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Full-Text Articles in Engineering

Effect Of Ordinary Portland Cement On Some Properties Of Pervious Geopolymer Concrete, Wasan I. Khalil, Qais J. Frayyeh, Haider T. Abed Jul 2026

Effect Of Ordinary Portland Cement On Some Properties Of Pervious Geopolymer Concrete, Wasan I. Khalil, Qais J. Frayyeh, Haider T. Abed

Engineering and Technology Journal

In this research, a study is made on the Pervious Geopolymer Concrete (PGC), which is based on local material (Metakaolin). The inclusion of Ordinary Portland Cement (OPC) as a partial substitute for Metakaolin (MK) for the production of (PGCs) has also been investigated. Pervious Geopolymer concrete was outputted from the local Metakaolin (MK), and ordinary Portland cement (OPC) as a partial substitute by weight of MK and silicate of sodium (Na2SiO3) and hydroxide of sodium (NaOH) solution. All PGC samples were cured after 24 hours from casting for five hours at a temperature degree of 50 ° C, then they …


Utilizing Waste Paper Ash As Partial Cement Replacement In Concrete, Karim Hassan Jun 2026

Utilizing Waste Paper Ash As Partial Cement Replacement In Concrete, Karim Hassan

Thesis/ Dissertation Defenses

The concrete industry has a considerable environmental impact. The manufacture of ordinary Portland cement (OPC) emits a large amount of carbon dioxide, while the extensive extraction of virgin natural aggregates further burdens the environment during concrete production. This thesis is concerned with the development of low-carbon concrete through the combined utilization of waste paper ash (WPA), recycled aggregates, and accelerated carbonation curing. The main objective is to reduce the environmental footprint of concrete products, including masonry units, by enhancing their carbon sequestration potential, decreasing the use of cement, and alleviating reliance on virgin aggregates, while also maintaining adequate mechanical and …


Characterization Of The Thermally Driven Red Hue Effect In Coated And Uncoated Concrete Systems: Implications For Post-Fire Assessment In Wildland Urban Interface Communities, Juan C. Palominos Jr Jun 2026

Characterization Of The Thermally Driven Red Hue Effect In Coated And Uncoated Concrete Systems: Implications For Post-Fire Assessment In Wildland Urban Interface Communities, Juan C. Palominos Jr

Master's Theses

The increasing frequency and intensity of Wildland-Urban Interface (WUI) wildfires, such as the destructive 2025 Pacific Palisades Fire that destroyed over 6,000 structures, have underscored the urgent need for rapid post-fire safety assessment methodologies. This study sought to quantitatively characterize the Thermally Driven Red Hue Effect (TRHE), a unique, irreversible color shift observed in architectural coatings and concrete substrates, to determine its reliability as a permanent visual record of thermal exposure. Concrete substrates were formulated with three distinct coarse aggregates: gold granite (14.7% Fe), red cinder (22.4% Fe), and green rock (33.6% Fe) and coated with a 20 PVC waterborne …


Concrete And Masonry Code (Beams), Michael Alexander Simas Rocha Jun 2026

Concrete And Masonry Code (Beams), Michael Alexander Simas Rocha

Architectural Engineering

This report only covers the beam design of the code that was written. The end goal of this project is to write code for concrete and masonry following what was taught in the lecture classes. This project is acting as a foundation for the end goal of a program that can compete with SAP2000, ETABS, RISA, and others. One final goal is to have the print out have the look and feel of having been done by hand. While coding; several factors were recorded including time spent coding, debugging, and then to do three problems by hand vs how long …


Ada Concrete Walkway Improvements At The Gala Pride And Diversity Center, Jonathan A. Mintz, Manuel Gonzalez Jun 2026

Ada Concrete Walkway Improvements At The Gala Pride And Diversity Center, Jonathan A. Mintz, Manuel Gonzalez

