Engineering Commons^™

Friction And Texture Evaluation Of Asphalt-Based Binders As Alternatives To Epoxy-Based High-Friction Surface Treatments, Alireza Roshan, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

High-friction surface treatment (HFST) is a safety-focused pavement treatment that restores and maintains pavement friction to reduce road accidents. Traditional epoxy-based HFSTs, while widely used, face challenges such as high costs, potential compatibility issues with the substrate pavement, and long-term durability under specific conditions. This study investigates asphalt-based alternative HFST, which is compatible with various pavement types and cost-effective and versatile solutions for a wider range of pavement applications. Performance and friction testing, including the British pendulum test, British wheel test, and dynamic friction test, were performed to examine the coefficient of friction (COF) before and after polishing with a …

Draft Genome Sequences Of Four Phosphate-Solubilizing Microbes Of The Family Burkholderiaceae Isolated From Tailings From The Former Pea Ridge Mine In Washington County, Mo, Usa, Prince Oppong Amoh, Abiodun E. Idowu, Elizabeth R. Grube, Melanie R. Mormile, Hunter W. Schroer

Biological Sciences Faculty Research & Creative Works

We present draft genome sequences of four Gram-negative phosphate-solubilizing microbes isolated from Pea Ridge Mine tailings in Missouri, USA. Belonging to the family Burkholderiaceae, these isolates exhibit a phosphate-mineral-dissolving phenotype in liquid and solid cultures. Genome sizes span 5.6–9.7 Mb, with GC contents of 61.6%–67.0%.

Digital Solutions For Bridging Language Barriers: Designing And Testing An App For Construction Spanish Safety Communication On Construction Jobsites, Adrian Cappella

All Theses

Language barriers between English-speaking supervisors and Spanish-speaking workers create safety risks on U.S. construction jobsites. Hispanic workers face higher injury and fatality rates, with miscommunication being a major contributing factor. Existing translation tools lack the accuracy, cultural context, and jobsite relevance needed for effective safety communication.

In this study a mobile application with construction-specific safety phrases in English and Spanish was designed and field tested. The research included a literature review, phrase collection and validation with industry experts, application development and design with a computer science collaborator, and usability testing with supervisors and workers. Surveys and field trials measured navigation, …

Steel-Concrete Composite Girder Experiments To Isolate Interface Load Transfer Effects On Stud Fatigue Life, Marc Crespi Hromcova

Graduate Theses and Dissertations

Metal fatigue resulting from repeated loading is a primary limit state that affects the quantity of headed shear studs required in the composite design of steel bridge girders. While concrete-deck-to-steel-superstructure load transfer is only considered through stud bearing in the American Association of State Highway Transportation Officials (AASHTO) design standards, friction and interface interlocking effects may also contribute. This study aims to experimentally quantify the effect of interface conditions on the fatigue life of headed studs within composite girders. In this study, two full-scale composite girder specimens having the same geometry and material properties are tested with two interface conditions. …

Optimizing Indigenous Timber Short-Gap Crossing Designs By Minimizing Wood Moisture Content, Robert Greenwood

Graduate Theses and Dissertations

Reducing moisture content increases wood strength and reduces the weight of timber members. An accurate and efficient method for measuring moisture content is important for the design and construction of indigenous timber short-gap crossings. This study evaluates different methods for measuring moisture content in timber, describes a methodology for developing a representative moisture content value for a timber log, and approaches for quickly drying large timber logs. The results of this thesis will support activities in developing a representative moisture content of a log for structural design purposes and reducing weight for constructability purposes. The approaches discussed were developed considering …

Toward A Better Understanding Of Friction, Adhesion, And Stud Bearing Shear Transfer At The Steel-Concrete Interface Of Composite Bridge Girders, Callie Grace James

Graduate Theses and Dissertations

Following curing of the concrete deck, load transfer between the concrete and steel components in a composite bridge girder is possible through three mechanisms: 1) mechanical contact (bearing) between the embedded shear connectors and surrounding cured concrete, 2) adhesion between the cured concrete and steel-section top flange, and 3) friction between the contacting materials Understanding the mechanisms of bearing, adhesion, and friction shear transfer at the steel-concrete interface of composite bridge girders is necessary for efficient proportioning of headed shear connectors (or studs) in design. To better understand the roles that stud bearing, adhesion, and friction play in composite girder …

Confinement-Dependent Transient Mi For The Hoek-Brown (H-B) Strength Criterion, Hao Li, Leo Pel, Zhenjiang You, David Smeulders

