Structural Engineering Commons^™

Downdrag Defeated – The Neutral Plane Method, Kyle L. Zak, Min Sang Lee

Civil Engineering Professional Development Seminar

The neutral plane method for evaluating downdrag on deep foundations has been gaining popularity over the past few years. It is a powerful tool that, in many situations, can all but eliminate downdrag concerns on deep foundations. INDOT has allowed its use recently and adapted its forms to accommodate this method. The presentation will cover the theory behind the method and how it can be applied in bridge design. We will then demonstrate how to incorporate the method into the INDOT workflow, and we’ll show a couple real-life examples where the neutral plane method saved the day.

Mass Timber Construction: Products, Performance And Design, Anthony Harvey

Civil Engineering Professional Development Seminar

Due to their high strength, dimensional stability and positive environmental performance, mass timber building products are quickly becoming materials of choice for sustainably‐minded designers. This presentation will provide a detailed look at the variety of mass timber products available, including glue‐laminated timber (glulam), cross laminated timber (CLT), nail laminated timber (NLT), heavy timber decking, and other engineered and composite systems. Applications for the use of these products under modern building codes will be discussed, and examples of their use in U.S. projects reviewed. Mass timber’s ability to act as both structure and exposed finish will also be highlighted, as will …

Comparative Study Of Interfacial Bond Strength Of Steel H-Pile With Ultra-High Performance And Polymer Concrete Jacket, Binod Shrestha, Mohanad M. Abdulazeez, Mohamed A. Elgawady

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study investigates the bond behavior of steel H-pile encased in concrete jackets under push-out loading, considering the effects of concrete type and embedment length. Nine full-scale specimens were tested using three concrete types: ultra-high-performance concrete (UHPC), Methyl Methacrylate Polymer Concrete (MMA-PC), and conventional concrete (CC), with embedment lengths of 63.5 mm, 127 mm, and 190.5 mm. The experimental results revealed that MMA-PC jacket demonstrated the highest bond strength, though gains were marginal beyond 127 mm. UHPC exhibited superior tensile strength and ductility, preventing splitting failure. UHPC also displayed the highest interfacial fracture energy of 9.63 N/mm, exceeding MMA-PC and …

From The Editors, Rully Karim Dr.

Journal of Project Management & Construction

The Journal of Project Management and Construction (JPMC) is a peer-reviewed publication dedicated to advancing the field of project management and construction, grounded in the principles outlined in the PMBOK 6th Edition. Our focus encompasses the ten knowledge areas essential to successful project management: Integration, Scope, Schedule, Cost, Quality, Resource, Communications, Risk, Procurement, and Stakeholder Management.

JPMC publishes original research papers written in English that provide deeper insights into these knowledge areas and contribute to the development of best practices in project management and construction. Submissions may include theoretical analyses, computational models, experimental observations, or a combination of both theoretical …

The Impact Of Relative Bridge Width On Highway Crashes In Nebraska, Mujahid Ali Bahadur

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

This research examines how bridge width relative to the approach roadway affects crash occurrence on Nebraska highways. The Nebraska Department of Transportation-(NDOT) Bridge Design Manual sets minimum bridge widths based on roadway classification, traffic projections, and the American Association of State Highway and Transportation Officials’ (AASHTO) Load and Resistance Factor Design (LRFD) criteria. While these guidelines ensure structural and functional adequacy, they do not incorporate safety performance analyses based on crash data. This leaves an important gap in understanding how bridge and approach roadway width decisions influence safety outcomes.

This research has four objectives: (1) evaluate crash frequency across different …

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, …

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 …

Interfacial Shear Transfer Between Steel H-Piles And Concrete Encased In Cfrp, Mohanad M. Abdulazeez, Binod Shrestha, Mohamed A. Elgawady

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Numerous in-service steel H-piles, a common structural element in the bridge industry, suffer severe corrosion. One of the adopted solutions is to use concrete jackets to encase the corroded sections. Therefore, interfacial shear strength between the uncorroded section and the jacket is crucial. This paper presents an experimental investigation of the interfacial shear stresses of 18 full-scale H-piles encased in concrete jackets and subjected to push-out static testing. The concrete jackets are confined using different carbon fiber-reinforced polymer (CFRP) confinement ratios. Different cross-sectional areas and distributions of shear studs are investigated. The average and maximum bond stresses are evaluated and …

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 …

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 …

Failure Analysis Of Prestressed Concrete Girder Bridges Under Over-Height Truck Impacts, Mohamed T. Elshazli, Mohamed Elgawady, Tao Xing, Ahmed Ibrahim

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Accidental collisions between over-height trucks and bridge superstructures are a common threat to existing bridge infrastructure. These incidents often stem from illegal over-height vehicles or truck operators' unawareness of clearance limits, posing serious safety risks and causing substantial structural damage. This study presents a comprehensive numerical investigation of the dynamic response of prestressed concrete girder bridges subjected to over-height truck impacts. Large-scale finite element models were developed in LS-DYNA, with validation conducted against experimental results. The parametric study explored impact speeds ranging from 16 to 113 km/h (10 to 70 mph), impactor masses between 2 and 6 tons, impact locations, …

Understanding The Relationship Between Structural Failure And Fatalities In Tornadoes: A Quantitative Investigation Of The 2021 Midwest Tornado Outbreak, Yi Zhao, Ruwen Qin, John W. Van De Lindt, Justin Sharpe, Grace Yan