Construction Management

This paper presents the planning, design, and construction of an accessible concrete walkway completed for the GALA Pride and Diversity Center in San Luis Obispo, California. The project addressed an accessibility gap between the center's front entrance and rear parking lot through a combination of site preparation, concrete work, retaining wall construction, and supporting improvements. Construction was managed around the active events schedule while staying within the constraints of a nonprofit budget. Challenges encountered during the project included scope changes, material selection decisions, and client coordination. The completed walkway provides a safe and stable path for all visitors and directly …


International Construction In El Salvador, Daniel Roberts Jun 2026

International Construction In El Salvador, Daniel Roberts

Construction Management

My senior project focused on participating in international construction operations in El Salvador through hands-on involvement in the construction of a steel warehouse facility and a small residential home. The project emphasized structural concrete placement, field coordination, construction sequencing, and adaptation to regional construction practices. Work included assisting with concrete foundations, slab preparation, reinforcing steel placement, masonry work, and general site coordination activities. The experience provided practical exposure to labor productivity, material availability, scheduling challenges, and construction methods commonly used in developing regions. The project also highlighted the importance of communication, problem-solving, and flexibility when working in an international construction …


Sorption And Thermal Conductivity Of Concrete Containing Aggregates Of E-Waste, Rakesh Kumar Saini, Praveen Kumar May 2026

Sorption And Thermal Conductivity Of Concrete Containing Aggregates Of E-Waste, Rakesh Kumar Saini, Praveen Kumar

Journal of Sustainable Construction Materials and Technologies

In many parts of the world, substantial energy is used to maintain comfortable temperatures in inner parts of the buildings for living and working. Construction materials with low thermal conductivity, if used in the exterior walls and façade etc. in such structures can be useful in lowering the energy demand. On the other hand, moisture ingress through sorption is a common factor contributing in degradation of concrete structures with time. Constituents of concrete may be engineered to some extent to get both the desired attributes, lower thermal conductivity and sorption than normal concrete. The rapid increase in electronic waste, or …


Exploring The Stress-Strain Relationship Of Lightweight Concrete To Enhance The Lifecycle Performance Of Transportation Highways And Bridges, Fariborz M. Tehrani Apr 2026

Exploring The Stress-Strain Relationship Of Lightweight Concrete To Enhance The Lifecycle Performance Of Transportation Highways And Bridges, Fariborz M. Tehrani

Mineta Transportation Institute

Concrete is the primary construction material of bridges, roads, and other transportation infrastructure across the United States, but conventional normal-weight concrete (NWC) is heavy, prone to cracking, and expensive to maintain over time. This study examines the mechanical properties, durability, and lifecycle performance of lightweight aggregate concrete (LWC) and internally cured concrete (ICC) as alternatives in transportation infrastructure applications. Through laboratory testing, computer modeling, and lifecycle analysis, the research evaluates how these materials perform in terms of strength, flexibility, durability, cost, and environmental impact. The results show that LWC and ICC can meet required strength levels while being lighter and …


Sustainability In Concrete: Decision-Makers, Dismissal Points, And A Framework For Implementation, Max Dennison Apr 2026

Sustainability In Concrete: Decision-Makers, Dismissal Points, And A Framework For Implementation, Max Dennison

Construction Management

Concrete is essential to modern infrastructure, but is also one of the largest sources of embodied carbon, with cement production alone responsible for a significant share of global CO₂ emissions. Although low-carbon and otherwise “sustainable” concrete technologies are growing, their use in everyday projects remains limited. This research investigates why sustainable concrete options are most often dismissed during the project lifecycle, who drives these decisions, and what conditions are needed to enable broader adoption. Using a combination of literature review and semi-structured interviews with professionals in contracting, life-cycle assessment, sustainability consulting, and materials production, the study maps decision points from …


Feasibility Of Using Recycled Waste Plastic In Concrete Pavements In Nebraska, Amasi Hajahja, Jamilla Teixeira, George Morcous Mar 2026

