Civil Engineering Commons^™

Non-Newtonian Model Development For Post-Wildfire Flood Risk Management, Ian Eli Floyd

LSU Doctoral Dissertations

Wildfire effected regions of the western U.S. frequently produce non-Newtonian floods (or floods that have a non-linear relationship between stress and deformation) in response to moderate to severe precipitation events. This research presents the development, evaluation, and demonstration of a post-wildfire hydrodynamic one-dimensional and two-dimensional diffusive wave and shallow-water numerical modeling approach that can be used to predict post-wildfire downstream runout of debris flows and floodplain inundation conditions. While researchers have developed a variety of Non-Newtonian approaches to simulate debris flows and mudflows, there has been very limited application to post-wildfire flooding. This can make it difficult to understand the …

Analysis Of Tensegrity Structures Using Abaqus, Kayla M. Allen

Honors College Theses

This project involves modeling and analysis of a tensegrity structure using the finite element approach utilizing the Abaqus software package. A tensegrity structure is a special type of assembly consisting of a series of straight solid members, arranged in various geometrical configurations in three-dimensional space and held together by series of cables. The developed finite element models for several tensegrity structures are included in this thesis report to better describe the project.

Evaluation Of Compatibility Between Asphalt Binders And Mineral Aggregates, Tandra Bagchi

Student Theses and Dissertations

One of the major problems of asphalt concrete pavements faced by most state Departments of Transportations (DOTs) and other highway agencies is moisture damage. Poor compatibility between asphalt binders and aggregates is the main reason behind such kind of distresses. This study aims to conduct compatibility analyses of selected asphalt binders and aggregates used in Arkansas. Asphalt binders used in this study include two Performance Grade (PG) binders (PG 64-22) from two different sources along with their modified counterparts. Additionally, four different types of aggregates are being evaluated in the laboratory. The Sessile Drop method has been followed to determine …

Temperature Gradient Effects On Behavior And Design Of Prestressed Concrete Girder Bridges, Ahmed Saad Elsayed Mohamed Elshoura

LSU Doctoral Dissertations

Temperature variation is an inevitable environmental loading type that affects bridges. Considering temperature effects during structural design is deemed essential for short, medium, and long span bridges. Temperature loading can be categorized into three components; uniform temperature, vertical temperature gradient, and transverse temperature gradient. Temperature variation causes additional movements, stresses, and internal forces that should be considered in the design of bridges. In this study, the temperature effects of vertical and transverse temperature gradients are investigated for continuous prestressed concrete bridges.

Thermal restraint moments induced by vertical temperature gradients on prestrssed concrete bridges are investigated by performing three-dimensional (3D) finite …

Feasibility Of Using A High-Power Electromagnetic Energy Harvester To Power Structural Health Monitoring Sensors And Systems In Transportation Infrastructures, Mohsen Amjadian, Anil K. Agrawal, Hani Nassif

Civil Engineering Faculty Publications

This paper investigates the feasibility of an electromagnetism energy harvester (EMEH) for scavenging electric energy from transportation infrastructures and powering of conventional sensors used for their structural health monitoring. The proposed EMEH consists of two stationary layers of three cuboidal permanent magnets (PMs), a rectangular thick aircore copper coil (COIL) attached to the free end of a flexible cantilever beam whose fixed end is firmly attached to the highway bridge oscillating in the vertical motion due to passing traffic. The proposed EMEH utilizes the concept of creating an alternating array of permanent magnets to achieve strong and focused magnetic field …

Longitudinal Trajectory Tracking Analysis For Autonomous Electric Vehicles Based On Pid Control, Hossein Amiri

USF Tampa Graduate Theses and Dissertations

The implementation of autonomous vehicles has huge potential for revolutionizing transportation as we currently know it. All use cases of autonomous vehicles require the vehicle to travel on a pre-specified path. Accurate tracking of this defined trajectory is a crucial aspect of the implementation of autonomous vehicles; a controller system is required to translate this pre- defined trajectory in the form of the throttle, brake, and steering inputs. This project covers the application of a Proportional-Integral-Derivative (PID) controller to achieve longitudinal trajectory tracking of autonomous electric vehicles with stability and accuracy in the CARLA autonomous driving simulation platform. The implemented …

Prediction Of The Effects Of Turbulence On Vehicle Hydroplaning Using A Numerical Model, Thathsarani Dilini Herath Herath Mudiyanselage

