Engineering Commons^™

Moisture-Induced Degradation And Mechanical Durability Of Mineral-Filled Polylactide (Pla) Composites, Barbara Szaraniec, Aleksandra Ptaszkowska, Alicja Rapacz-Kmita

Journal of Sustainable Construction Materials and Technologies

This study investigates the influence of mineral fillers on the hydrolytic stability and mechanical durability of polylactide (PLA) composites under accelerated aqueous ageing conditions. Composites containing halloysite nanotubes (HNT) and bentonite-based fillers (BM, BS, BSP) at 2 wt.% were prepared using a powder-coating and injection moulding approach. Accelerated hydrolytic degradation was conducted at 50 °C for up to six weeks. The degradation behaviour was evaluated through mass variation, water absorption, incubation medium analysis (pH and electrical conductivity), mechanical testing, surface observations, and contact angle measurements. The results revealed a clear filler-dependent response. Bentonite-filled composites exhibited increased water absorption and accelerated …

Methylglyoxal And Glyoxal In High-Puff Disposable Electronic Cigarette Liquids: Unexpected Accumulation And Enhanced Cytotoxicity, Esther E. Omaiye, Wentai Luo, Kevin J. Mcwhirter, Man Wong, Prue Talbot

Civil and Environmental Engineering Faculty Publications and Presentations

Despite concerns regarding the potential health risks associated with EC use, their design, puff count, and e-liquid formulations have continued to evolve. Aldehydes are a key class of thermal degradation byproducts generated during the vaporization of EC fluids. This study tested the hypothesis that aldehyde concentrations would be elevated in used ECs with high puff numbers. Devices from multiple brands were analyzed to assess the impact of extended use on aldehyde formation. E-fluids were extracted from field-collected and user-donated devices and analyzed using gas chromatography/mass spectrometry to quantify 178 flavor chemicals, two synthetic coolants, nicotine, solvents, and aldehydes (methylglyoxal (MGO), …

The Impact Of Using Microencapsulated Phase Change Materials In Asphalt Binder And Mixtures, Ayyaz Fareed

Theses and Dissertations

Asphalt concrete is a widely used paving material for roadway construction; however, pavement distresses such as thermal cracking (non-load associated), fatigue cracking (load-associated), and rutting (permanent deformation) continue to challenge the performance and longevity of flexible pavements. These issues diminish ride quality, reduce service life, and contribute to increased maintenance needs. Several modifiers, including polymers and fibers, have been used to mitigate pavement deterioration, yet improving the thermal response of asphalt mixtures remains a significant concern, particularly in climates with substantial temperature fluctuations. Microencapsulated Phase Change Materials (MPCMs) have recently emerged as a promising solution due to their ability to …

Applications Of Geosynthetics In Tunnels Construction: A Sustainable Approach To Carbon Footprint Reduction, Ibraheem Rais, Abdullah H. Alsabhan, Md. Rehan Sadique, Shamshad Alam

Journal of Sustainable Construction Materials and Technologies

The use of geosynthetics has transformed tunnelling practices by enhancing structural integrity, durability, and environmental sustainability. This review adopts a systematic literature review design, covering publications from 2000 to 2025 sourced from Scopus, Web of Science, ScienceDirect, and Google Scholar. The selected studies were screened based on relevance, quality, and focus on tunnelling applications, then thematically analyzed into four domains: geosynthetic types, applications, sustainability, and performance evaluation. This review focuses on the applications of various geosynthetics, including geotextiles, geogrids, geocomposites, geocells, and geomembranes, in tunnelling projects. These materials play crucial roles in reinforcing tunnel walls and slopes, improving load distribution, …

Investigation Of Portland Limestone Cement Blended With Biochar From Downdraft Gasification: Hydration Kinetics, Microstructure, Rheology, And Performance Mechanisms, Ugochukwu Ewuzie, Paul C. Ani, Abdulkareem O. Yusuf, Joseph D. Smith, Monday Uchenna Okoronkwo