Feasibility Of Using Recycled Waste Plastic In Concrete Pavements In Nebraska, Amasi Hajahja, Jamilla Teixeira, George Morcous

Nebraska Department of Transportation: Research Reports

Waste plastic (WP) is a growing environmental concern due to its non-biodegradable nature, large-scale production, and harmful impact on natural resources. With nearly 75% of WP in the U.S. ending up in landfills, effective recycling strategies are urgently needed. In parallel, the limited availability of natural aggregates highlights the need for alternative materials in concrete construction. This study investigates the feasibility of using recycled waste plastic (RWP) in concrete mixtures, both as aggregates and fibers for rigid pavement applications in Nebraska. Concrete mixtures were prepared by partially replacing natural fine aggregates with recycled plastic aggregates (RPA) at replacement levels of …


Evaluating The Impact Of Aggregate Size And Reinforcement On Alkali-Silica Reaction In Concrete Through Nondestructive Testing Techniques, Li Ai, David Bianco, Vafa Soltangharaei, Rafal Anay, Mahmoud Bayat, Paul Ziehl Mar 2026

Evaluating The Impact Of Aggregate Size And Reinforcement On Alkali-Silica Reaction In Concrete Through Nondestructive Testing Techniques, Li Ai, David Bianco, Vafa Soltangharaei, Rafal Anay, Mahmoud Bayat, Paul Ziehl

Civil Engineering Faculty Publications

This research investigates different nondestructive evaluation (NDE) methods to assess concrete under alkali-silica reaction (ASR) development. Four methods including acoustic emission (AE), ultrasonic pulse velocity (UPV), crack width measurement, and strain measurement were applied to reactive and control specimens under accelerated ASR conditioning. The innovation lies in using NDE methods to monitor concrete with varying aggregate sizes, quantifying method sensitivity through measured indices, and highlighting the effectiveness of each method to capture ASR development. The results indicate that the unconfined reactive fine-aggregate sample exhibited isotropic expansion, while coarse-aggregate specimens showed around 50 % greater longitudinal expansion and AE cumulative signal …


Utah’S Waste Glass Makes Concrete Stronger And Improves Durability, Rosemary Yahne Feb 2026

Utah’S Waste Glass Makes Concrete Stronger And Improves Durability, Rosemary Yahne

Research on Capitol Hill

Utah landfills receive thousands of tons of waste glass annually while our concrete industry relies on cement, one of the world's largest sources of CO₂ emissions.

We discovered that finely ground recycled glass can replace up to 30% of cement in concrete and improve performance.

This research tests whether Utah's waste-recycled glass can create stronger, more durable concrete for our roads, bridges, and buildings.


Towards Decarbonizing Concrete Industry In Egypt: Material Alternatives, And Economic Viability, Reem Gamal Jan 2026

Towards Decarbonizing Concrete Industry In Egypt: Material Alternatives, And Economic Viability, Reem Gamal

Theses and Dissertations

The construction industry remains one of the largest contributors to global greenhouse gas emissions, with cement and steel production accounting for approximately 15% of total emissions. As global infrastructure demands continue to rise, there is an increasing need for practical tools that support low-carbon construction practices in line with international climate commitments. This research presents the development and testing of a mathematical, adaptable decision support system designed to assess both the environmental and financial impacts of material selection in concrete production. Focusing on life cycle stages A1 to A3, raw material extraction, transportation, and manufacturing, the decision support system enables …


Improving Ground Penetrating Radar Calibration For Chloride Assessment In Reinforced Concrete Bridge Decks, Camila Silva Wendland Jan 2026

Improving Ground Penetrating Radar Calibration For Chloride Assessment In Reinforced Concrete Bridge Decks, Camila Silva Wendland

