Civil and Environmental Engineering Commons^™

Covid-19 And Traffic Safety: Exploring Exposure, Crash Frequency And Severity, And Roadway And Network Design, Nicholas N. Ferenchak Ph.D

Publications

Early COVID-19 lockdowns in the first half of 2020 largely kept people at home, thereby reducing motor vehicle traffic levels. Theoretically, reduced traffic exposure should have resulted in reduced motor vehicle crashes. However, a variety of factors may have complicated this relationship. In order to better understand the impact of COVID-19 lockdowns on traffic safety outcomes, we explore fatalities, injuries, and total crashes before and during the lockdowns on both the national and state levels. We provide descriptive statistics and create negative binomial regressions exploring the role of vehicle, user, and built environment factors on traffic safety outcomes. Findings suggest …

Covid-19 And Traffic Safety: Exploring Exposure, Crash Frequency And Severity, And Roadway And Network Design, Nicholas N. Ferenchak Ph.D

Data

Early COVID-19 lockdowns in the first half of 2020 largely kept people at home, thereby reducing motor vehicle traffic levels. Theoretically, reduced traffic exposure should have resulted in reduced motor vehicle crashes. However, a variety of factors may have complicated this relationship. In order to better understand the impact of COVID-19 lockdowns on traffic safety outcomes, we explore fatalities, injuries, and total crashes before and during the lockdowns on both the national and state levels. We provide descriptive statistics and create negative binomial regressions exploring the role of vehicle, user, and built environment factors on traffic safety outcomes. Findings suggest …

Increasing Bridge Durability And Service Life With Lidar Enhanced Unmanned Aerial Systems (Uas), Fernando Moreu, Mahsa Sanei, Chris Lippitt

Publications

Bridge construction inspections require quantitative measurements and location information. The conventional approach is visual inspection, which in general, is rather time-consuming, expensive due to traffic closure, subjective, and needs special access. Therefore an automated rebar layout detection algorithm was developed to quickly extract quantitative rebar layout information from the LiDAR data. This systematic method can automatically cluster the bridge elements from a 3D point cloud by using LiDAR-equipped UAS data collection and unsupervised machine learning techniques. A new automated inspection system using a LIDAR-equipped UAS can eventually if developed and tested be more reliable as well as less expensive. In …

Development Of Balanced Mix Design Quality Control Specifications Based On The Acceptance Limits Of Hma Performance Tests, Lucas Tameirao Abrantes

Open Access Theses & Dissertations

With the augmented use of recycled materials, recycling agents, modified binders, andwarm mix asphalt additives, several highway agencies including the Texas Department of Transportation (TxDOT), have considered methods to improve the durability and long-term performance of asphalt concrete (AC) mixes. The need for performance tests that could consistently evaluate the rutting and cracking potentials of AC mixes became crucial as the popularity of the Balanced Mix Design (BMD) concept has increased over the years. A concern now is related to the practicality of these tests for routine use in the process of quality control and quality assurance during the field …

Krs And Kar Review Of Models As A Legal Contract Document, Bryan Gibson, Pam Clay-Young, Rachel Catchings, Chris Van Dyke

Kentucky Transportation Center Research Report

State departments of transportation (DOTs) are expanding the use of electronic engineering data (EED) throughout highway projects — from design and construction through asset management. Included under the umbrella of EED are technologies such as building information modelling (BIM), digital terrain models (DTMs), and 3D models and plan sets. The Kentucky Transportation Cabinet’s (KYTC) Digital Project Delivery (DPD) Initiative is spearheading the transition to EED in the state. While digital delivery promises to streamline project development and management it does not come without hurdles. This report discusses methods for agency wide implementation of EED and highlights best practices for managing, …

An Evaluation Of Energy Consumption Comparing Conventional Water Treatment Plants To Microfiltration And Ultrafiltration Water Treatment Plants, Danielle Larsen

All Theses

The use of low-pressure, hollow fiber microfiltration (MF) and ultrafiltration (UF) membranes has become increasingly prominent in drinking water treatment plant configurations over the past 30 years. At the same time, the topics of energy efficiency and sustainability in industry are becoming progressively more important. Although MF and UF are highly successful in filtration, they are generally thought of as significant energy consumers; however, the data have not yet been available to compare multiple plants in various contexts to determine the factors that most affect energy use. This research compares the energy use of MF and UF treatment plants to …