Chemical and Biochemical Engineering Faculty Research & Creative Works

The widespread adoption of Portland Limestone Cement (PLC) in U.S. concrete production has necessitated research into commercially available supplementary cementitious materials (SCMs) for formulating high-performance, low-carbon blended binders with PLC. This study investigated the influence of biochar (BC) in biochar-PLC composites (CBCs), focusing on hydration kinetics, microstructure, rheology, pore-solution chemistry, compressive strength, and the underlying mechanisms. Biochar was produced via downdraft gasification at 850 °C and incorporated into PLC at 5, 7, and 10% substitution by mass. Isothermal calorimetry and hydration data modeled using the Knudsen equation revealed that BC retarded early hydration but improved hydration degree and later-age heat …

The Shrinking Caspian Sea: Eco‐Hydrological Responses To Human And Climate Pressures, Jesse Duku, Mohammad J. Tourian, Marzi Azarderakhsh, Rovshan Abbasov, Ali Mehran, Ali Torabi Haghighi, Stefanos Xenarios, Azara Boschee, Salih Babagiray, Mojtaba Sadegh, Nima Shokri, Ali Nazemi, Alireza Farahmand, Samaneh Ashraf, Temur Khujanazarov, Elmira Hassanzadeh, Dalal Najib, Daniel Placht, Shamshagul Mashtayeva, Ekaterina Rets, Hamid Norouzi, Kaveh Madani, Manoochehr Shirzaei, Hossein Shafizadeh-Moghadam, Chiyuan Miao, Ali Mirchi, Shuo Wang, Amir Aghakouchak

Publications and Research

The Caspian Sea, the Earth's largest inland water body, faces water level decline, drawing comparisons to the collapse of the Aral Sea. Unlike the Aral Sea, the relative roles of climatic variability, hydrological changes, and anthropogenic pressures on the Caspian Sea remain poorly understood. Here, we integrate satellite observations, in situ hydrological records and reanalysis data to examine recent drivers of the Caspian water loss. We show that total river inflow to the Caspian Sea has declined significantly, primarily due to reduced discharge from the Volga River. At the same time, precipitation over the basin has remained broadly stable, while …

Numerical Assessment On The Use Of Structured Coral Reefs To Mitigate Tsunamis, Rim Ahmed Alsheikh Ali

Thesis/ Dissertation Defenses

This thesis investigates the role of coral reefs as nature-based tsunami protection systems for coastlines in the United Arab Emirates (UAE). The study is significant because the UAE is located near the seismically active Makran Subduction Zone in the Arabian Sea, which may generate tsunami hazards. The research provides a quantitative assessment of how coral reef morphology, particularly reef width and depth, influences tsunami wave attenuation, flow velocity, flow depth, roughness, and bed shear stress.

The study used a multi-phase methodology combining literature review, laboratory experiments, and numerical modelling. Flume experiments were conducted at UAEU using high-fidelity 3D-printed Acropora coral …

Recent Advances In The Rheological Properties Of Ultra-High-Performance Concrete: A Critical Review, Le Teng, Kamal H. Khayat, Jiaping Liu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Ultra-high-performance concrete (UHPC) with adapted rheology continues to attract interest considering the requirement for novel processing techniques such as self-consolidating, pumping, spraying, and three-dimensional (3D) printing. The rheology of UHPC is complex due to its high solid volume fraction, low water content, and wide range of constituent materials that affect its flow properties. This work provides guidance for tailoring the mixture proportioning of UHPC to secure proper rheological properties and performance of UHPC for various applications. In the first part of this work, key physical, physicochemical, and chemical factors that can affect the rheological properties of UHPC are discussed. Rheological …

A Workflow For Automating Geospatial And Data Visualizations For Post-Earthquake Building Damage Data, Alejandra Bravo

Architectural Engineering: Graduate Reports

After major seismic events, reconnaissance efforts of various types are made to gather data. Coarse data can be collected with satellite imagery, mid-scale data can be recorded by capturing thousands of images, and granular data is typically documented manually by humans. Post-earthquake reconnaissance teams can be deployed by universities, research organizations, professional associations, and private firms. Academics, engineers, and students with varying degrees of expertise are tasked with collecting building metadata and damage data, typically in a short period of time. This data can be of various types including numerical (i.e. number of stories, height, etc.), categorical (i.e. damage level, …