Research outputs 2022 to 2026

The growing global demand for mineral resources necessitates deeper excavation, where increasing in situ stresses pose significant geomechanical challenges. Consequently, an accurate strength assessment of deep-seated rock masses is crucial for ensuring the safety and reliability of underground excavations. The Hoek-Brown (H-B) strength criterion remains a widely applied rock strength criterion. However, its conventional form struggles to characterize the full nonlinear evolution of rock strength from pre-critical to critical conditions across varying confining stresses. To address this limitation, this study proposes a Confinement-dependent Transient mi Model (CTM) as an enhancement to the H-B criterion. By incorporating confinement-sensitive variations of mi, …

Investigating The Correlation And Synergy Of Artificial Intelligence Techniques, Construction Technologies, And Their Key Benefits, Fareed Salih, Islam H. El-Adaway

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Despite its reputation as one of the least digitized sectors, the construction industry increasingly adopts artificial intelligence (AI) and construction technologies. However, previous research has not adequately explored the benefits of AI techniques and construction technologies nor the correlations between them. This study aims to fill this knowledge gap. To this end, the authors used a multistep research methodology. First, a systematic literature review of studies published between 1985 and 2022 was conducted to identify AI techniques and construction technologies. Second, content and frequency analysis were performed to determine the benefits associated with AI and technology adoption. Finally, a survey …

Development Of A Kytc Highway Geometric Design Workshop, Jill Asher, Jeff Jasper, Travis Thompson, Chris Van Dyke

Kentucky Transportation Center Research Report

In-depth knowledge of geometric design principles is a prerequisite for delivering road projects that provide safe and efficient multimodal mobility for all users. Historically, Kentucky Transportation Cabinet (KYTC) early-career design staff arrived at the agency with little design experience. The agency has relied on a combination of short courses and mentorship provided by experienced personnel to bring early-career design staff up to speed on design best practices. However, this approach to training carries limitations. Employee turnover and imposing workloads make it challenging for early- and even mid-career design professionals to receive guidance from seasoned designers who have long tenures at …

Development Of A Handy Tool For The Selection Of Urban Stormwater Best Management Practices, Aaron T. Kenny

Civil & Environmental Engineering Theses & Dissertations

The City of Norfolk, Virginia faces substantial stormwater management challenges due to shallow groundwater, tidal influence, dense urban development, and limited right-of-way. These constraints limit the applicability of many Best Management Practices (BMPs) and require the early identification of feasible practices before detailed hydrologic modeling. This thesis introduces a decision-support tool that quickly and systematically identifies and prioritizes BMPs that are both feasible and well-suited to Norfolk’s Municipal Separate Storm Sewer System (MS4) program, streamlining early-stage selection and saving time and resources.

The tool implements a two-stage methodology. First, feasibility gates are applied using catalog attributes derived from the Virginia …

Enhancing Management Of Transportation Projects: Integration Factors For Using Smart Contracts, Mariam Elazhary, Islam H. El-Adaway

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The US Department of Transportation (USDOT) delivers a wide range of infrastructure projects, backed by a fiscal year 2023 budget exceeding $100 billion. These projects face mounting pressures to meet performance, accountability, and delivery standards, driven by their dependence on public funding and their operational complexity. Transportation infrastructure presents sector-specific challenges - such as time-sensitive user disruptions, multiparty coordination, and asset intersection risks - that demand more robust, automated, and transparent project delivery mechanisms. Blockchain-enabled smart contracts have emerged as a promising solution to address these operational pain points through real-time automation, immutable data records, and decentralized transaction processing. However, …

The Equity Implications Of Pecuniary Externalities On An Electric Grid, Charles Sims, Gasser G. Ali, J. Scott Holladay, Tim Roberson, Chien Fei Chen, Islam H. El-Adaway

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The adoption of rooftop photovoltaic (PV) systems can create upward pressure on retail electricity rates as utilities are forced to spread their fixed costs of generation and transmission across a smaller customer base. Since high-income households are more likely to purchase PV systems, low-income households may be disproportionately impacted by these rate increases. Using a novel combination of agent-based computational economic modeling and a choice experiment of rooftop solar adoption, we show how this pecuniary externality between low- and high-income customers increases low-income electricity bills by 10% in an area with some of the highest poverty rates in the United …

Evaluating Crumb Rubber Modified (Crm) Asphalt As A Sustainable Binder Alternative For High-Friction Surface Treatments, Abdallah Aboelela, Alireza Roshan, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

