Structural Engineering Commons^™

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.

Ftir Characterization Of Asphalt Sara Fractions In Response To Rubber Modification, Mohyeldin Ragab, Eslam Deef-Allah, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Asphalt–rubber binders (A-RBs) have a long and deep history of use; however, little is known regarding the interrelated chemical behaviors and miscibility of rubber with the asphalt fractions [saturates, aromatics, resins, and asphaltenes (SARA)]. This study comprehensively attempted to address this knowledge deficiency by employing Fourier transform infrared spectroscopy (FTIR) to investigate the chemical evolution of A-RBs. A-RB interacted at 190 °C and 3000 min⁻¹ for 8 h was deemed to have the optimal rheological performance. FTIR of the liquid fractions of A-RB 190–3000 showed a prominent chemical shift in the SARA fractions, with new peaks that showed rubber …

Machine Learning-Based Prediction Of Load Capacity In Corrugated Concrete-Filled Double Skin Tubes Under Axial Load, Aya Mohsen Handousa Mansoura University, Fikry Salem, Nabil Mahmoud Mahmoud, Mohamed Ghannam

Journal of Engineering Research

Concrete-filled double-skin steel tubular (CFDST) columns have become widely utilized in building construction and bridges, thanks to their exceptional structural capabilities. This study investigates the axial compression behavior of corrugated CFDST columns, analyzing the impact of flat or corrugated external/internal plates and varying internal steel tube widths. Furthermore, basic regression analysis fails to precisely forecast the complicated relation between the column properties and their compressive strength. To overcome these challenges, this study suggests two machine learning (ML) models, including the Gaussian process (GPR) and the extreme gradient boosting model (XGBoost). To estimate their strength, these models employ a range of …

A Comprehensive Review Of Carbonation In Supplementary Cementitious Concrete: Factors Affecting, Measurement Methods, And Challenges, Mariam Farouk Ghazy, Metwally Abd Allah Abd Elaty, Esraa Samir Abdeljalil

Journal of Engineering Research

Abstract-After water, concrete is the most widely used material on the planet. Accelerated carbonation treatment is an effective approach of reducing carbon emission in the concrete industry. Such carbonation process converts gaseous CO2 into carbonated minerals. This review provided a special focus on internal and external variables affecting carbonation depth. Internal variables such as mixture components, External variables such as adding pozzolanic materials such as fly ash, and slag were examined systematically, temperature, pressure, and CO2 concentration. The effect of accelerated carbonation curing on the compressive strength of concrete at early ages, both positive and negative influences were identified. …

Structural Performance Of Corrugated Steel Plate Shear Walls, Eyad Ayman Bakry, M. F. Hassanein, Ayman Seleemah

Journal of Engineering Research

Abstract- Corrugated Steel Plate Shear Walls (CoSW) represent a groundbreaking advancement in structural engineering, providing exceptional seismic resilience, energy dissipation, and lateral stiffness compared to traditional flat steel plate shear walls. This paper offers a comprehensive review of CoSW performance under various conditions, including cyclic and seismic loads, with a focus on enhancing geometric configurations and reinforcement techniques. Key innovations such as enhanced corrugation angles, stiffener integration, and strategically designed openings are discussed. Recent progress in computational modeling and experimental validation has further refined design methodologies, ensuring their practical applicability. The review highlights that critical parameters such as corrugation depth, …

Numerical Investigation Of Thermal Effects On Concrete Bridges: Insights From Frame And Shell Modeling, Mohamed Ibrahim Metwally Dr., Mohamed A. El Zareef Prof.

Journal of Engineering Research

Bridges are essential structural components of transportation networks, and their performance is significantly influenced by temperature variations. Thermal expansion and contraction can induce stresses that affect structural stability, necessitating accurate modeling techniques for design and maintenance. This study investigates the thermal behavior of a three-span continuous box girder bridge using two different numerical modeling approaches: the Frame Element model and the Shell Element model. The research evaluates the effects of uniform temperature conditions (20°C) and a temperature gradient of ±5°C, focusing on bending moments, normal forces, and fiber stresses. Results indicate that the Shell Element model predicts bending moments and …

Finite Element Modeling Of Newly Developed Cold-Formed Hollow Flanged Z-Beams, Mohammed Ahmed Diab, Mohamed Saeed Refaey, Hanan Eltobgy

Journal of Engineering Research

Cold-formed hollow flanged sections (CFHFS) are considered an innovative advancement in cold-formed steel design. These sections offer large lateral torsional rigidity over the open cold-formed section resulting in enhanced flexural capacity. This paper introduces a numerical study on the section moment capacity of newly developed cold-formed hollow flanged Z-beams (CFHFZBs). CFHFZBs can be easily constructed in the Egyptian market by welding an industrially available main Z-element to two secondary Z-elements to form the hollow flange. This paper presents the finite element modeling of sixteen CFHFZBs in a four-point bending arrangement using ABAQUS software. To obtain verified finite element models (FEMs), …

