Engineering Commons^™

Co2-Induced Changes In Rheology, Structural Evolution, And Particle Characteristics Of Cement Paste, Seongho Han, Tae Yong Shin, Seung Mo Kim, Jae Hong Kim, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The injection of carbon dioxide (CO₂) into cementitious systems has emerged as a promising approach to enhancing sustainability in concrete production. This study explores the impact of CO₂ injection on the rheological behavior, structural build-up, and particle size evolution of cement paste by systematically varying the water-to-cement ratio (w/c) (0.35, 0.4, and 0.5) and CO₂ concentration (0.06, 0.28, and 0.84 mol). Rheological analysis revealed a significant increase in initial yield stress with CO₂ injection. Using the Modified Bingham model, yield stress increased by 72 % and 150 % for 0.28- and 0.84-mol CO₂, …

Influence Of Channel Geometry And Inflow Hydrograph On Hydraulics And Air Volume Around Shafts Of A Stormwater Main, Lylie Vindie Wilkie

Theses and Dissertations

Stormwater management in urban areas is complex, in part because of difficulties related to modeling water flowing in closed conduits, as well as to controlling odor, noise, and pipe corrosion. This thesis summarizes the main findings of a study on how changes in inflow discharge and the geometry of a stormwater main may affect water flow, and how changes in water depth impact air volume and pressure around an air shaft. The study is conducted using CHAN, a one-dimensional model that simulates both flow hydraulics in mains and associated changes in air volume and pressure around air shafts. Main difference …

Building Services Engineering September/October 2025

Building Services Engineering

No abstract provided.

Erosion Of Bermuda Grass Covered Soils, Oru-Ntui Johnwatters Nkiri

Theses and Dissertations

Earthen embankments are the most common type of embankment due to the relatively low cost, simplicity, and material availability. However, they are also the most prone to erosion related failure, typically due to overtopping and piping. Research has been conducted to identify ways to control soil erosion and protect earthen embankments with different approaches such as addition of chemicals and biopolymer to the soil, installation of protective layering (geotextiles, concrete), increased soil compaction, and use of vegetation. This thesis considers the use of Bermuda Grass to increase resistance to erosion and protect embankments from failure during overtopping. Grass coverage and …

Carbonated High-Al Steel Slag As Supplementary Cementitious Material: Synergy Of Carbonation At Elevated Temperature And Addition Of Gypsum, Nannan Zhang, Gao Deng, Wenyu Liao, Chuanlin Hu, Lingyu Chi, Hongyan Ma

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

High-Al steel slags, such as ladle metallurgy furnace (LMF) slag, substantially retard the early hydration of cement when incorporated into cement pastes, primarily due to the high mayenite content. In this study, carbonation of slag at elevated temperatures of 60°C and 80°C, combined with gypsum addition, was proposed to synergistically mitigate the retardation effect and enhance the early-age strength of cement pastes. The physical and chemical properties of slags carbonated at various temperatures were analyzed to elucidate their impact on cement performance as a supplementary cementitious material. The results indicate that higher temperatures enhance carbonation reactivity, accelerating the carbonation of …

Magnesium Sulfate Attack Of Alite Paste And Mitigation By Surface Carbonation: Monitoring And Comparison Using Novel Portable Fiber-Optic Raman Probe, Bohong Zhang, Gao Deng, Hongyan Ma, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

Sulfate attack on cement matrix is still a "confused world" especially when magnesium sulfate (MgSO₄) is the sulfate source. Accurate assessment of sulfate attack is essential for evaluating the structural integrity and durability of concrete in relevant environments. This study presents a portable fiber-optic Raman probe approach with 125 μm spatial resolution, designed for depth-resolved sulfate ingress monitoring in tricalcium silicate (C₃S, Alite) pastes. The probe is also used to evaluate the effectiveness of surface carbonation in mitigating sulfate attack. The results demonstrate a strong correlation between sulfate penetration depth and Raman spectral intensity ratios of sulfate-related vibrational …

Using Drone And Ai To Map Leaf Water Potential And Stem Water Potential For Water Stress Management In Commercial Vineyards, Alfonso F. Torres-Rua

Funded Research Records

No abstract provided.

Seismic Fragility Analysis Of Above-Ground Liquid Storage Tanks, Pooyan Khajeh Shahzanian

Dissertations and Theses

Liquid storage tanks are critical infrastructure, serving as key storage facilities for various products. As the contents in these tanks are usually highly toxic and flammable, damage to these structures under earthquakes can cause severe consequences, including energy shortage, fire and explosion, and spilling and long-term environmental damages.