An Exploratory Latent Segmentation Approach To Account For Temporally Shifting Parameters In Driver Injury-Severity Models, Tanmoy Bhowmik, Shahrior Pervaz, Fred Mannering, Naveen Eluru

Civil and Environmental Engineering Faculty Publications and Presentations

Temporally shifting parameters in crash severity modeling is a well-documented phenomenon, with growing evidence suggesting that the influence of explanatory variables changes over time due to shifts in driver behavior, vehicle technology, and roadway conditions. Many studies have examined this issue by comparing the temporal stability of adjacent-year data using a variety of modeling frameworks that have often assumed a homogenous effect of explanatory variables across the entire crash population. The current research effort departs from past work in two ways. First, it compares data separated by multiple years (instead of comparing adjacent years), and second, it tests the homogeneous …

Airline Strategy Research: A Bibliometric And Thematic Analysis (1980–2025), Mustafa Kaya, Tuba Bayar, Renan De Oliveira, Gui Lohmann, Ferhan K. Sengur

Research outputs 2022 to 2026

Research on strategic management in airlines has rapidly expanded since its inception in the 1980s, with studies providing valuable insights into topics such as alliances, competitiveness, sustainability, and digitalisation. To contribute to this effort, the present study presents an integrative bibliometric analysis of 306 documents indexed in either the Web of Science or Scopus (1980–2025). Using Bibliometrix (R), a performance analysis indicated that although this research topic shows steady growth, its citation impact is concentrated among a limited number of authors, institutions, and specialist journals. Competitive advantage, service quality, alliances, low-cost airlines, financial performance, business strategy, revenue management, and pricing …

Enhancing Urban Refueling Efficiency: Strategies For Sustainable Mobility And Economic Impact, Navid Hashemi Taba, Iftekhar Ahmad, Ahdieh Sadat Khatavakhotan

Research outputs 2022 to 2026

In response to increasing concerns about operational inefficiencies and environmental impacts at petrol stations, this operational research investigates strategies to enhance refueling efficiency across 103 stations in Perth. A pilot study employing observational methods and time-motion analysis established ideal benchmarks for core refueling activities. Empirical analysis of driver behavior during high-demand periods—often driven by fuel price discounts—and regular off-peak hours revealed significant performance gaps, highlighting substantial opportunities for efficiency improvements. Eliminating non-essential tasks could yield time savings of up to 67% during peak periods and 45% during off-peak periods. Economic analysis demonstrated mutual benefits when refueling processes align with these …

A Hybrid Mechano-Thermal Route To Synthesize Reactive Pozzolans From Clay Minerals: A Case Of Kaolinite, Oluwadamilare Charles Adesina, Bryan K. Aylas-Paredes, Brian R. Cherry, Luciano A. Gobbo, Aditya Kumar, Narayanan Neithalath

Materials Science and Engineering Faculty Research & Creative Works

Aluminosilicate resources from unconventional sources offer promising potential for developing low-carbon supplementary cementitious materials (SCMs), yet their activation typically requires energy-intensive thermal processing. Kaolinite is a geographically abundant and highly attractive precursor clay mineral to reduce the clinker factor in concrete. By integrating mechano- and thermo- chemistry sequentially in a novel hybrid mechano-thermal activation (MTA) strategy for clay mineral activation, the dehydroxylation of pure kaolinite polymorphs KGa-1b and KGa-2 for enhanced pozzolanic reactivity is unlocked at temperatures that are lower than those needed for conventional thermal activation (TA). The mechano-chemical activation (MCA) step that induces significant structural defects and disorder …

Recycling Aged Crumb Rubber-Modified Asphalt Pavements: A Review, Kwadwo Ampadu Boateng, Meng Wu, Dongzhao Jin, Zhanping You