Engineering Theses

This study investigates how ground penetrating radar (GPR) can be used to estimate chloride content in reinforced concrete bridge decks. Chloride buildup at the rebar level can lead to corrosion and structural damage, but current testing methods are destructive and limited to small sample areas. GPR offers a non-destructive alternative, but interpreting reflection amplitudes is challenging because they are affected by multiple factors, including moisture content and rebar depth. To address this, a simulation-based calibration method was developed. Finite-difference time-domain simulations were used to study how chloride, moisture, and rebar depth influence GPR reflection amplitudes. A depth correction method was …


Innovative Smart Sensing System For Accurate Monitoring Of Uhpc Setting Time, Ted Atera, Khalilullah Taj, Masoud Pasbani, Yen-Fang Su Jan 2026

Innovative Smart Sensing System For Accurate Monitoring Of Uhpc Setting Time, Ted Atera, Khalilullah Taj, Masoud Pasbani, Yen-Fang Su

Distinguished Undergraduate Researcher Program

Ultra-High-Performance Concrete (UHPC) is an advanced concrete material known for its strength and durability. Its superior mechanical properties make it an ideal material for demanding structural applications such as bridges. Accurate setting time measurements are crucial in helping to optimise the performance of UHPC. All conventional methods and standards for measuring the setting time of concrete rely on using expensive specialised equipment, such as the Vicat apparatus, which assesses penetration depth or resistance. However, these methods may not be well-suited for UHPC due to its rapid surface drying while the interior remains fresh. This prevents free needle penetration and leads …


Structural Behavior Of Reinforced Concrete Columns Under Eccentric Loads Strengthened By Steel Jackets Filled With Normal And High-Strength Concrete, Mahmoud Ahmed M. Amin, Mahmoud Mostafa El Hawary, Ahmed Shaheen, Ibrahim M. Mashhour Dec 2025

Structural Behavior Of Reinforced Concrete Columns Under Eccentric Loads Strengthened By Steel Jackets Filled With Normal And High-Strength Concrete, Mahmoud Ahmed M. Amin, Mahmoud Mostafa El Hawary, Ahmed Shaheen, Ibrahim M. Mashhour

HBRC Journal

Reinforced concrete (RC) columns are essential structural components in buildings and infrastructure, providing vertical load support and stability. However, these columns can be degraded over time due to various factors, such as environmental exposure, seismic events, and increased loading demands. As a result, the need for effective and reliable column-strengthening techniques arises to ensure the safety, durability, and longevity of structures. The main objective of this study is to investigate how fully strengthening damaged columns affects load-bearing capacity and overall structural performance. Moreover, this study tested thirteen reinforced concrete columns during the experimental program. The original dimensions of these columns …


Durability Of Basalt Fiber-Reinforced Polymer Bars In Moist Concrete Under Sustained Load, Osama Ahmed Nov 2025

Durability Of Basalt Fiber-Reinforced Polymer Bars In Moist Concrete Under Sustained Load, Osama Ahmed

Thesis/ Dissertation Defenses

This thesis is concerned with the long-term durability of basalt fiber-reinforced polymer (BFRP) bars embedded in moist concrete. The study focuses on the combined effects of exposure duration, elevated temperature, and sustained tensile stress, which together influence the mechanical and chemical stability of BFRP reinforcement in aggressive environments. The main objective is to evaluate the degradation mechanisms of BFRP bars subjected to coupled hygrothermal and mechanical conditions and to develop a predictive durability model capable of estimating service life under realistic climate scenarios. Concrete-encased BFRP bars were conditioned at three temperatures (20, 40, and 60°C), three durations (3, 6, and …


The Impact Of Water On Concrete Quality, Ibush Luzha, Bujar Aliu, Teodor Zguro Oct 2025