Although new liquid storage tanks are designed according to the updated seismic design codes, large numbers of existing storage tanks were built before modern seismic design codes and did not undergo necessary seismic retrofitting. Observations and reports from past earthquakes demonstrate that these older tanks can be highly vulnerable to seismic excitation. …

Investigation Of Micronized Rubber Powder As An Alternative To Polymer Modifiers In Asphalt Pavement, Md Torikul Islam

Student Theses and Dissertations

Researchers have increasingly focused on polymer additives to enhance asphalt pavement performance. Crumb rubber (CR), derived from waste vehicle tires, has emerged as a potential modifier. This study investigates Micronized Rubber Powder (MRP), smaller than 75 μm, as an alternative to polymer modifiers. A PG 64-22 binder was modified with 5%, 10%, and 15% MRP (by weight), and the properties were compared with those of an SBS-modified PG 70-22 binder. Physical, mechanical, and chemical properties were assessed. The results indicated that MRP significantly increased viscosity and required higher processing temperatures. MRP-modified binders demonstrated improved rutting resistance, creep recovery, high-temperature performance, …

Experimental And Numerical Investigation On The Effect Of Projectile Mass And Apex Angle On Penetration Depth Into Sandy Soils, Abdul-Rahman K. Osman, Ahmed Elshesheny Dr, Mohamed S. Zahran Dr, Nabil M. Nagy Prof.

Journal of Engineering Research

Projectile penetration in granular soils remains a critical concern in defense engineering and ballistics research. This study presents an experimental and numerical investigation of rigid cone-tip projectile penetration into very dense sand, examining the influence of apex angle and projectile weight on penetration depth. Laboratory experiments were conducted using metallic projectiles with apex angles of 10°, 30°, 60°, and 90° and weights of 2.445, 3.87, 5.33, and 6.81 kg, dropped from a height of 4.295 m into a 500×500×500 mm wooden tank filled with sand to 400 mm height at 95% relative density. Through systematic testing, two empirical correlation …

Assessment Of Safety Monitoring Indexes Of High Rcc Gravity Dams Considering Hydraulic Fracture, Mohamed Ramdan, Jinsheng Jia Professor, Xu Li Professor

Journal of Engineering Research

High concrete gravity dams, particularly Roller-Compacted Concrete (RCC) types, face long-term safety challenges due to weak interlayer formation and crack propagation. This study presents a comprehensive evaluation of safety monitoring indexes for the Guxian high RCC dam (currently under construction in China) using both numerical and theoretical models. A Finite Element Method (FEM) was applied with two approaches: the strength reduction method, which considers weak layers, and the overloading method, which simulates extreme loading without accounting for material degradation. A comparative analysis between these two methods was conducted to determine which more effectively evaluates dam safety under varying conditions. Additionally, …

Flexural Behavior Of Sustainable Concrete Beams Containing Waste Tire Fibers And Recycled Aggregates, Wael M. Montaser Ass.Prof

Journal of Engineering Research

The increasing accumulation of diverse waste materials poses a significant societal challenge, highlighting the importance of developing methods to reuse such waste effectively. One promising solution involves incorporating recycled coarse aggregate (RCA) obtained from demolished concrete into new concrete mixtures. Additionally, tire-derived fibers (TDF), sourced from recycled tires, present an environmentally friendly substitute for conventional reinforcement materials. The integration of RCA with TDF in reinforced concrete beams offers a sustainable approach to enhancing structural performance. This experimental study investigates the flexural performance of reinforced concrete beams containing recycled coarse aggregate (RCA) and tire-derived fibers (TDF). Four mixes with varying RCA …

The Influence And Firing Of Zircon, Ilmenite, And Magnetite As Partial Sand Replacement On The Properties Of Concrete For Specialized Applications., Samy A. Fawzy

Journal of Engineering Research

This study investigates the impact of partially replacing sand with varying percentages (10%, 20%, 30%, and 50%) of zircon (ZrSiO4), ilmenite (FeTiO3), and magnetite (Fe3O4) on the physical and mechanical properties of concrete. The research focuses on evaluating the compressive strength, density and radiation shielding capabilities of the modified concrete mixtures. The effect of firing concrete cubes(600,900 and 1100 C) with various percentages of the three materials were studied also. The use of these heavy minerals aims to enhance concrete properties for specialized applications such as radiation shielding structures and high-density construction. Results indicate that increasing the replacement percentage of …

