Structural Engineering Commons^™

Effect Of Latex Modified Concrete Overlays With Reduced Surface Preparation On The Load Distribution And Flexural Strength Of Channel Girders, Samuel Dodd

All Theses

This thesis investigates the use of a Latex Modified Concrete (LMC) overlay to increase the strength of prestressed channel girders and enhance their ability to distribute load. The research conducted in this thesis involved material testing of several different LMC mixes and flexural testing of an LMC overlay and girder system. The material testing was used to determine a reasonable LMC mix design and surface preparation method to be used for the overlay. Based on material testing it was concluded that a rapid-set mix and pressure washing of the girder surfaces were a reasonable mix design and surface preparation for …

Improved Vehicle-Bridge Interaction Modeling And Automation Of Bridge System Identification Techniques, Omar Abuodeh

All Dissertations

The Federal Highway Administration (FHWA) recognizes the necessity for cost-effective and practical system identification (SI) techniques within structural health monitoring (SHM) frameworks for asset management applications. Indirect health monitoring (IHM), a promising SHM approach, utilizes accelerometer-equipped vehicles to measure bridge modal properties (e.g., natural frequencies, damping ratios, mode shapes) through bridge vibration data to assess the bridge's condition. However, engineers and researchers often encounter noise from road roughness, environmental factors, and vehicular components in collected vehicle signals. This noise contaminates the vehicle signal with spurious modes corresponding to stochastic frequencies, impacting damage monitoring assessments. Thus, an efficient and reliable SI …

Experimental Investigation Of The Long-Term Bending Deflection And Creep Performance Of Cross-Laminated Timber (Clt), Aaron Desantis

All Theses

Rising popularity in mass timber construction for residential and commercial projects has escalated the need to develop and increase understanding of mass timber products both from a strength and serviceability perspective. For cross-laminated timber (CLT) there is a significant lack of research on the creep characteristics also known as long-term deflection behavior. Creep is particularly important for products such as CLT that are used for floors with longer spans. Full-scale creep testing was conducted using 5-ply CLT panels over the course of 6 months in a controlled environment under dry service condition. Testing resulted in average final deflections 1.73 times …

Effect Of Transverse Post-Tensioning On Moment Distribution Between Channel Girders, William Eubanks

All Theses

This thesis investigates the strength of prestressed concrete channel girders used

in bridges in South Carolina and how to improve their load distribution. The specimens

are 30 feet in length, 33 inches wide and 17 inches deep. South Carolina has 377 bridges

containing prestressed concrete channel girders and many of these bridges received a

poor load rating in a recent load rating project conducted by the South Carolina

Department of Transportation (SCDOT). The research included flexural testing of seven

individual channel girders and load distribution tests of three transversely post-tensioned

channel girders. Individual flexural testing was done to determine the …

Vibration Fatigue Of Leaded Solder Joint Interconnects For Pcb Electronics, John Crowder

All Theses

With the increasing prevalence of electronic equipment worldwide, there is also a decrease in the size of the components on their printed circuit boards (PCBs), leading to an increase in the density of these components. A significant amount of failure in electronic equipment is vibration fatigue of solder joints and their attachments. However, the complexity of these PCBs and their components has made finite element modeling (FEM) more complex, adding considerable time to create and analyze a model.

This paper aims to provide a literature review for the vibration fatigue of leaded solder components, create a test setup, and validate …

Machine Learning-Based Data And Model Driven Bayesian Uncertanity Quantification Of Inverse Problems For Suspended Non-Structural System, Zhiyuan Qin

All Dissertations

Inverse problems involve extracting the internal structure of a physical system from noisy measurement data. In many fields, the Bayesian inference is used to address the ill-conditioned nature of the inverse problem by incorporating prior information through an initial distribution. In the nonparametric Bayesian framework, surrogate models such as Gaussian Processes or Deep Neural Networks are used as flexible and effective probabilistic modeling tools to overcome the high-dimensional curse and reduce computational costs. In practical systems and computer models, uncertainties can be addressed through parameter calibration, sensitivity analysis, and uncertainty quantification, leading to improved reliability and robustness of decision and …