Rapidly Deployable Structures For Disaster Relief And Military Use, Jayson Leonard

All Theses

Rapidly deployable structures currently play a vital role in the recovery aspect of disaster-stricken areas and the safety of military personnel in hostile zones. More recently there has also been a need for the structures to deal with unforeseen disruptions caused by the COVID pandemic, such as COVID testing centers or backyard pop-up offices. These structures could be used in different environments and serve many other purposes. Along with the structural performance of these shelters, they need to integrate into systems set in place effortlessly. For that reason, four key factors were taken into consideration, namely (1) deployability (how difficult …

The Evacuation Simulation Of Wheelchair Users In A Building Fire: An Initial Dynamic Characterization Of Structural Egress Components, Haley Hostetter

All Theses

People with disabilities are one of the most vulnerable groups involved in building fires. According to the U.S. Fire Administration, in the United States alone, an estimated 700 home fires involve people with physical disabilities each year while over 1700 involve those with mental health disorders. Despite this, the current body of literature shows few studies focused on the evacuation of disabled people. This is a direct result of past and present social injustice on people with disabilities and has resulted in high injury and death rates during fires. To combat this, enrich the literature, and improve their experiences in …

Compound Flooding In Convergent Estuaries: Insights From An Analytical Model, Ramin Familkhalili, Stefan Talke, David A. Jay

Civil & Environmental Engineering Faculty Publications

We investigate here the effects of geometric properties (channel depth and cross-sectional convergence length), storm surge characteristics, friction, and river flow on the spatial and temporal variability of compound flooding along an idealized, meso-tidal coastal-plain estuary. An analytical model is developed that includes exponentially convergent geometry, tidal forcing, constant river flow, and a representation of storm surge as a combination of two sinusoidal waves. Nonlinear bed friction is treated using Chebyshev polynomials and trigonometric functions, and a multi-segment approach is used to increase accuracy. Model results show that river discharge increases the damping of surge amplitudes in an estuary, while …

Quantifying The Workability Of Calcium Sulfoaluminate Cement Paste Using Time-Dependent Rheology, Sukanta K. Mondal, Adam Welz, Carrie Clinton, Kamal Khayat, Aditya Kumar, Monday Uchenna Okoronkwo

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Poor workability is a common feature of calcium sulfoaluminate (CSA) cement paste. Multiple chemical admixtures, such as set retarders and dispersants, are frequently employed to improve the workability and delay the setting of CSA cement paste. A quantitative assessment of the compatibility, efficiency, and the effects of the admixtures on cement paste workability is critical for the design of an appropriate paste formulation and admixture proportioning. Very limited studies are available on the quantitative rheology-based method for evaluating the workability of calcium sulfoaluminate cement pastes. This study presents a novel and robust time-dependent rheological method for quantifying the workability of …

Inspection Of Flexible Fillers In Post-Tensioned Bridges, Carley Gonzalez

Doctoral Dissertations and Master's Theses

The Florida Department of Transportation (FDOT) is currently pushing toward the use of flexible fillers (FF) in new post-tensioned (PT) bridges. Flexible fillers have several advantages compared to the currently used cementitious grouts (CG) and can offer longer-lasting structures by providing better corrosion protection and allowing for replaceable tendons, which reduces the overall maintenance costs over the structure’s lifespan. Due to these fillers being used in new bridges, FDOT needs effective nondestructive evaluation (NDE) methods to employ in their biennial inspections. There are currently numerous NDE methods available to inspectors that have been used to identify defects in PT bridges …

A Snapshot Of Sars-Cov-2 In Wastewater Treatment Plants In Northwest Arkansas, Katie Loethen

Biological and Agricultural Engineering Undergraduate Honors Theses

Because SARS-CoV-2, a coronavirus, is released in the fecal shedding of covid-positive patients, the virus enters the municipal waste stream and flows to wastewater treatment plants (WWTPs). The goal of this research is to quantify the effectiveness of wastewater treatment processes at removing SARS-CoV-2 from wastewater and preventing its release into the environment. Sampling at Paul R. Noland and West Side WWTPs in Fayetteville, Arkansas, took place from August 2020 to May 2021, and samples were tested for the presence of SARS-CoV-2 using N1 and N2 primers via RT-qPCR. Sampling days which returned positive detection of one or both of …

