Civil and Environmental Engineering Commons^™

Assessment Of Engineering Performance And Environmental Impacts Of High Reclaimed Asphalt Pavement (Rap) Asphalt Mixtures In Flexible Pavements, Ibrahim A.I.E. Elnaml

LSU Doctoral Dissertations

Due to the critical role of asphalt pavements in national infrastructure development, there is a pressing need to investigate more sustainable materials and approaches. The use of natural aggregates and asphalt binders in asphalt pavement presents sustainability challenges due to the depletion of finite resources. Recycling Asphalt Pavement (RAP) offers a promising sustainable solution by substituting virgin aggregates and asphalt binders with recycled ones. However, increasing RAP contents in asphalt mixtures (>25%) can lead to premature cracking, insufficient durability, and limited longevity due to the presence of aged RAP-asphalt binder. To address these concerns, the application of novel recycling …

Investigating Gulf Coast Aquifer System: Stratigraphy Reconstruction, Inverse Modeling, And Groundwater Stress Assessment, Shuo Yang

LSU Doctoral Dissertations

The Mississippi Embayment aquifer system (MEAS) and the Coastal Lowlands aquifer system (CLAS) provide substantial groundwater resources for human activities in the U.S. Gulf Coastal Plain. However, the overexploitation has led to groundwater depletion in the MEAS and the CLAS, threatening sustainable groundwater use. Such concern highlights the crucial need for an advanced understanding of stratigraphy and groundwater in these aquifer systems, which is essential for effective regional groundwater management. This dissertation presents a comprehensive investigation of MEAS and CLAS in the Louisiana and southwestern Mississippi region, encompassing three fundamental dimensions: stratigraphy reconstruction, groundwater modeling, and groundwater stress assessments. A …

Understanding And Modeling Drivers’ En-Route Diversion Behavior During Congestion, Mohammad Shapouri

LSU Doctoral Dissertations

In the field of transportation, traffic assignment models primarily have been used to forecast driver route preferences, translating their choices into traffic flow patterns across networks. These models are grounded in distinct behavioral theories and strive to explain how drivers navigate routes based on network features and personal tendencies. Using an aggregation approach, conventional traffic assignment models distribute demand among paths, considering utility and attractiveness. Despite their prevalent use in transportation planning and operations, the fundamental behavioral assumptions of these models have rarely been thoroughly explored. This gap is further compounded by their limited consideration of real-time adjustments and choices …

Understanding And Modeling Drivers’ En-Route Diversion Behavior During Congestion, Mohammad Shapouri

LSU Doctoral Dissertations

In the field of transportation, traffic assignment models primarily have been used to forecast driver route preferences, translating their choices into traffic flow patterns across networks. These models are grounded in distinct behavioral theories and strive to explain how drivers navigate routes based on network features and personal tendencies. Using an aggregation approach, conventional traffic assignment models distribute demand among paths, considering utility and attractiveness. Despite their prevalent use in transportation planning and operations, the fundamental behavioral assumptions of these models have rarely been thoroughly explored. This gap is further compounded by their limited consideration of real-time adjustments and choices …

Residential Building Flood Risk Assessment And The Benefits Of Home Elevation, Ayat Al Assi

LSU Doctoral Dissertations

Evaluating flood risk is an essential component of understanding and increasing community resilience. A robust approach for quantifying flood risk in terms of average annual loss (AAL) in dollars is needed to provide valuable information for stakeholder decision-making inside and outside the special flood hazard area (SFHA, which corresponds to the 100-year floodplain). To further inform flood mitigation strategies, quantifying flood risk reduction with home elevation above an initial first-floor height (FFH₀) and the cost effectiveness of federal mitigation assistance for elevation are important steps to enhance awareness of the effect of elevation in reducing flood risk. …

Physics-Based Crystal Plasticity Model For Predicting Microstructure Evolution And Dislocation Densities, Juyoung Jeong

LSU Doctoral Dissertations

This work presents three different studies investigating plastic deformation mechanisms in metals and alloys using crystal plasticity finite element (CPFE) modeling. The first study presents a new nonlocal crystal plasticity model for face-centered cubic single crystals under heterogeneous inelastic deformation. The model incorporates generalized constitutive relations that incorporate the thermally activated and drag mechanisms to cover different kinetics of viscoplastic flow in metals and describes the plastic flow and yielding of single-crystals using dislocation densities. The model is compared to micropillar compression experiments for copper single crystals and clarifies the complex microstructural evolution of dislocation densities in metals. The second …