The Impact Of Water On Concrete Quality, Ibush Luzha, Bujar Aliu, Teodor Zguro

UBT International Conference

Water is vital to concrete, and it has a dual role. This paper will examine the impact of the quantity (water/cement ratio - W/C) and water quality on concrete. W/C directly affects workability, mechanical strength, porosity, and durability. A low W/C gives stronger concrete but with difficult workability; a high W/C improves workability but weakens mechanical properties and durability. Water quality is also critical; impurities such as chlorides, sulfates, and organic substances can negatively affect cement bonding and strength, cause corrosion of reinforcement, and degradation. Water is also essential for curing, which maximizes strength and durability. Therefore, strict control of …


Effect Of Granite Machine-Made Sand Properties On Concrete Performance, Wang Jiliang, Wei Xinyuan, Yu Bo Aug 2025

Effect Of Granite Machine-Made Sand Properties On Concrete Performance, Wang Jiliang, Wei Xinyuan, Yu Bo

Journal of China & Foreign Highway

As an important stone resource in China,granite is widely used in the preparation of machine-made sand and other building materials due to its stable physical properties and favorable mechanical performance.In order to promote the better application of granite in machine-made sand for cement concrete,this paper analyzed the mineral composition,particle grading,and mica content of granite machine-made sand.It systematically summarized the influence of these characteristics on the mechanical properties,durability,and volumetric stability of concrete.The results show that the concrete performance declines with increasing mica and stone powder content in granite machine-made sand.Properly limiting their content can improve the mechanical properties and durability of …


A Review On The Use Of Salt And Sugar As Natural Admixtures In Concrete, Noura A. Yassine, Lelian W. Elkhatib, Adel Elkordi, Mohammed Sonebi, Jamal Khatib Jun 2025

A Review On The Use Of Salt And Sugar As Natural Admixtures In Concrete, Noura A. Yassine, Lelian W. Elkhatib, Adel Elkordi, Mohammed Sonebi, Jamal Khatib

BAU Journal - Science and Technology

Due to the large increase in construction nowadays, the focus on the reduction of waste in the environment and saving cost becomes crucial. This issue, if solved, will conserve natural materials and make an eco-friendly environment. According to this, the use of natural materials, specifically in concrete/mortar, will shape a green and sustainable environment. One of the most used materials in construction is concrete where some additives like accelerators and retarders are added in order to enhance and modify some properties of concrete. These additives are beneficial and important to be used specifically in case of different weather conditions. Weather …


Optimizing The Use Of Sustainable Additives In Subgrade Soil Stabilization, Orchi Mallick Jun 2025

Optimizing The Use Of Sustainable Additives In Subgrade Soil Stabilization, Orchi Mallick

Student Theses and Dissertations

Subgrade soil critically impacts pavement lifespan, where poor conditions lead to premature failure. This study evaluates soil stabilization of AASTHO classified, A-4 and A-6 soil, using sustainable additives: Rice Husk Ash (RHA), Reclaimed Fly Ash (RFA), and a traditional stabilizer Hydrated Lime (HL). Laboratory tests (Atterberg Limits, Modified Proctor, California Bearing Ratio (CBR), and Free Swell) were conducted on untreated and treated soils with RHA (3%, 6%, and 9% by weight), HL (1%, 3%, and 5% by weight), RFA (4%, 6%, and 8% by weight), and combinations of HL + RHA. Results showed all stabilizers improved strength and reduced swell. …


Concrete Patio Demolition And Construction, Tyler Nielsen Jun 2025

Concrete Patio Demolition And Construction, Tyler Nielsen

Construction Management

A 6.25 cubic yard unreinforced concrete patio was constructed for the non-profit organization. This project included three phases: concrete slab demolition, grading and formwork, and concrete pouring. Each phase was estimated and then received owner approval prior to execution. The demolition phase involved obtaining city permits for a roll-off container for debris removal. This phase also included two days of work with over 10 demolition crew members, who were given the required training and equipment to ensure safety and productivity. The following weeks included grading and setting up formwork. Once the grade was complete, the formwork was laid out and …