USF Tampa Graduate Theses and Dissertations

Pneumatic hydroplaning has been identified as one of the major causes of wet weathertraffic accidents. Therefore, knowledge of potential hydroplaning speeds is crucial in designing roadways to reduce crash risks. It has been shown that the tire inflation pressure is the predominant factor affecting the hydroplaning speed while factors such as the water film thickness also contribute heavily to this phenomenon. Extensive research has been directed at the development of accurate models to predict the effects of vehicle characteristics, pavement conditions and water film thickness on hydroplaning. Current literature does not indicate any studies directed at understanding the effects of …

Feasibility Of Epoxy Bond Enhancement On High-Strength Concrete, Amanda A. Lewis

USF Tampa Graduate Theses and Dissertations

While fiber-reinforced polymer materials have many applications in various industries,when used structurally, many cases, such as flexural and shear strengthening, are considered bond critical. Interfacial bond quality between a fiber-reinforced polymer system and the substrate is dependent on two mechanisms: chemical bonding and mechanical interlock, with mechanical interlock having the greater effect on bond quality. Mechanical interlock describes the type of bond that occurs as a result of surface roughness and substrate porosity and can be significantly affected by surface preparation methods and surface moisture. This study aims to explore the possibility of enhancing bond quality between carbon-fiberreinforced polymers and …

Soil Improvement By Electro-Osmotic Consolidation: Laboratory Testing, Yenni Mariana Ramírez-Mazo, Juan Pablo Osorio, Sergio C. Agudelo-Flórez

Conference papers

Electro-osmotic consolidation is a ground improvement technique that has been successfully implemented on the field and at laboratory scale since the 30s. However, its application has been done primarily through empirical procedures and experience. The determinant variables in the effectiveness and efficiency of the improvement are numerous and require further studies. This paper presents the evaluation of the improvement process of an inorganic low plasticity clay subjected to a 150 V/m voltage during 5780 minutes. The special analysis of the strains showed differential settlements, as well as cracking at the surface and with depth. The consolidations curves obtained follow the …

A Non-Destructive Electromagnetic Sensing Technique To Determine Chloride Level In Maritime Concrete, Goran Omer Dr, Patryk Kot Dr, William Atherton Dr, Magomed Muradov Dr, Michaela Gkantou Dr, Andy Shaw Prof, Michael Riley Prof, Khalid Hashim Dr., Ahmed Al-Shamma’A

Karbala International Journal of Modern Science

Deterioration of concrete due to the corrosion of reinforcement is a serious durability problem faced by the construction industry. This study aims to develop a non-destructive and real-time technique to monitor the chloride level at an early stage to prevent the development of the reinforcement’s corrosion using electromagnetic spectroscopy. The experimental work was performed on 5 concrete specimens with different chloride levels at three different concrete depths (18, 40, and 70mm) using the sensor system (2-12GHz frequency range) and a chlorometer. The LM algorithm was selected to develop a prediction model for the detection of chloride ions. The results demonstrated …

The Prospect Of Microwave Heating: Towards A Faster And Deeper Crack Healing In Asphalt Pavement, Shi Xu, Xueyan Liu, Amir Tabakovic, Erik Schlangen

Articles

Microwave heating has been shown to be an effective method of heating asphalt concrete and in turn healing the damage. As such, microwave heating holds great potential in rapid (1–3 min) and effective damage healing, resulting in improvement in the service life, safety, and sustainability of asphalt pavement. This study focused on the microwave healing effect on porous asphalt concrete. Steel wool fibres were incorporated into porous asphalt to improve the microwave heating efficiency, and the optimum microwave heating time was determined. Afterwards, the microwave healing efficiency was evaluated using a semi–circular bending and healing programme. The results show that …

The Effect Of Cement And Blast Furnace Slag Characteristics On Expansion Of Heat-Cured Mortar Specimens, Jair G. Burgos

USF Tampa Graduate Theses and Dissertations

Delayed ettringite formation (DEF) is a durability issue that typically occurs in concrete exposed to high temperatures at an early age such as precast elements and massive concrete structural elements. There are many advantages to precast concrete such as its quality control, better safety control, and reusable forms, which make them cheaper than casting on site [1]. Heat curing of precast concrete is conducted to obtain high early-strength. However, in doing so, durability issues can arise in the form of internal sulfate attack also known as DEF, if the internal temperature of concrete exceeds 70°C. Past this threshold, ettringite decomposes …

Machine Learning Methods To Map Stabilizer Effectiveness Based On Common Soil Properties, Amit Gajurel, Bhaskar Chittoori, Partha Sarathi Mukherjee, Mojtaba Sadegh