Performance Analysis Of Flapping-Foil Energy Harvesters Under Shear-Flow Conditions, Maqusud Alam, Bubryur Kim, Shehnaz Akhtar, Sujeen Song, Zengshun Chen, Jinwoo An

Civil Engineering Faculty Publications

Flapping-foil energy harvesters represent a promising technology for extracting energy from fluid flows, although their performance under shear-flow conditions is poorly understood. To address this research gap, we investigated the impact of power-law shear flow on the performance of flapping-foil energy harvesters. We conducted numerical simulations at different Reynolds numbers (Re = 1000, 50 000, and 500 000) under uniform-flow and shear-flow conditions. Based on the results, shear flow minimally affected the power outputs at Re = 1000 and 50 000, where viscous forces dominate the flow dynamics. However, at Re = 500 000, shear flow significantly reduced the …

Experimental And Theoretical Studies Of Novel Resilient Smart Shear Keys For Speedy Functional Recovery Of Highway Bridges After Extreme Events, Xinzhe Yuan, Jun Han, Jian Zhong, Haibin Zhang, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Sacrificial shear keys in small-to-medium-span highway bridges mainly provide lateral support to the bridge superstructure under extreme events such as earthquake and/or tsunami. However, such support could lead to irreparable harm to important bridge elements like abutments and bent caps (base), delaying the functional recovery of bridges in the aftermath. In addition, existing designs of the shear key primarily emphasize resistant capacity but overlook resilience. This study introduces a new sliding, modular, adaptive, replaceable, and two-dimensional (SMART) shear key designed to enhance the resilience of I-girder highway bridges. The SMART shear key has three primary goals: 1) enabling the rapid …

Positive Effects Of Sulfates On Performance Of Cement Paste Incorporating Low-Grade, High-Aluminum Steel Slag, Nannan Zhang, Gao Deng, Wenyu Liao, Chuanlin Hu, Hongyan Ma

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Steel slag with high aluminum (Al) content significantly delays the early hydration of cement when used as a supplementary cementitious material (SCM). To address this challenge, this study investigates the effects of gypsum (Gy) and sodium sulfate (SS) additions on the performance of cement pastes with 30 % high-Al ladle metallurgy furnace (LMF) slag. The mechanical properties, hydration kinetics, phase evolution, as well as the early-age hydration mechanism were explored. The results indicate that C3S hydration is substantially inhibited under high-Al conditions, mainly attributed to the rapid dissolution and reaction of reactive aluminates (particularly mayenite) in the slag. Both Gy …

The Fate Of Intra- And Extracellular Antibiotic Resistance Genes Through Advanced Wastewater Treatment Process, Celestene Adrianne Sebag

Graduate Theses and Dissertations

More areas across the globe are becoming affected by water stress or water scarcity. The decrease in available freshwater due to overconsumption reveals the direct need to consider other sources for necessities such as drinking water or food production. Agricultural irrigation uses 70% of the world’s freshwater, making the focus on safe and reliable reclaimed water for agricultural reuse imperative. However, contaminants of emerging concern (CECs), such as antibiotics and their resulting antibiotic resistance genes (ARGs), can spread and affect human health if reclaimed water is not treated to the proper level. Antibiotics are widely used in human medicine and …

Amorphous Sio2-Stabilized High-Valent Iron-Oxo Complexes Derived From Fe- And Si-Rich Solid Wastes For Efficient Tetracycline Hydrochloride Degradation, Cuirong Yan, Hongyan Ma, Xiunan Cai, Zhongqiu Luo, Jinyu Shi, Wenhao Li, Xintao Zhou

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

High-valent iron-oxo complexes show promise as green oxidants for water remediation but suffer from critical limitations in stability and pH adaptability. Herein, we report a facile method to synthesize amorphous SiO₂-stabilized high-valent iron-oxo complexes via Na⁺ diffusion activation of iron/silicon-rich copper smelting slag. In the complex, the synergistic coexistence of two distinct silica‑oxygen tetrahedral configurations-basic Na₂SiO₃ and acidic SiO2 oxides establishes a self-regulating pH buffering system that stabilizes solution neutrality. This unique structural design ensures sustained oxidative activity of the complex, representing a significant advancement over conventional silica-supported catalysts due to its intrinsic acid-base …

