Civil Engineering Commons^™

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 …

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 …

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 …

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 …

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 …

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 …

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 …

Stabilization Of Cr³⁺ Using Iron Rich Slag-Derived Phosphate Cement: An Integrated Solution For Heavy Metals And Hazardous Solid Wastes, Ting Huang, Hongyan Ma, Zhongqiu Luo, Xintao Zhou, Zhengqing He, Peiwen Lv, Xiunan Cai, Pingyan Wang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A novel iron-based phosphate cement (IPC), derived from iron-rich smelting slag (ISS), was developed as a sustainable and efficient binder for the stabilization/solidification of trivalent chromium (Cr³⁺). The mechanical properties, hydration behavior, microstructure, leaching toxicity, chromium chemical forms, and environmental safety of chromium-stabilized iron phosphate cement (CIPC) were thoroughly evaluated. The results showed that, with a mass ratio of ISS to ammonium dihydrogen phosphate (ADP) of 2.0, and even with the addition of 20 % chromium nitrate nonahydrate (CN), the compressive strength of CIPC reached 4.2 MPa after curing for 28 d. Furthermore, chromium leaching was well below …

Influence Of Mixing Duration And Absorption Characteristics Of Superabsorbent Polymers On The Fresh And Hardened Properties Of High-Performance Concrete, Yu Cun Gu, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study investigates the combined influence of superabsorbent polymers (SAPs) with distinct absorption kinetics and extended mixing sequences on the rheological, mechanical, and transport properties of high-performance concrete (HPC). Two SAPs—an ionic acrylamide-co-acrylic acid copolymer (SAP-P) and a non-ionic acrylamide polymer (SAP-B)—were incorporated at an internal curing level of 100%. The impact of extended mixing times (3, 5, and 7 min) following SAP addition was systematically evaluated. Results showed that longer mixing durations led to increased superplasticizer demand and higher plastic viscosity due to continued water absorption by SAPs. However, yield stress remained relatively stable owing to the dispersing effect …

Comparative Study On The Long-Term Performance Of Bmd Mixtures Prepared Using Different Sample Preparation Techniques And Superpave Mixtures Under Varying Pavement Structures, Amarjeet Tiwari

Graduate Theses and Dissertations

Asphalt mix design has advanced significantly since the 1930s, with Balanced Mix Design (BMD) emerging to address durability concerns found in the Superpave method by optimizing binder content based on performance criteria. The performance of bituminous mixtures can be assessed through laboratory testing. These tests require proper sample preparation, and various techniques are employed for this purpose. Understanding the differences between these techniques is essential for the successful application of bituminous mixtures in the field. The objective of this study is to assess the differences in the predicted long-term performance of two sample preparation techniques, Lab Mix Lab Compacted (LMLC) …

Coupling Effect Of Abrasion And Erosion On Ultrahigh-Performance Seawater-Sea Sand Concrete, Dawei Ding, Wei Zhang, Lanqin Wang, Hongyan Ma, Biqin Dong, Song Han, Hongjian Xu, Dongshuai Hou

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Preparing ultrahigh-performance seawater-sea sand concrete (UHPSSC) to mitigate the scarcity of freshwater and river sand resources has generated considerable recent research interest. However, the deterioration mechanisms of UHPSSC under the effect of abrasion and erosion remain unstudied. In this paper, the underwater steel ball method was conducted to evaluate the impact of seawater, sea sand, steel fiber, and seawater abrasion on the abrasion resistance of UHPSSC. Then the stress erosion models of calcium-silicate-hydrate (C-S-H) were constructed to investigate the degradation mechanisms of UHPSSC under the effect of external stress and seawater erosion. The results show that the application of seawater …