Arlington, Dravid Sabarish Villavan Kothai

Civil Engineering Theses - Archive

In the past decade, many universities have started to ascertain their emissions and benchmark their progress towards sustainability and climate control. The University of Texas at Arlington (UTA) is no exception in working toward the goal of carbon neutrality. While UTA continues to grow and transform, its goal is to simultaneously reduce energy intensity and greenhouse gas (GHG) emissions. To this end, the Office of Sustainability is maintaining a carbon inventory for each year to track GHG emissions and provide information to guide reduction strategies. The primary objectives of this research were: 1. To update UTA’s greenhouse gas emissions inventory …

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 …

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

Electronic Theses and Dissertations, 2020-2023

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 …

Decision Tool For Prioritizing Bridge Repair Or Replacement, Nyoka Amy Florius

Civil Engineering Dissertations - Archive

Bridges are typically damaged/deteriorated due to various factors that require close evaluation to make informed decisions about repair/replacement. There are several aspects of study to evaluate bridges for repair/replacement, such as age, structural adequacy, and frequent usage. Further, bridges which are in poor condition must be identified to mitigate their damage/deterioration and as a result, maintain a safe environment for users. Therefore, to assess the need for funding, state Departments of Transportation are required to evaluate bridges by considering several factors, while prioritizing safety. In Texas, the Highway Bridge Program is responsible for funding bridges which are listed for repair/replacement. …

Improving Probabilistic Quantitative Precipitation Forecasting Using Machine Learning And Statistical Postprocessing Methods, Mohammadvaghef Ghazvinian

Civil Engineering Dissertations - Archive

The objective of this research is to address the limitations inherent in conventional statistical postprocessing schemes to generate probabilistic quantitative precipitation forecasts (PQPFs) and improve postprocessed PQPFs quality through introducing new robust statistical models and machine learning frameworks. This dissertation comprises three main elements. First, a new, two-part scheme for creating PQPFs from single-valued quantitative precipitation forecasts is introduced. This scheme, herein referred to as the Mixed-type Non-Homogenous Regression (MNHR), combines the use of logistic regression for estimating rainfall intermittency, and non-homogeneous regression for estimation of additional parameters of the conditional distribution. The performance of MNHR is evaluated relative to …

The Potential Of Location Data For Contact Tracing And Understanding Individual Mobility During The Covid-19 Pandemic, Marcus Figaro

Electronic Theses and Dissertations, 2020-2023

In this study, we first review contact tracing methods used during the COVID-19 pandemic and provide an analysis of the benefits and drawbacks of different data collection and privacy protection methods. Our findings provide the benefits and drawbacks of using GPS versus Bluetooth for contact tracing, as well as the different data collection and storage methods and their effectiveness in protecting user privacy. We then analyze Twitter data to understand individual mobility behavior and sentiment by using a Natural Language Processing tool on text content of user tweets and Tweet coordinate data. Social media's ability to provide data on location …

Application Of Biochar As Beneficial Additive In Concrete, Temirlan Barissov

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

Biochar is a high-carbon solid material produced via thermal decomposition of organic biomass in a low-oxygen environment. Characterized with high water retention properties and high alkalinity, biochar is generally used for soil amendment and fertilization purposes. This study is intended to explore the feasibility of using biochar as a beneficial additive of the most used manmade material, concrete. Literature review revealed several studies where biochar was successfully implemented as an additive in concrete. The beneficial influence of biochar on the mechanical characteristics of concrete is based on nucleation and densification effects. However, the internal microstructure, porosity and chemical composition of …