Fatigue Performance Of Flexural Retrofits For Precast Slab Bridges, Ian Stewart

All Theses

This thesis discusses flexural and cyclic load testing of two potential retrofits for pre-cast slab bridges. These slabs came from South Carolina Department of Transportation (SCDOT) decommissioned bridges as a part of an ongoing project with SCDOT. The first is a Carbon Fiber Reinforced Plate (CFRP) retrofit where four CFRP plates were adhesively bonded to the bottom of a slab. The second is a steel plate that was mechanically attached to the bottom of a slab using bolted connections. The bolts were cast into grouted holes in the slab. To better understand the failure mode of these retrofits and their …

Assessing Key Factors Influencing Fire-Induced Spalling Of Concrete Using Explainable Artificial Intelligence (Xai), Mohammad Khaled Gazi Albashiti

All Theses

This thesis adopts eXplainable Artificial Intelligence (XAI) to identify the key factors influencing the fire-induced spalling of concrete and to extract new insights into the fire-induced spalling phenomenon. In this pursuit, an XAI model was developed, validated, and then augmented with two explainability measures, namely, Shapley Additive exPlanations (SHAP) and Local Interpretable Model-Agnostic Explanations (LIME). The proposed XAI model not only can predict the fire-induced spalling with high accuracy (i.e., >92 %) but can also articulate the reasoning behind its predictions (as in, the proposed model can specify the rationale for each prediction instance); thus, providing us with valuable insights …

An Experimental And Numerical Investigation Of The In-Plane Shear Behavior Of Cantilever Cross-Laminated Timber Diaphragms, Bibek Bhardwaj

All Dissertations

This research focuses on investigating the behavior of Cross Laminated Timber (CLT) diaphragms under in-plane shear loads through an experimental, analytical, and numerical approach. Full-scale destructive tests were conducted on cantilever CLT diaphragms to measure their response to cyclic loading. The results showed that the ultimate capacity of the diaphragms was primarily influenced by the fasteners used and exceeded the LRFD capacity. The primary energy dissipation mechanism was through the slip of diaphragm components and rotation of CLT panels due to fastener deformations. The strain data revealed that the diaphragms exhibited deep-beam-like behavior, with resistance to tensile and compressive forces …

Flexural Testing Of Precast Reinforced Concrete Bridge Slabs, Evaluation Of Deterioration And Strengthening Applications, Alyssa Leaman

All Theses

This thesis investigates the strength of flat precast concrete slabs that were taken from decommissioned South Carolina bridges. The specimens tested spanned 14 ft (4.3 m) or 15 ft (4.6 m), were 5 ft (1.5 m) or 5.5 ft (1.7 m) wide, and 8.25 in (210 mm) thick. In South Carolina, there are approximately 3000 similar bridges that use these slab members. Testing was conducted to determine the flexural capacity of “typical” slabs and the residual strength of slabs having visible deterioration of both the rebar and the concrete. For the slabs that were load rated below the new standards, …

Performance Based Design And Machine Learning In Structural Fire Engineering: A Case For Masonry, Deanna Craig

All Theses

The volatile and extreme nature of fire makes structural fire engineering unique in that the load actions dictating design are intense but not geographically or seasonally bound. Simply, fire can break out anywhere, at any time, and for any number of reasons. Despite the apparent need, fire design of structures still relies on expensive fire tests, complex finite element simulations, and outdated procedures with little room for innovation. This thesis will make a case for adopting the principles of performance-based design and machine learning in structural fire engineering to simplify the process and promote the consideration of fire in all …

Flexural Bond Strength Of Masonry Assemblies With Lightweight Grout, Benjamin L. Hiner

All Theses

Lightweight grout has many potential benefits in masonry construction, including minimizing mass, improving thermal performance, and potentially reducing shrinkage cracking via internal curing. However, insufficient testing of masonry assemblies with lightweight grout has been conducted to suggest appropriate design modification factors akin to the lambda factor in ACI 318-19. The objective of this paper is to study the tensile bond behavior of masonry assemblies grouted with lightweight grout and to suggest appropriate equations for predicting design capacity. A moment couple test is designed specifically for grouted masonry assemblies and has additional capacity compared to the traditional ASTM 1072 bond wrench …

Tessellated Structural-Architectural Systems: Experimental Testing And Interdisciplinary Student Projects, Grace F. Crocker

All Dissertations

This dissertation discusses a new structural system called a Tessellated Structural-Architectural (TeSA) system. These TeSA systems utilize architecturally appealing tessellations in load-bearing structures comprised of interlocking tiles in a pattern. This dissertation focuses on the design, construction, and structural behavior of these TeSA systems, as well as their value as an interdisciplinary learning tool.