Developing A Lagrangian Sediment Transport Model For Natural Streams, Saman Baharvand

Civil Engineering Dissertations - Archive

Sediment transport in natural streams is a complex process that can significantly affect the stream’s water quality, ecosystem, and morphology. Suspended sediment concentrations can adversely affect the health of the ecosystem and aquatic species, and the deposited sediment particles can change the morphology and have irreparable environmental impacts. Several numerical models that can be used to manage and mitigate the adverse effects of sediment released into rivers by natural or anthropogenic activities have been developed to estimate the sediment and pollutant transport in waterbodies. However, the goal of the research for this thesis was to develop a Lagrangian stochastic sediment …

Evaluation Of Decision-Making Prediction Models For Sewer Pipes Asset Management, Salar Shirkhanloo

Civil Engineering Dissertations - Archive

Wastewater collection systems deteriorate over time, requiring continuous adjustments and the development of asset management frameworks on the part of utility owners to maintain the performance of their assets. Any asset management framework should emphasize the importance of asset inspection and condition evaluation for efficient system operation and maintenance. Closed-circuit television (CCTV) is the most widely used tool in the United States for inspecting the interior of sewer pipes, which is a somewhat expensive and time-consuming process given the extensive inventory of pipes in a city. Due to their vast inventory of these pipes, no municipality can inspect every individual …

Implementation Of Secondary And Tertiary Treated Wastewater In Concrete Manufacturing, Amany G. Micheal Prof., Haidy Abdel Salam, Gouda Ghanem

Civil Engineering

Water scarcity is a problem that faces many regions. In a developing and arid country like Egypt, the need for freshwater is exponentially increasing. This research is an evaluation of the recycled wastewater to be used in concrete manufacturing. The treated wastewater is blended with potable water with percentages of 25%, 50%, and 100%. The mixture of the two types of water is used in concrete mixing and curing. Control specimens with pure potable water are cast for comparison. The setting time for Ordinary Portland Cement is tested using the different water mixes. The hardened concrete is tested in compression …

Utilizing Prefabrication In Order To Achieve Leed Credits, Phillip E. Waldman

Construction Management

This paper is a dissertation on the concept and benefits of utilizing panelization in construction to achieve LEED credits. Panelization is the process of prefabricating construction framing materials, such as walls, floors, and roof systems, to streamline and improve the construction process. This dissertation aims to examine: (1) how prefabrication can optimize construction through effective waste management (2) how prefabrication manufacturing plants are more efficient, cost-effective, and better for the environment with regard to material use and recycling than traditional construction methods (3) how prefabrication can be used to obtain LEED credit points for the Construction and Demolition Waste Management …

A Comparable Analysis Of Civilian And Military Airfield Runway Design Procedures, Jacob Wessel

Open Access Theses & Dissertations

In the United States there are two primary agencies that regulate, approve, and aid in airfield runway designs. These two agencies are the Federal Aviation Administration (FAA) and the Department of Defense (DOD), and they both have different design procedure for design and construction of their prospective airfield runways. It is important to have a closer look at the design procedures, the reliance of software and how these compare to each other. The primary objective of this research was to conduct a sensitivity analysis of the FAA and the DOD airfield design programs used to aid in the design of …

Typical Demolition Waste Of Tenant Improvement Projects: A Case Study, Gregory K. Jameson

Construction Management

Sustainable approaches to the waste generated in construction demolition have been on the rise over the past two decades. In this case study research project, the demolition waste of commercial tenant improvement projects from two separate companies across multiple projects was documented and analyzed. This case study was inspired by a motivation to gain a better understanding of what waste is typical in tenant improvement remodels, what is being done to repurpose this waste and what obstacles currently stand in the way of better waste management practices. After conducting extensive research and analysis of current waste trends in the construction …

Study And Comparison Of The Performance Of Steel Frames With Brb And Sma Bracing, Mohsen Jalalvandi, Ahmad Soraghi, Seyed Mohammadreza Farooghi Mehr, Abbas Haghollahi, Ali Abasi