High-friction surface treatments (HFSTs) are widely applied to improve pavement safety by enhancing long-term skid resistance. Although epoxy resins are commonly used due to their strength and durability, their high cost, susceptibility to delamination, incompatibility with substrates of flexible pavements, and adverse environmental concerns limit their long-term performance. This study presents crumb rubber modified (CRM) asphalt as a sustainable alternative binder for HFST applications. CRM binders offer high performance and compatibility with existing pavement surfaces, cost effectiveness and reduced environmental impacts as compared to epoxy binders. In addition, the binder development utilizes enhanced recycling technologies for interacting with used tire …

Comparison Of The Recent Icrp Occupational Intakes Of Rradionuclides Series To Annual Limits On Intake (Ali) In The United States For Select Radionuclides, Aidan B. Barker

All Theses

Dose coefficients (DCs) and secondary limit values (such as the annual limit on intake [ALI] and derived air concentration [DAC]) are useful and convenient quantities in radiation protection (RP) for estimation of radiological dose and the practical application of dose limits. DCs link radioactivity intake to dose while secondary limit values express a dose limit in terms of the type and extent of exposure. The International Commission on Radiological Protection (ICRP), an international organization which provides guidance and recommendations for RP, calculates, tabulates, and updates DCs following new findings and updated knowledge relevant to dose determination (e.g. improved human biokinetics, …

A Comparative Analysis Of Complete Streets And Multimodal Transport Approaches: Implications For Sustainable Urban Mobility In Lincoln, And Global Contexts, Oliva Richard Kilyenyi

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

Movement of people and goods in urban areas through different modes of transportation including walking, cycling, public transit and by autos is termed as urban mobility. Urban mobility presents significant environmental, social, and economic challenges for cities worldwide as they grapple with the impacts of conventional transportation systems, particularly in North America context where car-centric planning approaches has dominated urban developments since 1950s. Car-centric dominance is 80% in North American Metropolitan areas (Manaugh et al., 2015). The impacts of these conventional systems include greenhouse gas emission emissions contributing approximately 24% of global carbon dioxide (CO₂) emissions, air pollution …

Rapid Construction Of Short Gap Crossings Using Indigenous Timber, Jack Everett Hamburger

Graduate Theses and Dissertations

This thesis examines multiple design options for constructing short span crossings for the military using indigenous timbers. Using indigenous timbers allows for a significant reduction in resources that must be brought into a site for construction. Construction time is minimized by optimizing the steps to convert indigenous timber into structural members for use as timbers in a short gap crossing. A major objective during this thesis study was to examine approaches for maximizing timber strength for design purposes and reduce timber weight for handling purposes. Wood strength and wood weight are highly dependent on moisture content. Decreasing moisture content addresses …

Evaluating Psychosocial Stressors And Mental Well-Being Of Construction Professionals From The Management Standpoint: An Exploratory Study, Md Tauhidul Karim

Masters Theses

Construction professionals face persistent workplace stressors that undermine their mental well-being outcomes. Despite progress in general job-related stressors, social and interpersonal aspects of psychosocial stressors traditionally remain underexplored in the construction management research. The present study examines how social and interpersonal factors influence construction workers’ mental well-being and how management’s awareness, responsiveness, and strategic roles evolved in the transition of the COVID-19 pandemic at the organizational level. An integrative mixed-methods approach was employed, combining a systematic literature review, a bibliometric analysis, and an exploratory case study to capture the current landscape of mental well-being and management standpoints in the US …

Impact Of Equipment Type On Measured Particle Size Of Civil Engineering Materials, Tanner Turben, Tasnimul R. Ferdous, Andrew Braham, Wen Zhang

Civil Engineering Faculty Publications and Presentations

Particle size analysis (PSA) captures the size distribution of finely graded materials with particles generally smaller than 1000 microns. Many civil engineering materials do not leverage PSA for material specifications or acceptance despite the insight into material performance and quality gained through understanding the particle size. The objectives of this study are to compare PSA measurement principles by testing 13 civil engineering materials by laser diffraction, Coulter counter, and microscopy. Asphalt emulsions, cementitious materials, sands, clays, and biological samples were selected to represent a wide set of interests and shapes. It was found that between laser diffraction and Coulter counter …

Accident Data Analytics And Ai-Based Auditory Enhancement For Highway Construction Safety, Thinh Nguyen