Michigan Tech Publications

This study provides a comprehensive review of current progress and challenges in recycling crumb rubber-modified asphalt (CRMA) pavements. It examines key aspects, including mechanical performance, rejuvenation methods, chemical characterization, practical case studies, and environmental implications. Particular emphasis is given to the technical barriers that influence recyclability, such as the mix design for recycled mix, accounting for the combined aging of both the asphalt binder and the crumb rubber particles, and optimizing the rubber content alongside chemical interaction of rejuvenating agents. Existing research indicates that several traditional recycling practices, especially full-depth reclamation and hot central plant recycling, are generally suitable for …

Integrating Sustainability Into Engineering Education, Riley R. Moller

Master's Theses

Engineering decisions shape lasting technology that affects environmental integrity, public safety, economic stability, and social equity. As global challenges such as climate change, infrastructure vulnerability, and rapid technological advancement intensify, the responsibilities placed on engineers continue to expand. Sustainability provides a framework for addressing these interconnected pressures through systems-based design and long-term thinking. Yet, sustainability education within engineering programs remains unevenly integrated, often positioned as elective or peripheral rather than as a foundational component of professional preparation.

Prior research shows that sustainability is most frequently addressed through stand-alone courses rather than embedded across required curricula, reflecting disciplinary structures that prioritize …

Research And Assessment Of Needs For Sign And Signal Maintenance, Megan White, Eric Green

Kentucky Transportation Center Research Report

Kentucky Transportation Cabinet (KYTC) sign and signal crews have expressed multiple concerns related to compensation, expertise, and having the financial and personnel resources needed to help the agency comply with Manual on Uniform Traffic Control Devices (MUTCD) guidelines while continuing to perform routine job duties. Internal reorganizations and personnel changes have reduced staffing and budgets available to underwrite the activities of sign and signal crews even as workloads have remained steady or increased. To document the challenges facing sign and signal crews and associated engineering staff, Kentucky Transportation Center (KTC) researchers administered a statewide survey. Respondents gave their perspectives on …

Building And Facility Asset Inventory Assessment And Maintenance, Catherine Keathley, Bethany Paris, Jon Wilcoxson

Kentucky Transportation Center Research Report

The Kentucky Transportation Cabinet (KYTC) manages approximately 1,500 buildings statewide, including facilities such as office buildings, maintenance and equipment garages, and storage sheds. Because managing buildings and properties requires considerable effort, agency decision makers need reliable monitoring and management tools that generate and organize data which can be used to determine the best course of action for facility maintenance and replacement. In addition to assessing the Cabinet’s building inventory, this report advances recommendations to improve the collection, management, and reporting of facility-related data. Assessment of the inventory managed by KYTC included geolocation of all properties and the buildings therein. Once …

Strategies For Extending The Service Life Of Prestressed Concrete I-Shaped Beams, Sanjoy Kumar Bhowmik

Dissertations

Prestressed concrete (PSC) I-shaped beams are widely used in bridge construction because of their structural efficiency and durability. The service life of these beams is reduced and the maintenance frequency is increased due to the distress during fabrication and subsequent deterioration. Although several mitigation strategies have been proposed and implemented, beam end cracking during fabrication remains a major concern. The causes and mitigation strategies for beam end cracking have been studied for decades, but there have been no comprehensive studies utilizing beam end strains during fabrication and lifting at prefabrication plants under normal operational conditions. Moreover, existing maintenance and repair …

Kytc Crash Modification Factor Recommendation List Online Tool, William Staats, Reginald Souleyrette, Teng Alex Wang, Mohammad Zana Majidi

Kentucky Transportation Center Research Report

Transportation practitioners use crash modification factors/functions (CMFs) to calculate the number of crashes expected once a countermeasure has been implemented. When evaluating design alternatives, CMFs can be used in conjunction with safety performance functions (SPFs) to derive crash predictions. The Federal Highway Administration (FHWA) maintains the CMF Clearinghouse as a repository for CMFs. Contributions are submitted by researchers across the U.S., Canada, and throughout the world. Typically, individual countermeasures are associated with multiple CMFs. Some CMFs only apply to a specific facility or crash types. CMF quality varies, and some only apply to a specific facility and/or crash types, regions, …

Matlab Shake Table Control And Data Acquisition System, Abigail Austin

Architectural Engineering

The College of Architecture and Environmental Design’s (CAED) seismic laboratory shake table is used for earthquake engineering education and experimental testing. However, the existing control system is outdated and difficult for students unfamiliar with the system to operate. The objective of this project was to develop a MATLAB-based control and data acquisition application to simplify shake table operation and improve accessibility, of both operation and output, for student users.