Son Care Foundation – Pergola Structure Construction, Jackson Landless Jun 2025

Son Care Foundation – Pergola Structure Construction, Jackson Landless

Construction Management

This paper covers the construction process of a pergola structure for the Son Care Foundation in San Luis Obispo, California. The project’s goal in this study is to create a welcoming outdoor space for clients their dogs. Excavating four footings, fabricating custom rebar cages, and pouring concrete using fast-setting mix were all part of the construction efforts. Framing the structure required precise calculations to accommodate for the slope and corner braces. The matching white paint and corrugated PVC roof further achieved the desired aesthetic the client requested. Trial and error, practical experience, and cooperation with local material suppliers and maintenance …


Optimizing Concrete Strength: How Nanomaterials And Ai Redefine Mix Design, Dan Huang, Guangshuai Han, Ziyang Tang May 2025

Optimizing Concrete Strength: How Nanomaterials And Ai Redefine Mix Design, Dan Huang, Guangshuai Han, Ziyang Tang

Physics and Engineering Science

Nanomaterials and supplementary cementitious materials (SCMs) are typically used together in efforts to enhance the performance of concrete and mitigate the environmental impact of concrete construction. However, the complex interactions between nanomaterials, SCMs, and cement make concrete mix design a challenging, iterative, and labor-intensive process, often relying on trial-and-error experimentation. Machine learning (ML) offers an opportunity to better understand the influence of input parameters and to accelerate the optimization of mix designs through data-driven insights. This study proposes an open-source and easy-to-access framework, Canopy, to support the concrete research community in optimizing mix design. Using a dataset collected from the …


Evaluation Of Novel Jointless Engineered Cementitious Composite Ultrathin Whitetopping (Ecc-Utw) Overlay, Hassan Noorvand, Marwa Hassan, Tyson Rupnow, Ricardo Hungria May 2025

Evaluation Of Novel Jointless Engineered Cementitious Composite Ultrathin Whitetopping (Ecc-Utw) Overlay, Hassan Noorvand, Marwa Hassan, Tyson Rupnow, Ricardo Hungria

Publications

The present work corresponds to the development and the application of a cost-effective Engineered Cementitious Composites (ECC) mix design with the name M3-1.5%. Once the material was developed it was applied in the construction of a novel engineered cementitious composites ultrathin whitetopping (ECC-UTW) overlay. The overlay was constructed in May 2019 at the Pavement Research Facility (PRF) in Port Allen, Louisiana. The project was built on top of a distressed asphalt pavement corresponding to a previous project. During the construction, samples were gathered and subjected to testing after 28 days through means of compressive, uniaxial tension and flexural strength tests. …


Development Of Low-Carbon Cementitious Composites With Volcanic Ash And Calcium Carbide Residue Using Carbonation Curing, Jad Samir Bawab Apr 2025

Development Of Low-Carbon Cementitious Composites With Volcanic Ash And Calcium Carbide Residue Using Carbonation Curing, Jad Samir Bawab

Thesis/ Dissertation Defenses

The production and use of cement and concrete is a major contributor to numerous environmental problems, primarily centered around high carbon emissions, extensive resource depletion, and vast waste generation. This thesis aims to develop and characterize low-carbon concrete by using volcanic ash (VA) and calcium carbide residue (CCR) as partial cement substitutes while exposing the cementitious composite to accelerated carbonation curing. The study is a multi-level assessment of the incorporated materials and curing method divided into four phases. The first stage studied and optimized the CCR content and carbonation curing parameters of carbonation-cured concrete. It was revealed that using 5% …


Use Of Wastewater Grit And Milorganite Chaff In Concrete, Carter Deinhammer Apr 2025

Use Of Wastewater Grit And Milorganite Chaff In Concrete, Carter Deinhammer

Master's Theses (2009 -)