All Dissertations

This research develops data-driven and AI-enhanced approaches to improve worker safety in highway construction environments. The study integrates advanced analytics and auditory signal enhancement to identify high-risk worker behaviors and improve real-time safety warnings. The work consists of three core studies. The first study applies Sequential Pattern Mining and Social Network Analysis to more than 1,000 construction accident reports to identify high-risk worker actions and their hidden sequential relationships with accident types and consequences. These insights reveal sector-specific risk patterns, supporting the creation of targeted, data-informed safety interventions. The second study introduces an AI-based auditory enhancement model built on a …

Private Sand Mining In The Mississippi River: Sediment Budget And Morphology Implications Between Baton Rouge And Belle Chasse, Louisiana, Brett Mcmann

LSU New Orleans Theses and Dissertations

This analysis examined how private sand mining within the Mississippi River between Baton Rouge, LA and Belle Chasse, LA affected its sand budget from 2004-2012.

Records assembled indicated that private mining removed an annual average of 2.8 million cubic yards of sand. A HEC-RAS one-dimensional sediment transport model was utilized to assess this practice. Three scenarios were simulated: a baseline without mining, conditions reflecting documented mining rates, and a hypothetical case with excessive extraction.

Results suggest that private mining constituted approximately 26 percent of the total sand deficit between Baton Rouge and Belle Chasse. Mining appeared to cause localized changes …

Intrinsic Disinfection Byproducts In Free Chlorine And Chloramine Systems: Formation Of Chlorite, Chlorate, Perchlorate, And Chloronitramide Anion, Julian L. Fairey, Ashley D. Pifer, David G. Wahman

Civil Engineering Faculty Publications and Presentations

Intrinsic disinfection byproducts are formed by reactions between disinfectant species and/or their decomposition products. In this review, we focus on a subset that accumulates in free chlorine and chloramine drinking water systems. First, we review the sequential formation of chlorite, chlorate, and perchlorate in hypochlorite feedstocks. Model simulations indicate chlorate and perchlorate can accumulate under realistic dosing conditions and can be managed with less concentrated feedstocks and climate-controlled storage. Second, we review the formation pathways of dichloramine and chloronitramide anion. Chloronitramide anion accumulation may be mitigated by increasing monochloramine stability and quenching reactive nitrogen species in its formation pathway.

Using Hydraulic And Hydrologic Modeling To Determine Scour At Toro Creek Under Climate Change Conditions, Gabriel E. Alaniz

Master's Theses

ABSTRACT

This study evaluates bridge scour at the Toro Creek crossing of Highway 1 in Morro Bay, California, under present conditions and future climate conditions with more frequent extreme rainfall events. California infrastructure is becoming increasingly vulnerable to extreme storm events and increased intense precipitation events brought by climate change. This analysis focuses on the calculation of scour for both the northbound and southbound spans. Highway 1 plays a vital role in California’s coastal transportation infrastructure by carrying more than 20,000 vehicles daily (Caltrans, 2017). In this thesis, a hydrological model (HEC-HMS) is used to simulate runoff under present-day and …

Ethical Decision-Making Processes In Authentic Environmental Engineering Contexts Through Systems Thinking And Team Collaboration Lenses: An Embedded Single Case Study, Toluwalase Eniola Brower

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Ethical and professional responsibility is a critical learning outcome emphasized in ABET accreditation. However, ethics instruction in engineering education often lacks integration of system-level considerations such as economic, environmental, and societal contexts, that are essential for developing engineering solutions that ensure the safety and welfare of diverse stakeholders. This embedded single-case study investigated the integration of authentic ethics instruction within a junior-level environmental engineering course at a Midwestern U.S. university during spring 2025 and explores how civil engineering student teams within the course engage in ethical decision-making process during authentic problem-solving.

The instructional intervention consisted of four problem-based ethics modules, …

Rainfall-Runoff Modelling In An Indonesian Humid Tropical Area Using Satellite-Based Precipitation Products, Noordiah Helda

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

This dissertation explores three rainfall-runoff models in the humid tropical regions of Indonesia using satellite-based precipitation products (SBPPs) and develops integrated machine-learning modeling frameworks. Several ground-based observations from BMKG (Badan Meteorologi, Klimatologi, dan Geofisika (also known as the Indonesian Agency for Meteorology, Climatology, and Geophysics)) stations across Indonesia (133−165 stations) are compared and evaluated against satellite products, indicating that GPM performs well, with R-squared values ranging from 0.54 to 0.76 and correlation coefficients ranging from 0.45 to 0.69, respectively.