Engineering Management and Systems Engineering Faculty Research & Creative Works

During 1950-2011, the number of fatalities caused by tornadoes in the U.S. significantly exceeded the fatalities caused by both hurricanes and earthquakes. To reduce tornado induced fatalities, it is essential to understand how structures/building failures correlate with fatalities and who are more vulnerable to tornadoes. Insights from this study are intended to help provide information to decision-makers on where to allocate limited resources for enhancing tornado resilience. By examining both the fatality data and structural damage data in the 2021 Midwest Tornado Outbreak, the objective of this study is to examine the occurrence of fatalities during tornadoes across various types …

Detection Of Bacterial Genomic Dna Fragments Using The Mxene Crispr-Cas9 Field-Effect Transistor, Jiaoli Li, Ali Taheri, Weijia Liu, Ying Zhuo, Pengfei Ma, Chenglin Wu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Clustered regularly interspaced short palindromic repeats (CRISPR)-based field-effect transistor (FET) sensors provide a promising platform for highly specific and amplification-free nucleic acid detection. However, their direct application in identifying target sequences within intact genomic DNA remains underexplored. We developed a CRISPR-Cas9 FET sensor for detecting DNA sequences by immobilizing Cas9 onto a graphene-MXene sensing interface via (3-aminopropyl)triethoxysilane (APTES) functionalization. The sensor targeted Stx1, a 440 bp laboratory-amplified fragment associated with Shiga toxin production in pathogenic E. coli. Gel electrophoresis confirmed the precise cleavage of Stx1, while the nontarget sequence Stx2 remained undetected. FET measurements further validated the sensor's specificity, showing …

Structural Design Using Conditional-Gan Fused With Property Text Information: A Case For Masonry Structures, Arash Teymori Gharah Tapeh

All Dissertations

Structural design, by nature, is a complex process that requires a considerable amount of time, expertise, and knowledge. In such a process, the structural designer must navigate various codal provisions to crystallize a proper and adequate design. As the role of automation continues to shape the domain of structural engineering over the past few decades, a new front leverages artificial intelligence (AI). Currently, AI acts as a "copilot," collaborating to advance workflow speed and accelerate the design process. Among all the different collaborations between humans and AI, GANs (Generative Adversarial Networks) are seen to complement human creativity by automating specific …

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 …

Utilization Of Ftir-Atr For Material Characterization And Forensic Analysis, Helmut Leodarta, Ahmed S. El-Ashwah, Punyaslok Rath, Magdy Abdelrahman, William G. Buttlar

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The growing use of chemical modifiers and additives in asphalt mixtures necessitates a reliable system for their identification and quantification, crucial for quality control, assurance, and forensic investigations. Fourier Transform Infrared (FTIR) spectroscopy offers a cost-effective method by analyzing the interaction of infrared light with chemical groups, producing distinct spectral fingerprints. This study evaluates 44 materials, including binders, warm mix additives (WMAs), rejuvenators, release agents, and concrete admixtures. It also assesses the ability of FTIR testing to identify and quantify chemical changes and aging in asphalt binders with rejuvenator addition. An Attenuated Total Reflectance (ATR) accessory was employed for practical …

Data-Driven Prediction Of Binder Rheological Performance In Rap/Ras-Containing Asphalt Mixtures, Eslam Deef-Allah, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Asphalt recycling technologies have advanced considerably over the last few decades with the utilization of reclaimed asphalt pavements (RAP) and recycled asphalt shingles (RAS). Characterizing aged and heterogeneous binders in these mixtures is challenging, particularly with limited extracted binders. This study suggests a data-driven framework that considers the rheological, chemical, and thermal characteristics to predict the binders' performance. Ninety-seven mixtures with 0–35% of the asphalt binder replaced with RAP/RAS binders were included as cores from the field, plant-produced mixtures, and laboratory-fabricated mixtures. The binders were chemically quantified using aging, aromatic, and aliphatic indices. Thermal analyses of the binders involved the …

Geopolymer Clsm With Off-Specification Fly Ash And Bottom Ash: A Sustainable Approach To Hazardous Waste Utilization, Alexis K. Vandomelen, Ahmed A. Gheni, Eslam Gomaa, Mohamed A. Elgawady

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Conventional controlled low-strength material (CLSM) is a self-consolidating cementitious material with high flowability and low strength, traditionally composed of cement, sand, and water. This study explores the sustainable utilization of off-specification fly ash (OSFA) and bottom ash (BA), classified as industrial by-products with potential environmental hazards, to develop eco-friendly geopolymer CLSM as an alternative to conventional CLSM. Sodium hydroxide (NaOH) was used as an alkali activator to stabilize and solidify both two-part (liquid NaOH) and one-part (solid NaOH pellets) geopolymer CLSM mixtures. These mixtures were evaluated based on flowability (ASTM D6103-17) and compressive strength (< 300 psi per ACI Committee 229 guidelines for excavatability). A cost analysis was also conducted. The results demonstrated that incorporating OSFA as a cement replacement increased water demand by 15% to meet flowability requirements, while BA substitution for sand led to segregation challenges requiring mixture adjustments. For two-part mixtures, higher carbon content in OSFA necessitated an increased water-to-fly ash ratio. All self-consolidating mixtures exhibited 1-day compressive strengths ranging from 5 psi (0.03 MPa) to 87 psi (0.6 MPa). One-part mixtures showed a 1% to 34% reduction in 7-day compressive strength compared to two-part mixtures, improving excavatability. Increasing the BA-to-OSFA ratio from 1:1 to 3:1 reduced water demand due to lower surface area but increased the NaOH/OSFA ratio. This study highlights the potential of geopolymer CLSM to reduce costs by up to 94% at current NaOH prices (USD 6 per cubic yard) while repurposing hazardous industrial by-products, offering a cost-efficient, sustainable, and environmentally responsible solution for CLSM production.