Department of Civil and Environmental Engineering: Faculty Publications

Designing steel structures with Concentric Braced Frame (CBF) lateral systems has been common in recent decades. This type of bracing has a quite unstable and complicated behavior in relatively intense earthquakes. This study tries to improve the seismic behavior of steel frames with CBF braces equipped with Shape Memory Alloy (SMA) and Buckling Restrained Braces (BRBs). In this manner, a multi-story building with inverted V chevron bracing was considered. Nonlinear time-history analyses have been performed using OpenSEES software. The dynamic responses of frames with SMA and BRB braces were compared. The results showed that the SMA and BRB braces provide …

Towards Sustainable Cities: Life Cycle Cost Analysis Of The Construction Of A Novel Wastewater Management System, Bibhas B. Tanmoy

Theses and Dissertations

Wastage of water is one of the most common environmental issues in the modern era. However, if this level of usage can be controlled, or recirculated properly, the wastage can be lowered down to a very minimum. In the conventional residential plumbing system, blackwater and greywater gets mixed and goes through the same sewage pipe. This mixture turns the whole wastewater amount into blackwater, which requires complex treatment before discharge. Greywater on the other hand can be discharged to waterbodies requiring almost zero treatment. In this study, a new wastewater management method is proposed where the plumbing system is split …

Tree Ring Reconstructions Of Streamflow For The Lower Rio Grande Valley Of Texas, Adedolapo Mutiyat Adeyanju

Theses and Dissertations

The Rio Grande River is a major water source for people living within the USA-Mexico border. The Rio Grande River has its headwaters in the San Juan Mountains in Colorado and the Sierra Madre Occidental in Mexico before flowing into Texas through El-Paso. The water supply issues facing the Lower Rio Grande Basin (LRGB) are extremely complex from international restrictions to severe climate change. The river shares its flow between the U.S.A and Mexico based on the provisions of the 1944 treaty between the U.S.A and Mexico. The LRGB flow is regulated by releases from Falcon and Amistad Reservoirs managed …

Tap Water Disinfection In The Electrochemical Precipitation Process By Using Novel Conductive Concrete, Md Shoriful Islam

Theses and Dissertations

Electrochemical precipitation (EP) is tested to learn about its impact on disinfectants in tap water. The EP process involves applying electricity through electrodes submerged in water to precipitate dissolved metals like water hardness out without chemical additives. In the study, tap water was tested to learn about EP’s impact on disinfectants. Tap water contains not only hardness but also residual disinfectants. It is very essential for the safety of drinking water against the potential ingress of pathogens before the water reaches the end-users. USEPA mandates that the free chlorine level in drinking water should be 0.2mg/L to 4 mg/L. …

Effectiveness Assessment Of E-Ticketing Technology In Construction Of Transportation Projects, Sharareh Kermanshachi, Karthik Subramanya

Publications

The construction of highway infrastructure has devoted significant resources towards e-Construction to reduce the paperwork and automate the tasks in daily operations. Electronic Ticketing (e-Ticketing) is one such component of e-Construction that aids in the digital transfer of material tickets such as asphalt and concrete which accounts for more than fifty per cent of construction costs. Despite the benefits of e-Ticketing, many state departments and agencies are unwilling to transition into this technology. No studies have identified the cause of the delay in the implementation process, developed a framework to comprehend the platform's full potential, quantified savings, and suggested strategies …

Airborne Contaminant Dispersal In Critical Built Environments, Arup Bhattacharya

All Dissertations

The Indoor Air Quality (IAQ), being one of the most significant exposures to human beings, encompasses the concepts of comfort and safety from unwanted contaminants. Whereas the thermal comfort is controlled through proper conditioning and distribution of ventilated air, controlling the airborne contaminants requires careful investigation of the flow characteristics. IAQ translates to different requirements, depending on the intended use of the indoor environment. In critical indoor spaces such as Operating Rooms and Cleanrooms, the principal focus of IAQ is to remove/contain/divert contaminants flowing with the airstream to maintain the required sterility, as contamination can lead to adverse patient/product outcomes. …

Use Of A Trial Function Method To Semi-Analytically Simulate Matrix Diffusion In Heterogeneous And Fractured Media, Kien Trung Pham