Data-Driven Shear Capacity Prediction Of Studs Embedded In Uhpc For Steel-Uhpc Composite Structures, Yanping Zhu, Woubishet Zewdu Taffese, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study employs ensemble learning algorithms to accurately predict the shear capacity of studs embedded in ultrahigh performance concrete (UHPC), a critical aspect of structural engineering. Using a comprehensive data set featuring six UHPC slab features, seven stud features, and one shear pocket feature, 35 ensemble models are developed across five cases and seven algorithms (bagging, random forest, AdaBoost, gradient boosting, XGBoost, CatBoost, and LightGBM). The Shapley additive explanations (SHAP) analysis is conducted on the top-performing models to gain insights into their decision-making mechanisms. Results indicate that transforming UHPC slab geometry parameters into a volume, alongside different diameter ratios, proves …

Hybrid Forecasting Of University Electricity Demand Using Time Series And Deep Learning, Minsoo Baek, Youngguk Seo

Faculty Articles

University buildings are energy-intensive and operate on complex schedules, making electricity demand forecasting particularly challenging. This study develops and evaluates monthly forecasting models for a public university campus in Georgia using six years of data (January 2019–December 2024) that integrate weather variables and academic calendar indicators. Three modeling approaches are compared: Seasonal Autoregressive Integrated Moving Average (SARIMA), SARIMA with exogenous variables (SARIMAX), and a hybrid SARIMAX–Long Short-Term Memory (LSTM) model. Feature selection methods, correlation analysis, Granger causality, Random Forest importance, Recursive Feature Elimination (RFE), and Least Absolute Shrinkage and Selection Operator (LASSO) regression, were applied to optimize input relevance. The …

Acoustic Emission Sensing For Assessing Compressive Strain In Impacted Thermoplastic Composites, M. M. Shahzamanian, Li Ai, Sydney Houck, Md Mushfiqur Rahman Fahim, Sourav Banerjee, Paul Ziehl

Civil Engineering Faculty Publications

Composite materials used in aircraft during in-flight service are vulnerable to impacts, which can lead to undetected damage and deterioration. Impact incidents can cause considerable structural harm that might not be immediately apparent, resulting in a decline in the mechanical properties of material and overall performance. There are currently limited advanced models capable of assessing the state of compressive strain (or stress) in a compression after impact (CAI) test based on acoustic emission (AE) data. Developing such a model may enable real-time monitoring and evaluation during in-flight service, providing users with alerts when composite material failure is approaching. This paper …

The Application Of Vetiver Grass In Natural Disaster Mitigation And Environmental Protection In Vietnam: A Bibliometric Analysis And Literature Review, Truc Phan, Tan Nguyen, Thang Pham, Bich T. Luong, Huong Nguyen

Civil Engineering Faculty Publications

Vetiver grass (Vetiveria zizanioides or Chrysopogon zizanioides) is a versatile tropical plant widely recognized for its applications in environmental protection and natural disaster mitigation. In Vietnam, where natural disasters such as floods and landslides are frequent, particularly along highways, Vetiver grass has proven to be an effective bioengineering solution. This paper provides a comprehensive review of the applications and benefits of Vetiver grass in preventing soil erosion and stabilizing slopes along Vietnam’s transportation systems. A bibliometric analysis of 555 Scopus-indexed publications (2000 – 2024) was conducted using VOSviewer software to identify research trends, key themes, and knowledge gaps. The findings …

Long-Term Degradation Of Natural-Fiber Coir Turf Reinforcement Mat Installed Along An Urban Stream In South Carolina, Kayden G. Rothery, Bob L. Lowe

Research from the Berry Summer Thesis Institute, 2025

Nature-based (or “living”) solutions to shoreline restoration are attractive due to their positive contributions to ecosystem function and service provision in coastal and estuarine environments. However, non-biodegradable plastics are widely used in their implementation; for instance, plastic-based geotextile fabrics are used to stabilize soil and organic matter to prevent loss of sediment fill. Paradoxically, these polymer-based geotextiles intended to protect the estuarine environment are unintended sources of plastic pollution as they inevitably degrade over time. Consequently, there is significant interest in transitioning from synthetic polymer-based geotextiles to sustainable non-plastic alternatives. To begin addressing this compelling research opportunity, this project aims …

Planning And Policy For Safer Roads With Autonomous Vehicles: Moral Decision Making Behavior In Dilemma-Inducing Situations, Fatemeh Nazari, Mohamadhossein Noruzoliaee