Wastewater grit is a major byproduct from preliminary municipal wastewater treatment. Chaff is a collection of dried biosolids generated as a waste product from Milorganite® fertilizer production. Because landfilling is a costly and unsustainable method, the development of technologies for diverting grit from landfills to a useful product by tapping grit’s inherent values (e.g., sand and gravel) are of great interest. Chaff, consisting of fibers, provides a potential source for bolstering concrete tensile strength through internal means. This research has proposed a concept of grit and chaff additive-based concrete, an expansion of the grit-assisted patch material developed (GAP) in previous …


The Influence Of Dispersed Fillers On The Mechanical Properties Of Sulfur Polymer Heterocomposites, Erkin Abdukhafizovich Rakhmatov, Durdiymurad Gurbanovich Gadamov, Umida Alijonovna Ziyamukhamedova, Jasurbek Himmat Ugli Nafasov, Elbek Tukhtanazar Ugli Turgunaliev, Shokhjakhon Uktam Ugli Abdurakhimov Mar 2025

The Influence Of Dispersed Fillers On The Mechanical Properties Of Sulfur Polymer Heterocomposites, Erkin Abdukhafizovich Rakhmatov, Durdiymurad Gurbanovich Gadamov, Umida Alijonovna Ziyamukhamedova, Jasurbek Himmat Ugli Nafasov, Elbek Tukhtanazar Ugli Turgunaliev, Shokhjakhon Uktam Ugli Abdurakhimov

Technical science and innovation

This article discusses improving the physical, mechanical, and operational properties of composite materials modified with sulfur-containing plasticizers used in the modern construction industry. Furthermore, based on an in-depth analysis of the literature, the types and sizes of fillers and the significance of their mixing technology in the formation of a structure with low porosity of a composite material with a sulfur binder have been studied. The article thoroughly describes a method for obtaining a composite material with a stable sulfur-containing binder, the processes of preparing a solid filler, impregnating the filler with an organic modifier, humidifying and heating the filler …


Dynamic Tensile Properties Of Thermally Treated Concrete Specimens Subjected To Varied Heating Rates: An Investigation Using The Digital Image Correlation Method, Ronghua Shu, Jiabao Cheng, Guang Xu, Yuzhang Lai, Lijinhong Huang Mar 2025

Dynamic Tensile Properties Of Thermally Treated Concrete Specimens Subjected To Varied Heating Rates: An Investigation Using The Digital Image Correlation Method, Ronghua Shu, Jiabao Cheng, Guang Xu, Yuzhang Lai, Lijinhong Huang

Mining Engineering Faculty Research & Creative Works

In concrete engineering, high temperatures at varying heating rates significantly affect the stability of concrete structures. In this paper, the dynamic tensile characteristics were investigated on concrete specimens subjected to heating rates ranging from 2 to 40 °C/min, using the digital image correlation (DIC) method. The results reveal a critical heating rate threshold, between 5 and 10 °C/min, which marks a shift in the influence of heating rates on both physical and dynamic tensile properties. Below this threshold, changes are minimal, but beyond it, significant effects are observed. As the heating rate increases, longitudinal wave velocity, density, and mass decrease, …


Molecular Scale Investigations Of Interactions Between Pfas And Concrete, Eric E. Keeler Mar 2025

Molecular Scale Investigations Of Interactions Between Pfas And Concrete, Eric E. Keeler

Theses and Dissertations

Per- and polyfluoroalkyl substances (PFAS), widely referred to as “forever chemicals,” exhibit high environmental persistence and potential health risks due to their robust carbon-fluorine bonds. These substances are prevalent in aqueous film-forming foams (AFFF), used in industrial and military applications, and are known to contaminate environmental surfaces, including concrete. This study aims to characterize the molecular-level interaction energies of six PFAS species—PFOA, PFOS, PFHxS, PFHxA, 6:2 FTS, and PFBS—with calcium silicate, a key component of concrete, using density functional theory (DFT) calculations. Change in Gibbs free energy (ΔG) was determined for each of the interactions, revealing negative ΔG values for …