Structural Engineering Commons^™

Improving The Concrete Compressive And Flexural Strength With A Low Fraction Addition Of Carboxylated Nitro-Oxidized Cellulose Nanofibrils From Banana Rachis, Ngesa Ezekiel Mushi, Emmanuel Kagya

Tanzania Journal of Science

Conventionally, concrete strength depends on the bonding interface, especially in hydrated products such as calcium silicate hydrate (CSH). As a result, concrete is sensitive to tensile load. With its unique properties, a low fraction of carboxylated nitro-oxidized cellulose nanofibrils (NOCNF) from the banana rachis is employed to improve the mechanical performance of the concrete nanostructurally. Compressive and flexural strength using the NOCNF content at 0, 0.05, and 0.1 wt.%, cured for 7 and 28 days, were evaluated. Notably, the compressive strength increased by 16 % and the flexural strength by 13 % at 0.1 wt.% NOCNF compared to plain concrete …

Ground To Roof Snow Load Ratio (Gr) Data Release, Brennan Bean, Cooper Nelson, Jesse Wheeler, Scout Jarman, Salam Adil Al-Rubaye, Marc Maguire

Browse all Datasets

This data release provides historical ground-to-roof snow load ratio (GR) datasets used for snow load research and model development. The release includes original referenced datasets, cleaned country specific datasets, and a master dataset that combines Canadian and United States datasets into a standardized format for research and engineering applications.

Wind Effects Induced By Multivortex Tornadoes On A Low-Rise Building, Yi Zhao, Guirong Yan, Tetsuya Takemi, John Van De Lindt

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Multivortex tornadoes contain two or more subvortices that orbit within a parent vortex and can generate highly intermittent and localized near-ground wind fields. This study investigates how tornado flow structure affects wind effects on a low-rise building using large-eddy simulations. One single-vortex tornado and three multivortex tornadoes with different subvortex configurations are examined by systematically varying swirl ratio. Tornado translation is modeled using a relative-motion framework in which the building traverses the vortex field. Aerodynamic force and moment coefficients are evaluated along the traversing path. Additional stationary simulations are conducted to examine repeated load amplification associated with subvortex passages. Compared …

Impact Of Climate Change On Extreme Windstorms And Implications For Structural Design In The United States, Teng Wu, Reda Snaiki, Frank Lombardo, Sihan Li, Michele Barbato, Guirong Yan, Robert J. Trapp

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Climate change impacts various extreme windstorms associated with specific meteorological phenomena in different ways. Because various windstorms contribute to the design wind speeds, this study systematically reviewed the state-of-the-art understanding of climate change effects on wind events that collectively contribute to structural wind design in North America, particularly the US, including extratropical cyclones (as well as nor'easters), tropical cyclones, thunderstorms, and tornadoes. For each windstorm type, the general evidence of climate change impacts on storm activities (e.g., occurrence frequency and intensity) are summarized, followed by the introduction of existing simulation frameworks for yearly (or subyearly) maximum storm winds under changing …

Five-State Seismic Damage Classification Of Steel-Girder Bridges On Soft Soil Using Directional Intensity Measures And Multi-Parameter Damage Indices, Ibrahim Alomari, Woubishet Zewdu Taffese, Mohammad Hossein Afsharmovahed, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Rapid yet accurate post-earthquake damage assessment of highway bridges is essential to ensure transportation network resilience. Traditional inspection, fragility analysis, and finite element modeling are time-consuming or inaccurate for real-time decision-making. This study compares ten machine-learning classifiers for the seismic damage states of highway steel-girder bridges that incorporate directional intensity measures to represent the variance of ground motions. Based on the nonlinear time-history analyses of two Missouri bridges, one Michigan bridge, and one Wisconsin bridge, multi-parameter structural damage indices were proposed and mapped to five damage states from none to collapse. Among ten supervised algorithms studied, the artificial neural network …

Effect Of Rheology Modification On Fiber Orientation And Dispersion In 3d-Printed Ultra-High-Performance Concrete, Haodao Li, Alfred Addai-Nimoh, Seongho Han, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The extrusion process in 3D concrete printing (3DCP) facilitates horizontal alignment of steel fibers along the printing direction, thus enhancing the load-bearing capacity of printed elements. However, such shear-induced fiber alignment is highly sensitive to rheological properties. This study investigates how variations in dynamic yield stress (τd) and plastic viscosity (μ), influence the extrudability, fiber orientation and dispersion, and anisotropic mechanical behavior of ultra-high-performance concrete (UHPC). Five viscosity-modifying agent (VMA) types were incorporated at two content levels to modify the rheology of printable UHPC. Results showed that moderate VMA additions improved printability, whereas excessive contents markedly increased τd and μ; …

Expected Structural Damage, Residual Capacity, And Repairability Of Light-Frame Timber Houses, Mikayla Caruthers

Master's Theses

Earthquake damage in light-frame timber structures is commonly evaluated using peak inter-story drift. However, drift alone does not fully represent the remaining structural capacity of a building or its ability to be repaired following a seismic event. Although expected structural damage, residual capacity, and repairability have each been studied extensively, these concepts are often considered independently, leaving limited guidance that links them within a unified post-earthquake assessment methodology.