This dissertation has 4 research objectives: 1) Demonstrate the fabrication and construction of a precast reinforced concrete (RC) TeSA shear wall system; 2) Measure the structural performance of the RC TeSA shear wall system; 3) Compare simplified shear and flexural analysis methods for RC TeSA shear …

The Evacuation Simulation Of Wheelchair Users In A Building Fire: An Initial Dynamic Characterization Of Structural Egress Components, Haley Hostetter

All Theses

People with disabilities are one of the most vulnerable groups involved in building fires. According to the U.S. Fire Administration, in the United States alone, an estimated 700 home fires involve people with physical disabilities each year while over 1700 involve those with mental health disorders. Despite this, the current body of literature shows few studies focused on the evacuation of disabled people. This is a direct result of past and present social injustice on people with disabilities and has resulted in high injury and death rates during fires. To combat this, enrich the literature, and improve their experiences in …

Rapidly Deployable Structures For Disaster Relief And Military Use, Jayson Leonard

All Theses

Rapidly deployable structures currently play a vital role in the recovery aspect of disaster-stricken areas and the safety of military personnel in hostile zones. More recently there has also been a need for the structures to deal with unforeseen disruptions caused by the COVID pandemic, such as COVID testing centers or backyard pop-up offices. These structures could be used in different environments and serve many other purposes. Along with the structural performance of these shelters, they need to integrate into systems set in place effortlessly. For that reason, four key factors were taken into consideration, namely (1) deployability (how difficult …

Crack Control And Bond Performance Of Alternative Coated Reinforcements In Concrete, Sachin Sreedhara

All Dissertations

Concrete cracking in structures is a ubiquitous problem which can lead to the deterioration of the structure. Other than affecting the strength aspect of a structure, cracking impacts the serviceability criteria as well. Although cracking phenomenon in any structure is highly inevitable, it has to be minimized in order to maintain a structure’s life effectively. Cracking in reinforced concrete structures is related to the bond strength developed between the bar and the concrete. It also depends on an ability of the bar to resist the stresses due to shrinkage to minimize the crack. Another important aspect is the resistance offered …

Seismic Performance Assessment Of Building Contents: Monetary Losses And Injuries, Sereen Majdalaweyh

All Dissertations

Building contents include all the components that are not attached to the building which the owners place after the construction phase, such as furniture, electrical equipment, glassware, and other personal items. Loss and damage assessment of building contents proved to be challenging in performance-based earthquake engineering frameworks because of the data sparsity. Damages to building contents during an earthquake not only cause monetary losses; tumbling and over-toppling of heavy building contents could result in injuries and even deaths of occupants. While major advancements have been made in performance-based earthquake engineering; however, the focus is mainly on damages and collapse risk …

Development And Promotion Of Mass Timber Noise Barrier For Highways, Harsh Bothra

All Theses

Highways are some of the biggest causes of noise pollution in the United States of America. To deal with the traffic noise coming from these highways, noise barriers have been erected across major highways. The goal is to reduce as much noise as possible through a sustainable solution. Unfortunately, the use of steel and concrete, commonly used materials, have undesired environmental impacts. A suggested sustainable alternative material would be mass timber. Mass timber products such as cross-laminated timber (CLT) and mass plywood panels (MPP) has attracted the attention of the construction industry in the U.S, as they are sustainable, light, …

Development Of Lambda Factors For Masonry Design With Lightweight Grout, Rumi Shrestha

All Theses

Reduction in structural mass, improvement in thermal performance, and reduction in shrinkage cracking through internal curing are some of the reasons that lightweight (LW) aggregates have been used in structures and pavements for decades. However, lightweight grout is still not permitted for use in reinforced masonry construction by the TMS 402/602-16 code. In order to realize the benefits of lightweight grout in U.S. reinforced masonry construction, a codified procedure for its use is required which must be informed by experimental testing.

This research is a pilot project directed to characterize the performance of LW grout in comparison to normal weight …