The developed application imports earthquake acceleration records, scales the input motions to the operational limits of the shake table, and executes the desires motion through the existing hardware system. Experimental data …

Development Of Kytc’S Context Classification Network, Jill Asher, Megan White, Eric Green, Christopher Van Dyke

Kentucky Transportation Center Research Report

Transportation agencies have adopted context-based classification systems that classify roadways based on the surrounding environment and user types. This offers a more comprehensive and multimodal perspective than traditional functional classification. While the Kentucky Transportation Cabinet (KYTC) has begun using project-level context classification, the agency will benefit from introducing network-level context classification. This will improve guidance, enhance project prioritization, and support the development of projects that better address the needs of all users. Responding to this need, Kentucky Transportation Center (KTC) researchers, in conjunction with KYTC staff, created a GIS-based model to build a context classification network that covers all state-maintained …

Boundary Influence In Truncated Groundwater Models: Reconstructing A Local-Scale Modflow Model From A Consultant-Developed Regional Model In The Monterey Subbasin, Bruce K. Liscomb

Master's Theses

Regional groundwater models built by consultants contain valuable calibrated frameworks but are often too large and complex for repeated local-scale analysis. Rather than rebuilding an entirely new smaller model, this study truncates the existing consultant-built regional model of the Monterey Subbasin, preserving the original grid structure and parameter framework while reducing the active domain to a manageable size for planning-level use. A key finding is that boundary-condition representation exerted a dominant influence on simulated groundwater behavior within the truncated domain, highlighting that truncation is a structural decision that meaningfully affects how the model responds. Model performance was evaluated two ways. …

A Performance-Weighted Environmental Assessment Of Ultra-High-Volume Fly Ash Substitution In Portland Cement Concrete, Youngguk Seo, M.A. Karim, Teddy Tzvetkov, Joshua Hardy

Faculty Articles

Fly ash substitution for cement in Portland cement concrete (PCC) has been regarded as a sustainable solution, but its widespread application remains constrained by concerns over mechanical performance and durability of PCC, especially at higher replacement rates. This study evaluates PCC mixes incorporating fly ash Type C (FA-C) or Type F (FA-F) across cement replacement rates from 10% to 90%, tracking fresh-state workability, compressive strength, and surface electrical resistivity at 7, 14, and 28 curing days. A process-based life cycle assessment (LCA) with the TRACI 2.1 method quantified global warming potential (GWP, kg CO₂/m³) under a …

From Ports To Projects: Estimating The Impact Of Supply Chain Volatility And Trade Policy Changes On Construction Material Prices, Ahmed Shiha, Islam H. El-Adaway

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Construction material markets are often reliant on imported commodities. Import tariffs and temporary trade barriers disrupt supply chains, presenting stakeholders with uncertainties regarding how such disruption impacts construction material prices. Despite the plethora of research efforts that examine the effects of economic conditions on construction material prices, the impacts of the import quantities remain understudied. This paper fills this knowledge gap using a multistep methodology. First, the prices of major construction materials and the quantities of the relevant imported commodities are retrieved. Second, the stability of their historical trends was assessed using econometrics-based tests. Third, a nonlinear autoregressive distributed lag …

Reinforced Concrete Design Fundamentals, Belen Stephanie Martinez Espinoza, Estevan Jacob Perez