This thesis establishes an integrated framework that relates expected structural damage, residual capacity, and repairability for light-frame timber residential structures. Existing literature was synthesized to develop drift-based damage-state classifications, identify methods for …

Experimental Studies Of Compressive Strength Of Sustainable Concrete With Partial Cement Substitution Using Palm Oil Boiler Ash, Daral Suraedi, Jessica Sjah, Nuraziz Handika, Saffanah Fasya Aulia, Karmenita Olivia Edwardo

CSID Journal of Infrastructure Development

This study investigates the mechanical performance of sustainable concrete incorporating Palm Oil Boiler Ash (POBA) as a partial cement replacement. As the construction sector seeks to reduce CO₂ emissions and manage agro-industrial waste, POBA emerges as a promising supplementary cementitious material due to its pozzolanic potential and abundance in palm oil–producing regions such as Indonesia.Concrete specimens were prepared with POBA substitution levels ranging from approximately 10% to 30% by weight of cement, in combination with nanosilica and a polycarboxylate ether (PCE) superplasticizer to enhance performance. The mix design was developed in accordance with ACI 211 guidelines to maintain comparable workability …

How Does Competitive Adsorption Between Vma And Pce Influence Yield Stress Of Cement Paste? A Novel Insight From Interparticle Forces And Percolation Threshold, Huamin Sun, Le Teng, Xiaohan Yu, Xin Shu, Zhangli Hu, Jiaping Liu, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Viscosity modifying admixture (VMA) and polycarboxylate superplasticizer (PCE) are often combined to optimize rheological properties of cement-based materials. However, the competitive adsorption of these complex admixtures can greatly influence rheological properties. Many studies have investigated the variation of yield stress due to competitive adsorption between VMA and PCE; but the mechanisms are not fully understood. This study aims to shed a new light on this question in cement paste systems prepared with low water-to-binder ratios of 0.16–0.30. The competitive adsorption of VMA and PCE was quantitatively assessed using the Total Organic Carbon and Ultraviolet-Visible Spectroscopy measurements. The effect of competitive …

A Machine-Learning-Based Systematic Framework For Modeling Compression And Recompression Indices For Florida Soils, Michael Morales

Doctoral Dissertations and Master's Theses

This thesis develops a machine-learning framework for estimating the compression index and the recompression index of Florida soils from routinely measured index properties, and reports two studies that build it. Consolidation settlement design requires both indices, and both are obtained from the incremental-loading oedometer test, which occupies a specimen for one to two weeks; the index tests that accompany it are complete within hours. Empirical correlations have filled that interval since the 1950s, but their coefficients are calibrated on specific soil populations and transfer poorly between regions. The first study analyzes 376 consolidation tests compiled for the Florida Department of …

Transforming Dredged Sediment Into Reactive Clay: Critical Review Of Calcination, Reactivity, And Sustainable Valorization As Supplementary Cementitious Material, Seongho Han, Sanghwon Wi, Koochul Ji, Keun Hyeok Yang, Farshad Rajabipour, Kamal H. Khayat, Jinyoung Yoon

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Dredged sediment (DS) is generated worldwide in large volumes through routine port and waterway maintenance, yet its disposal presents environmental and economic challenges. Recently, calcined dredged sediment (CDS) has emerged as a supplementary cementitious material (SCM), offering a viable alternative to traditional SCMs, such as fly ash and slag cement. This review synthesizes current knowledge on the physical, chemical, and mineralogical characteristics of raw DS and pretreatment strategies aimed at dewatering, organic matter removal, and contaminant stabilization. The effects of calcination on the production of reactive amorphous aluminosilicates are also discussed. Emphasis is placed on physicochemical changes revealed by experimental …

Low-Carbon Concrete For Sustainable Construction: A Comprehensive Review Of Performance Characteristics, Implementation Challenges, And Decarbonization Pathways, Fazel Azarhomayun, Jingjie Wei, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Reducing the carbon footprint of concrete has become a central objective in sustainable construction. Low-carbon concrete (LCC), developed primarily through clinker reduction, supplementary cementitious materials, and alternative binder strategies, offers a promising route for lowering embodied emissions while maintaining the performance requirements of structural concrete. This comprehensive review consolidates the current state of knowledge on LCC, identifies critical research and implementation gaps, and examines its material composition, mixture-design methodologies, performance characteristics, structural applications, implementation challenges, and decarbonization pathways. Single-SCM systems have been reported at clinker-replacement levels approaching 50%, although durability at these replacement levels, particularly carbonation resistance, remains system- and …

Recent Advances In The Rheological Properties Of Ultra-High-Performance Concrete: A Critical Review, Le Teng, Kamal H. Khayat, Jiaping Liu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Ultra-high-performance concrete (UHPC) with adapted rheology continues to attract interest considering the requirement for novel processing techniques such as self-consolidating, pumping, spraying, and three-dimensional (3D) printing. The rheology of UHPC is complex due to its high solid volume fraction, low water content, and wide range of constituent materials that affect its flow properties. This work provides guidance for tailoring the mixture proportioning of UHPC to secure proper rheological properties and performance of UHPC for various applications. In the first part of this work, key physical, physicochemical, and chemical factors that can affect the rheological properties of UHPC are discussed. Rheological …