Investigating The Properties Of Eco-Bricks Composed Of Sawdust, Bamboo, And Varying Composition Of Sugarcane Bagasse Ash And Portland Cement, Wilfred Victor C. Marasigan, Julia Sophia Antonia S. Encarnacion, Czyrus Michael A. Bajeta, Alijah F. Gonzales, Juan Carlo T. Gumangan

Sinaya: A Philippine Journal for Senior High School Teachers and Students

With the construction industry contributing nearly 40% of global greenhouse gas emissions, there is a growing need for innovative and sustainable building materials. This research investigates a new eco-friendly concrete brick incorporating sugarcane bagasse ash (SCBA), sawdust, and bamboo fibers. Three eco-brick mixtures, each containing 2% bamboo fiber and 10% sawdust by weight but with varying proportions of Portland cement (PC) and SCBA, were tested against a standard brick for compressive strength, flexural strength, and water absorption. The optimal mixture, with 2% bamboo fiber by weight, 10% sawdust by weight, 85% PC, and 15% SCBA, exhibits compressive and flexural strength …

An Llm Approach For Automating The Analysis Of Bim (Ifc) Data, Miral Selim

Theses and Dissertations

This thesis introduces a novel methodology for automating the analysis of Building Information Modeling (BIM) data using LangGraph, an advanced extension of the LangChain framework, and integrating Google’s Gemini Large Language Model (LLM) with IfcOpenShell. BIM, and specifically Industry Foundation Class (IFC) files, are widely used in the construction industry for representing and managing building data. However, analyzing this data effectively remains a significant challenge due to its volume and complexity. Additionally, analyzing BIM data typically requires knowledge of different BIM software depending on the application. This research addresses this challenge by creating a workflow that utilizes LangGraph’s ability to …

Treatment And Activation Effects On Kaolinite-Based Earth Concrete, Mojtaba Kohandelnia, Maroua Zerzouri, Ammar Yahia, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Self-consolidating earth concrete (SCEC) addresses the long construction process of conventional earthen constructions and their structural limitations, while further efforts are needed to enhance its sustainability. This study explores the development of a kaolinite-based self-consolidating earth paste (SCEP) due to their blended powder system, incorporating raw and treated (calcined and ground-calcined) kaolinite under various activation techniques, such as water hydration, sodium hexametaphosphate (NaHMP), and sodium hydroxide (NaOH) activation. The synergistic effect of calcination and mechanosynthesis on rheological, mechanical, structural, and microstructural properties of SCEP were investigated. Mechanically treated kaolinite increased yield stress, plastic viscosity, storage modulus evolution, and build-up index, …

Caed Shop Entrance Wall Redesign, Ellen Elizabeth Untalan, Joelle Schalesky, Katherine Evalyn Timbes

Architectural Engineering: Graduate Reports

This project involved the replacement and redesign of the north wall at the CAED Support Shop at Cal Poly, San Luis Obispo. The redesign aligned the wall with the adjacent Engineering West building. The original concrete wall was designed with jagged recesses to accommodate large trash bins. These recesses no longer serve their intended function due to the permanent relocation of these bins. The replacement CMU low lift grouted wall optimizes courtyard space, enhances aesthetic cohesion, and maintains architectural features consistent with the existing structure. The following report outlines the process necessary to complete this project, including the permitting process, …

Statistical Time-History Response Of Mid-Story Isolated Structures In Linearized Elastic Conditions, Min Thit Khant

Master's Theses

This study presents a statistical analysis of the seismic demand of mid-story isolated structures in linearized elastic conditions. The assumed earthquake database consists of 228 ground motions recorded in California from earthquakes with magnitudes greater than 6. A three-degree-of-freedom modeling approach is adopted, and the seismic demands of the substructure, superstructure, and isolation system are determined for varying isolated mass and stiffness ratios. The seismic demand of mid-story isolated structures at the isolation level is expressed in terms of the response of an idealized isolated superstructure supposed to be on the ground, while the demands on the substructure and superstructure …

Experimental Characterization And Finite Element Analysis Of The Effects Of Pitting Corrosion On The Mechanical Properties Of Stainless Steel, Duncan Jay Fure, Long Wang

Master's Theses

Many structures do not fail from poor design, but instead from environmental degradation. Corrosion is one mode whose effects can be diminished, but not eliminated, by employing corrosion resistant materials, such as 304 stainless steel, which are still subject to pitting corrosion. Pitting corrosion is a chemical process of the localized removal of material leaving cavities. Despite the prevalence of pitting corrosion, there has been limited testing conducted of the effect of stress during corrosion. This study conducted accelerated controlled corrosion experiments with and without mechanical loading and various corrosion times. Pit morphology of different conditions was analyzed with statistical …

Evaluation Of Damages And Economic Losses In Light-Frame Timber Houses, Mason P. Leonard

Master's Theses

This thesis aims to evaluate the damages and economic losses in light-frame timber houses by designing and constructing a two-story, full-scale, fully equipped, code conforming timber assembly. Specifically, the structure will be analyzed based on how the non-structural components (NSC) like gypsum wallboard, interior doors, windows, and sliding patio doors as well as structural components like light-frame timber shear walls impact the economic losses.