Architectural Engineering

Hispanic workers make up a large and growing portion of the construction workforce in the United States; particularly in California, the percentage of construction workers who are Hispanic is estimated to be about 55% as of 2021 (Elkins). Many of these workers are Spanish-speaking, yet there is still a gap between technical engineering design and what is understood and applied in the field. One major reason for this gap is the lack of clear bilingual resources. To bridge the gap, a 48-page bilingual booklet titled Reinforced Concrete Design Fundamentals (Fundamentos del Diseño de Concreto Reforzado in Spanish) was created. This …

Design And Construction Of Caed Support Shop Steel Fence On Existing Cmu Wall, Jared Gustavo Martinez, Agustin Dominguez Jimenez

Architectural Engineering

This project involved the design, testing, fabrication, and construction of a new steel fence system for the CAED support shop at California Polytechnic State University, San Luis Obispo. The fence was designed to attach to an existing CMU wall and serve as a future attachment point for a removable shade canopy system. Experimental testing was performed on multiple turnbuckles to establish a conservative design load for the structural design of the fence posts, baseplates, welds, and anchorage connections. In addition to meeting structural requirements, the project incorporated architectural elements inspired by the original fence and surrounding CAED shop environment. The …

Tanzania Mbesese Initiative 2026, June Ezzell, Sam Liebman, Noah Beyer, Kate Hamilton, Luke Vollert, Kylee Borgen, Cody Balazs, Meg Mclaughlin

Architectural Engineering

The Tanzania Mbesese Initiative 2026 Senior Project supports a multi-year design-build effort to establish the Same Polytechnic College in Same, Tanzania. This community faces high poverty levels and limited access to higher education, necessitating sustainable infrastructure to support tertiary education. To prepare for the upcoming July phase of construction, an eight-student Architectural Engineering team designed three practical and resilient structures: a Shade Structure, a Water Collection Structure, and a Reusable Scaffolding system. The final design applied structural analysis, modeling, and hand-tool fabrication practice to balance material efficiency with long-term structural durability. The deliverables provide comprehensive construction documentation, complete material takeoffs, …

Design And Implementation Of A Honeycomb Damping System For The 2026 Eeri Seismic Design Competition, Vera Nguyen, Lauryn Wojcik

Architectural Engineering

The authors of this report were a part of the 2026 Earthquake Engineering Research Institute (EERI) chapter at California Polytechnic State University, San Luis Obispo. In July 2026, they will travel to Portland, Oregon with 12 students to compete in the Undergraduate Seismic Design Competition hosted by EERI. The competition required teams to develop a comprehensive structural design proposal that included computer-based modeling and analysis, construction of three physical models, and the preparation of both a technical poster and oral presentation for a proposed high-rise building located in Portland, Oregon. Cal Poly’s “Illahee Tower” was designed with an emphasis on …

Skip The Grid: Bringing Photovoltaic Energy To The Navajo And Hopi Nations, Emily Edmondson

Construction Management

Skip the Grid is an interdisciplinary service-learning initiative that provides off-grid solar energy systems to households within the Navajo and Hopi Nations that lack access to electricity. In March 2026, students from five academic disciplines at California Polytechnic State University partnered with industry professionals and community organizations to complete the fifth annual installation trip. The project's purpose was to improve quality of life by providing reliable access to lighting, refrigeration, and small-scale electrical power in underserved communities where traditional grid expansion is extremely costly. Preparation for the project included fundraising, procurement, technical training, and coordination among multiple stakeholders. Participants were …

2026 Annual V.E.S.T Hackathon: Improving Gender Inclusivity Of Glove Fitting, Makena E. Fix

Construction Management

Safety gloves are an essential part of field personnel's personal protective equipment (PPE). Gloves protect against cuts, burns, chemicals, and other hazards. Properly fitting gloves reduce the risk of injury by enabling the suitable use of task-specific protection. The 2026 Verifying Everyone’s Safety Together (V.E.S.T) Hackathon was hosted to identify ways in which gloves fit workers differently, and evaluated six different glove types, ranging from woven cut rated to firefighting gloves. To understand experiences faced by workers with their PPE, firefighters were interviewed and discussions were held at the Hackathon. The collaborative event brought industry members and students together to …