Civil Engineering Faculty Publications and Presentations

Most chemical stabilization guidelines for subgrade/base use unconfined compressive strength (UCS) of treated soils as the primary acceptance criteria for selecting optimum stabilizer in laboratory testing. Establishing optimal additive content to augment UCS involves a resource-intensive trial-and-error procedure. Also, samples collected from discrete locations for laboratory trials may not be representative of the overall site. This study aims to minimize the number of laboratory trials and help strategize sampling locations by developing spatial maps of UCS at different treatment levels for lime and cement. These spatial maps were developed using machine-learning techniques, and using a database compiled from various reported …

Accelerated Controller Tuning For Wind Turbines Under Multiple Hazards, Aly Mousaad Aly, Milad Rezaee

Faculty Publications

During their lifecycle, wind turbines can be subjected to multiple hazard loads, such as high-intensity wind, earthquake, wave, and mechanical unbalance. Excessive vibrations, due to these loads, can have detrimental effects on energy production, structural lifecycle, and the initial cost of wind turbines. Vibration control by various means, such as passive, active, and semi-active control systems provide crucial solutions to these issues. We developed a novel control theory that enables semi-active controller tuning under the complex structural behavior and inherent system nonlinearity. The proposed theory enables the evaluation of semi-active controllers’ performance of multi-degrees-of-freedom systems, without the need for time-consuming …

A Comparison Of Porphyrin Photosensitizers In Photodynamic Inactivation Of Rna And Dna Bacteriophages, Joe Heffron, Matthew Bork, Brooke K. Mayer, Troy Skwor

Civil and Environmental Engineering Faculty Research and Publications

Effective broad-spectrum antiviral treatments are in dire need as disinfectants and therapeutic alternatives. One such method of disinfection is photodynamic inactivation, which involves the production of reactive oxygen species from dissolved oxygen in response to light-stimulated photosensitizers. This study evaluated the efficacy of functionalized porphyrin compounds for photodynamic inactivation of bacteriophages as human virus surrogates. A blue-light light emitting diode (LED) lamp was used to activate porphyrin compounds in aqueous solution (phosphate buffer). The DNA bacteriophages ΦX174 and P22 were more resistant to porphyrin TMPyP photodynamic inactivation than RNA bacteriophage fr, with increasing rates of inactivation in the order: ΦX174 …

A Decision-Support System For The Deployment Tasking Process Of U.S. Air Force Civil Engineer Officers, Kenneth A. Neal

Theses and Dissertations

The Armed Forces frequently deploy their personnel to expeditionary locations around the world. For example, the Air Force tasks its personnel to deploy based on a six-month rotational cycle. In the current tasking process, the deployment makes its way down from combatant commanders to squadron commanders through the chain of command. The commander then has a few days to select an individual from their unit to fill the tasking. The commander may consider an individuals’ dwell time, home-station position, and upcoming significant life events; however, because commanders have little time and information, minimum requirements selection criteria often become the driving …

Investigating Manufacturer Selection Decisions For Built Infrastructure Assets Using A Technical Performance Metric, Sarah L. Brown

Theses and Dissertations

Facility and built infrastructure asset management are necessary functions of any organization that utilizes buildings to operate their businesses. However, most organizations require facility managers to ensure the successful operation of their assets without providing sufficient resources to accomplish this task. Therefore, in resource-scarce environments, facility managers require data-driven solutions to manage their assets and make the best decisions. Facility managers need novel solutions to help make asset life-cycle decisions. This research provides such a solution. Capitalizing on available data, a technical performance metric is created, allowing facility managers to calculate their assets' operational performance. This performance metric provides a …

The Effects Of Waste Marble Powder On Sustainable Concrete, Jeremy S. Tennesen

Construction Management

Sustainability has been growing consistently more popular in construction, with projects introducing innovative ideas to build greener every year. One material that has not experienced many innovations since emerging in building use is concrete. The reason behind this could be the chemical process of curing concrete being unique compared to most materials. While concrete can be broken down into some of its original components, water, cement, and admixtures used are not retainable. This makes it difficult to recycle the material, and the aggregates recovered from recycling also experience a loss in strength. With admixtures being involved in most concrete mixes …

Bs News March/April

Building Services Engineering

No abstract provided.

Initial Assessment Of Liquefied Scrap Tire Concrete, Abdulkareem Kuaryouti, Christopher D. Eamon

Civil and Environmental Engineering Faculty Research Publications

A new approach to incorporate scrap tire material into concrete was investigated, where two reclaimed waste tire components, carbon black and fuel oil, were used to replace a portion of water. The effect of “liquid tire” content to water ratios from 5-40% on an otherwise typical concrete mix were assessed, where compressive and flexural strength, flexural toughness, modulus of elasticity, and several fresh concrete properties were determined. Results were compared to typically expected results of traditional shredded tire mixes with equivalent tire content. It was found that the liquid tire mixes experienced significantly less losses of compressive strength and workability …