Civil Engineering Faculty Publications

This study develops a Dynamic Bayesian Network (DBN) framework to examine how public confidence in autonomous vehicle (AV) safety and willingness-to-ride respond to policy interventions in crash-imminent pedestrian–passenger prioritization scenarios. Using stated preferences survey data from San Francisco (SF) and San Antonio (SA), the model integrates baseline attitudes, socio-demographic factors, and policy conditions to simulate both intra-slice and inter-slice dependencies. Results from empirical-mix simulations indicate that SF respondents, despite having higher baseline confidence and willingness-to-ride, exhibit greater sensitivity to policies prioritizing pedestrians, with significant declines across all scenarios. By contrast, SA respondents show comparatively stable and modestly positive shifts, particularly …

Structural Response Of Rc Columns Strengthened Using Bfrp Based Bfegc System – Under Fire And Cooling Regime, Ruba P

Theses and Dissertations

Retrofitting fire-damaged columns is essential for restoring structural integrity. This study evaluates the effectiveness of BFRP based Basalt fiber Engineered Geopolymer Composites (BFEGC). The performance of basalt fiber wrapping and BFEGC was tested for fire protection system and retrofitted system. An optimal BFEGC mix achieved a compressive strength of 55.34 MPa, with split tensile strength, flexural strength, and strain hardening behaviour of 15.5 MPa, 5.13 MPa, and 6% respectively.

Microstructural analysis was accessed for the optimum mix. Durability tests include water absorption, sorptivity, and RCPT which confirmed compliance with standards. Thermo gravimetry analysis (TGA) shows the minimal weight loss of …

Impact Of Ionic Liquids On The Treatment Of Various Derivatives Of Prosopis Juliflora For Removing Toxic Pollutants From Wastewater, Karthikeyan A

Theses and Dissertations

Water resources are increasingly contaminated by toxic pollutants, particularly industrial effluents, posing significant environmental concerns. Addressing the toxicity of these pollutants, especially those released from textile industries, presents challenges due to their harmful effects on living organisms. Various treatment methods are employed to mitigate this issue, including coagulation, flocculation, membrane filtration, photocatalytic degradation, adsorption, anaerobic processes, and chemical oxidation. Among these, adsorption emerges as an effective and economical method due to its minimal secondary contamination, negligible sludge production, and the use of inexpensive agricultural and marine waste materials.

This study examines the ability of Prosopis juliflora treated with imidazolium-based ionic …

Effects Of Eogo In Metakaolin-Based Geopolymer, Chaewon Lee, Hoyoung Lee, Jinwoo An, Boo Hyun Nam

Civil Engineering Faculty Publications

Geopolymer concrete uses a geopolymer binder instead of traditional Portland cement; thus, it reduces carbon emissions by a significant amount. In this study, Edge-Oxidized Graphene Oxide (EOGO), a carbon-based nanomaterial, was added into a metakaolin-based geopolymer, and its effect on the mechanical and rheological properties of the mixture was investigated. EOGO was added into the mixture at 0% (control), 0.1%, 0.5%, and 1% of the metakaolin mass. Several experiments were conducted to characterize the properties of the metakaolin–EOGO (MKGO) geopolymer, including its compressive strength, free–free resonance column (FFRC), void content, water absorption, setting time, flow, and rheology. It was found …

Development Of An Access Charge Framework For High-Speed Rail Incorporating Rail Replacement Costs And Dynamic Train Characteristics, Nitesh Kumar Yadav

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis develops a framework to determine track access charges for shared high-speed rail corridors, with a focus on rail replacement cost driven by train-induced loads. The method explicitly accounts for both static loads, resulting from axle weights, and dynamic loads that arise from train speed and track geometry, particularly curvature. Train characteristics such as axle load, operating speed, frequency of service, and number of wheels are integrated with track parameters, including curve radius, to calculate the total vertical load. These loads are used to estimate the cumulative tonnage threshold for rail replacement and the resulting service life of the …

Career: Flavones As Safe, Sustainable Additives To Tune Biodegradable Plastic Stability, Kyle Moor

Funded Research Records

No abstract provided.

Thermo-Mechanical Advancements For Very High Strength And Ultra High Performance Concretes, Lana Grayson Brown Sisung

Theses and Dissertations

Interest in the use of high-strength concrete (HSC) has increased in recent years with demand for improved concrete performance. HSCs are widely associated with high heat of hydration and elusive behavior when exposed to high temperatures commonly occurring in mass structures. The optimization of HSC mixture proportioning is difficult due to a wide variety of constituents that influence thermal and mechanical properties. Additionally, determining in-place properties of mass concrete placements is elusive, and there are currently minimal to no test methods available that are both predictive and a direct measurement of mechanical properties. The objective of this dissertation is to …