All Dissertations

A semi-analytic trial function model is applied to simulate matrix diffusion in systems of parallel fractures, 2-D/3-D discrete fracture networks, and in 3-D heterogeneous media. The trial function model gives low normalized root mean square error (NRMSE) when compared to the parallel fracture analytical solution over a range of fracture spacing, with considerations for retardation and decay. The semi-analytic trial function model is efficient in time and maintains less than 6% NRMSE when it simulates matrix diffusive transport in 2-D/3-D discrete fracture networks (DFN). The model can predict DFN plume within a few meters of accuracy compared to fine-grid DFN …

Influence Of Specimen Geometry And Anisotropy On Dynamic Modulus Of Asphalt Mixes In South Carolina, Srinivasan Nagarajan

All Dissertations

The objective of this study was to characterize the variability of dynamic modulus of asphalt mixes in South Carolina on the basis of geometry and anisotropy. High priority mixes Surface Type B, and C; Intermediate Type B and C and Base Type A from three different days of production were collected from seven different contractors each having a different aggregate source and the dynamic modulus was measured using the Asphalt Mixture Performance Tester (AMPT) at temperatures of 40, 70, 100 and 130℉ (4.4, 21.1, 37.8, and 54.4℃) and at frequencies of 25, 10, 5, 1, 0.5, and 0.1 Hz. One-way …

Integration Of Techno-Economic Analysis (Tea) And Life Cycle Assessment (Lca) For Sustainable Process Design, Roksana Mahmud

All Dissertations

For sustainable design, technology developers need to consider not only technical and economic aspects but also potential environmental impacts while developing new technologies. Techno-economic analysis (TEA) evaluates the technical performance and economic feasibility of a technology. Life cycle assessment (LCA) evaluates the potential environmental impacts associated with a product system throughout its life cycle from raw material extraction to disposal. Generally, TEA and LCA are performed separately for technology assessment. Understanding of the trade-off between economic and environmental performances is crucial for sustainable process design, which is not fully available if TEA and LCA is performed separately. In contrast, integration …

Tessellated Structural-Architectural Systems: Experimental Testing And Interdisciplinary Student Projects, Grace F. Crocker

All Dissertations

This dissertation discusses a new structural system called a Tessellated Structural-Architectural (TeSA) system. These TeSA systems utilize architecturally appealing tessellations in load-bearing structures comprised of interlocking tiles in a pattern. This dissertation focuses on the design, construction, and structural behavior of these TeSA systems, as well as their value as an interdisciplinary learning tool.

This dissertation has 4 research objectives: 1) Demonstrate the fabrication and construction of a precast reinforced concrete (RC) TeSA shear wall system; 2) Measure the structural performance of the RC TeSA shear wall system; 3) Compare simplified shear and flexural analysis methods for RC TeSA shear …

Development Of Distress Index Prediction Models For Rehabilitation Treatments In Louisiana Using Advanced Machine Learning Techniques, Momen R. Mousa, Marwa Hassan

Publications

Performance prediction models are used by state agencies to predict future trends in distress indices, hence, determining the required maintenance and/or rehabilitation treatment as well as the deterioration rate and remaining pavement service life. However, most of these models are based on a limited number of parameters and cannot predict the performance distress indices reliably. Such limitation resulted in having, most of the time, a maximum prediction period of five years. As a solution and coping with the ever-increasing size of pavement data, machine learning techniques have become a promising alternative. The objective of this study was to develop a …

Using Rice Husk Ash (Rha) As Stabilizing Agent For Problematic Subgrade Soils And Embankments, Zahid Hossain, Rifat Bulut, Fares Tarhuni, Hussein Al-Dakheeli

Publications

Arkansas produces the most of the rice in the United States. About 20% of poddy is rice husk (RH), which is burnt under controlled conditions to produce rice rusk ash (RHA). The RHA is considered an environmental hazard and a significant challenge for rice millers. However, RHA is rich in pozzolanic material, which is mainly silica. In this study, RHA is used to stabilize poor soils. Another commonly used stabilizer, hydrated lime (HL), has also been evaluated for comparison purposes. Thus, this study aimed to determine the optimum percentages of RHA, HL, or a combination of these two agents by …