Damage limit states were obtained from the Federal Emergency Management Agency (FEMA) P-58, Performance Assessment of Buildings to extract at what inter-story drift (ISD) ratio each damage limit state was expected to occur at. Fragility and …

Tettoia Iperbolica, Lydia Chou, Jack L. Walsh, William Jasper Mors, Simarjot S. Gandhoke, Ian F. Da Silva, Jamie L. Zimmerman

Architectural Engineering

Tettoia Iperbolica (Hyperbolic Canopy) is a multidisciplinary senior project created to revitalize an underutilized outdoor space next to the Architectural Engineering Building 21 at Cal Poly. The project responds to needs identified by faculty and staff, including limited gathering space, inadequate shading for the adjacent conference room, poor drainage, and a lack of ADA accessibility. Building on two previous senior project efforts, the 2025 team advanced the concept into a fully designed, structurally stamped, permitted redwood canopy supported by existing concrete columns and one new steel column.

The work included extensive site investigation to verify subsurface conditions, concrete strength testing, …

The Xenaform, Cassadie J. Golding

Architectural Engineering

The XenaForm explores how complex, expressive structures can emerge from simple, low-tech construction methods using principles of parametric design and structural geometry. By combining folded plate techniques with modular tetrahedral components, the project bridges high-tech digital modeling and hands-on physical fabrication. The result is a lightweight, buildable system that reclaims the engineer’s role as a form-finder.

Architectural Engineering Institute: International Student Design Competition 2025, Alexandra Marie Kersting, Alec Thomas Gibbs, Haley Francesca Sousa, Kline Genevieve Nickel

Architectural Engineering

The AEI International Student Design Competition is an annual competition held by the Architectural Engineering Institute that aims to replicate an integrated building design process. The 2025 Cal Poly team consisted of 4 Architectural Engineering students, each competing in the Structural and Integration disciplines. The team was provided a set of architectural drawings and a 3D architectural Revit model of Carson Headquarters in Omaha, Nebraska. The team was tasked with the creation of a complete structural design as well as a discussion of integration of other building design disciplines.

Microstructural Evolution And Rheological Enhancement Of Asphalt–Rubber Binders: Unveiling The Role Of Morphology In Performance, Eslam Deef-Allah, Mohyeldin Ragab, Mohamed Attia, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Understanding the development of an asphalt binder's internal network structure is essential when interacting asphalt and crumb rubber. Thus, the focus of this study was to reveal the development of asphalt–rubber binders' (A-RBs) network structures at different interaction times and their correlation with performance. Atomic force microscopy (AFM) was utilized to image the morphologies of the binders, and the binders' performances were explored rheologically with a dynamic shear rheometer. Extending the interaction time to 8 h and utilizing a soft binder altered the network structures from agglomerated dispersoids—minuscule distributed phase zones embedded in the continuous matrix of the asphalt binder—to …

Comparative Analysis Of Lab-Data-Driven Models For International Friction Index Prediction In High Friction Surface Treatment (Hfst), Alireza Roshan, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

High Friction Surface Treatments (HFSTs) are often utilized as a spot treatment to enhance selected areas with high friction demand rather than extended pavement sections and are helpful in increasing skid resistance and minimizing road accidents. A laboratory design approach was created to assess the fundamental ideas behind the international friction index (IFI) concept and update the present IFI model parameters for HFST applications based on test findings to gain a better understanding of HFST performance. Two aggregate types in three sizes were tested under controlled polishing cycles. Friction and texture were measured using the Dynamic Friction Tester (DFT) and …

Fire Fossils: Biomineral Infrastructures In Untangling Climates, Tanmayee More

Masters Theses

Diatoms drift, sediments sink, wildfires generate their own weather. Lightning strikes can blast sand into glass, and microscopic organisms do the same in the cold recesses of the ocean. What alchemies and metabolisms catalyze space, time, and energy? What are the thermodynamics of infrastructure in Climate Change?

Places, materials, and beings are afterimages. Through alchemical experiments, and multi-scalar imaging, I develop simulations of wildfires, and their profound, reverberating effects. In this thesis, a glass-meets-landscape experimental process enters these obscured conditions and renders new material relations for the built environment.