In the Martapura Watershed, South Kalimantan, due to a lack of observational discharge data, streamflow was generated using the FJ Mock …

Large-Scale Experimental Study On The Impact Of Air Cleaning & Ventilation On Indoor Air Quality And Student Illness-Related Absenteeism, Daud Nosham

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

This large-scale randomized experimental field study investigated the effect of portable air purifiers (PAPs) on classroom’s air quality and student’s illness related absenteeism. PAPs were installed in 317 classrooms from various school districts located in Eastern Nebraska. The classrooms were randomly assigned into four conditions: three treatment conditions (T1, T2 & T3) and one control condition (device without any filter). T1 was equipped with HEPA filters, T2 added Activated Carbon (AC) layer to HEPA, and T3 further integrated Germicidal Ultraviolet (GUV) alongside HEPA and AC filters. The measured variables were carbon dioxide (CO2), fine particles (PN2.5) and coarse particles (PNcoarse), …

Mbse For Process Analytical Technology- Bwon Analysis Case Study, Arnaldo Garcia Cervantes

Open Access Theses & Dissertations

Volatile Organic Compound (VOC) emissions from industrial sources, particularly Benzene, present significant environmental and public health challenges. Regulatory frameworks, such as the U.S. Environmental Protection Agency’s Benzene Waste Operations NESHAP (BWON), mandate strict monitoring of control devices, specifically carbon adsorption canisters, to prevent emission breakthrough. However, current industry practices rely heavily on manual Method 21 testing, a labor-intensive process that creates lagging indicators and increases the risk of non-compliance events. This thesis proposes the design and development of an on-line, automated fugitive emissions monitoring system tailored for carbon canisters using Model-Based Systems Engineering (MBSE). Utilizing the Object-Oriented System Engineering Method …

Calibration Of Low-Cost Pm2.5 Sensors Using Data Continuously Generated At A Reference Station In El Paso, Texas, Brenda Lizbeth Hernandez

Open Access Theses & Dissertations

Low-cost sensors (LCS) offer a cost-effective way to expand air-quality monitoring networks, but they require strong calibration methods to ensure reliable performance under changing environmental conditions. In this study, Clarity LCSs were co-located with a state reference monitor for 6 months to evaluate fixed-time (2-, 3-, 4-, and 6-week) and rolling (2- and 3-week) calibration approaches. A multivariate regression model using PM1, PM2.5, PM10, and relative humidity was used to generate calibration coefficients for a “base sensor.” Data from two additional sensors were normalized to the base unit using linear regression, and their calibration coefficients were applied across the network. …

Investigation Of Hot Mix Asphalt Aging Effect On Binder Performance, Zahra Mohajeri

Open Access Theses & Dissertations

Asphalt roads continuously experience physicochemical changes under the combined influence of oxygen, heat, ultraviolet (UV) radiation, and water. Oxidation increases molecular polarity and association, causes maltenes loss, and continues hardening the asphalt binder, reducing ductility, stress-relaxation capacity, and resistance to cracking (Petersen 1982; Colbert and You 2012). Because aging is a cumulative process beginning at plant production, accelerating during construction/compacting, and continuing in service, the laboratory tests and indices must capture the extent of short-and long-term aging to support performance-related specification and Balanced Mix Design (BMD) (AASHTO R30 2022; Kim et al. 2017). This chapter reviews: (i) laboratory and field-representative …

Concrete Masonry Unit Construction: Creating Educational Modules On Sustainability, Eric Dam

Construction Management

Concrete Masonry Units are one of the most widely used building materials due to their durability, fire resistance, low maintenance, and specifications. With the growing trend for sustainable construction, it is necessary to teach students how CMUs can contribute to improving environmental performance and dive deeper into multiple resource efficiency. This project developed an instructional module that introduces CMU materials, reviews performance and durability attributes of these materials, and how they are linked to well-known rating systems. The final module includes a presentation, three assignments, and one quiz that will reinforce student learning and refresh industry professionals' knowledge. The following …

Life Cycle Assessment Of A Prefabricated Modular Timber Building, Bryan Mai

Construction Management

Traditional concrete construction carries a high carbon footprint, motivating interest in lower-impact alternatives such as prefabricated modular timber systems. This project conducts a process-based life cycle assessment (LCA) using OpenLCA to evaluate the environmental impacts of a modular timber building. Material quantities from major processes were modeled as flow inputs and converted into standardized OpenLCA units. Impact categories—including acidification potential, human toxicity, and energy/resource use—were analyzed to determine which materials and processes contribute most to overall environmental burden. Results show that transportation and plumbing materials drive the largest acidification impacts, while interior finishes dominate human toxicity. This LCA establishes a …