A Workflow For Automating Geospatial And Data Visualizations For Post-Earthquake Building Damage Data, Alejandra Bravo

Architectural Engineering: Graduate Reports

After major seismic events, reconnaissance efforts of various types are made to gather data. Coarse data can be collected with satellite imagery, mid-scale data can be recorded by capturing thousands of images, and granular data is typically documented manually by humans. Post-earthquake reconnaissance teams can be deployed by universities, research organizations, professional associations, and private firms. Academics, engineers, and students with varying degrees of expertise are tasked with collecting building metadata and damage data, typically in a short period of time. This data can be of various types including numerical (i.e. number of stories, height, etc.), categorical (i.e. damage level, …

Matlab Shake Table Control And Data Acquisition System, Abigail Austin

Architectural Engineering

The College of Architecture and Environmental Design’s (CAED) seismic laboratory shake table is used for earthquake engineering education and experimental testing. However, the existing control system is outdated and difficult for students unfamiliar with the system to operate. The objective of this project was to develop a MATLAB-based control and data acquisition application to simplify shake table operation and improve accessibility, of both operation and output, for student users.

The developed application imports earthquake acceleration records, scales the input motions to the operational limits of the shake table, and executes the desires motion through the existing hardware system. Experimental data …

Reinforced Concrete Design Fundamentals, Belen Stephanie Martinez Espinoza, Estevan Jacob Perez

Architectural Engineering

Hispanic workers make up a large and growing portion of the construction workforce in the United States; particularly in California, the percentage of construction workers who are Hispanic is estimated to be about 55% as of 2021 (Elkins). Many of these workers are Spanish-speaking, yet there is still a gap between technical engineering design and what is understood and applied in the field. One major reason for this gap is the lack of clear bilingual resources. To bridge the gap, a 48-page bilingual booklet titled Reinforced Concrete Design Fundamentals (Fundamentos del Diseño de Concreto Reforzado in Spanish) was created. This …

Design And Construction Of Caed Support Shop Steel Fence On Existing Cmu Wall, Jared Gustavo Martinez, Agustin Dominguez Jimenez

Architectural Engineering

This project involved the design, testing, fabrication, and construction of a new steel fence system for the CAED support shop at California Polytechnic State University, San Luis Obispo. The fence was designed to attach to an existing CMU wall and serve as a future attachment point for a removable shade canopy system. Experimental testing was performed on multiple turnbuckles to establish a conservative design load for the structural design of the fence posts, baseplates, welds, and anchorage connections. In addition to meeting structural requirements, the project incorporated architectural elements inspired by the original fence and surrounding CAED shop environment. The …

Tanzania Mbesese Initiative 2026, June Ezzell, Sam Liebman, Noah Beyer, Kate Hamilton, Luke Vollert, Kylee Borgen, Cody Balazs, Meg Mclaughlin

Architectural Engineering

The Tanzania Mbesese Initiative 2026 Senior Project supports a multi-year design-build effort to establish the Same Polytechnic College in Same, Tanzania. This community faces high poverty levels and limited access to higher education, necessitating sustainable infrastructure to support tertiary education. To prepare for the upcoming July phase of construction, an eight-student Architectural Engineering team designed three practical and resilient structures: a Shade Structure, a Water Collection Structure, and a Reusable Scaffolding system. The final design applied structural analysis, modeling, and hand-tool fabrication practice to balance material efficiency with long-term structural durability. The deliverables provide comprehensive construction documentation, complete material takeoffs, …

Design And Implementation Of A Honeycomb Damping System For The 2026 Eeri Seismic Design Competition, Vera Nguyen, Lauryn Wojcik

Architectural Engineering

The authors of this report were a part of the 2026 Earthquake Engineering Research Institute (EERI) chapter at California Polytechnic State University, San Luis Obispo. In July 2026, they will travel to Portland, Oregon with 12 students to compete in the Undergraduate Seismic Design Competition hosted by EERI. The competition required teams to develop a comprehensive structural design proposal that included computer-based modeling and analysis, construction of three physical models, and the preparation of both a technical poster and oral presentation for a proposed high-rise building located in Portland, Oregon. Cal Poly’s “Illahee Tower” was designed with an emphasis on …

Strategies For Extending The Service Life Of Prestressed Concrete I-Shaped Beams, Sanjoy Kumar Bhowmik

Dissertations

Prestressed concrete (PSC) I-shaped beams are widely used in bridge construction because of their structural efficiency and durability. The service life of these beams is reduced and the maintenance frequency is increased due to the distress during fabrication and subsequent deterioration. Although several mitigation strategies have been proposed and implemented, beam end cracking during fabrication remains a major concern. The causes and mitigation strategies for beam end cracking have been studied for decades, but there have been no comprehensive studies utilizing beam end strains during fabrication and lifting at prefabrication plants under normal operational conditions. Moreover, existing maintenance and repair …