Numerical Investigation Of Heat Generation And Accumulation Contributing To Elevated Temperature In Msw Landfills, Alborz Fathinezhad

LSU Doctoral Dissertations

Landfills are complex geostructures which contains organic and inorganic municipal, and in some cases industrial, wastes and are expected to remain operational for long times. Due to the complex nature of physical, chemical, biological, and thermal reactions that carry on within the depths of a landfill, unexpected incidents such as elevated temperatures could become inevitable. While uncommon to happen, elevated temperatures cause health and environmental issues such as odors, rapid settlements, slope instabilities. In addition, elevated temperatures can negatively impact engineered components in composite bottom liners, cover systems, leachate collection, and gas extraction and recovery systems.

Air intrusion into municipal …

Toward A Safer Transportation System For Senior Road Users, Saba Doulabi

LSU Doctoral Dissertations

Senior pedestrians and drivers (65 years and older) are among the most vulnerable road users. As the population of seniors rise, concerns regarding older adults' traffic safety are growing. The advantages of using autonomous vehicles, innovative vehicle technologies, and active transportation are becoming more widely recognized to improve seniors' mobility and safety. This behooves researchers to further investigate senior road users’ safety challenges and countermeasures. This study contributes to the literature by achieving two main goals. First, to explore contributing factors affecting the safety of older pedestrians and drivers in the current transportation system. Second, to examine seniors’ perceptions, preferences, …

Incorporating Geopolymer Binders To Fully Utilize Recycled Concrete Aggregates, Matthew Upshaw

LSU Doctoral Dissertations

This study aims to develop a geopolymer concrete binder that will yield desirable strength and durability characteristics when applied to recycled aggregate concrete. In order to achieve this, a geopolymer binder consisting of a metakaolin-silica fume aluminosilicate source material blend activated by potassium-based alkaline solutions is developed and used in place of ordinary Portland cement (OPC) with four different levels of recycled aggregate replacement ratios. The properties of these concretes were analyzed and compared with the properties of OPC concretes produced with the same replacement ratio levels. The results showed that the geopolymer recycled aggregate concrete (GRAC) achieved greater than …

Numerical Modeling Of Bulk Sediment Deposition And Scour In The Lower Mississippie River Physical Model, Ronald Joseph Rodi

LSU Doctoral Dissertations

Land loss restoration along the southeast Louisiana coast relies on the replenishment of sand from the sediment of the Mississippi River. To further the understanding of sediment transport and hydraulic characteristics of the lowermost segment of the river, the Louisiana Coastal Protection and Restoration Authority (CPRA) funded construction of the Lower Mississippi River Physical Model (LMRPM). This distorted-scale, movable bed model encompasses the lowermost 193-mile reach of the river, including from Donaldsonville, Louisiana to the Gulf of Mexico the Bonnet Carre Spillway and planned river sediment diversions.

Designed to replicate the prototypical river hydraulics and bulk bedload (sand) transport, scaled …

A New Generation Of Open-Graded Friction Course For Enhanced Durability And Functionality, Hossam Abohamer

LSU Doctoral Dissertations

This study aims at (1) enhancing Open Graded Friction Course (OGFC) mixes durability using additives and other by-products; (2) investigating the impacts of selected factors on OGFC pavements seepage characteristics; (3) developing a quantitative tool to model the deterioration in OGFC pavements functional performance; and (4) developing new guidelines of Air Void (AV) content for OGFC for optimum functionality and durability. For the durability objective, eight mixes were prepared with a PG 76-22 binder and two sources of aggregate (i.e., # 78 limestone and # 67 sandstone). Three Warm Mix Additives (WMA), one by-product (i.e., crumb rubber [CR]), and two …

Investigation Of Groundwater Depletion And Leveel Underseepage With Unstructured-Grid Modeling Approach, Ye-Hong Chen

LSU Doctoral Dissertations

Unstructured grid is a tessellation of geometric shapes in irregular patterns that provides flexibility in grid design for groundwater modeling. However, groundwater modeling is mostly developed with uniform grid tessellation and layer, which could simplify model structure or cause expensive computational costs in high-resolution simulations. Unstructured grid incorporates non-uniform horizontal and non-uniform vertical discretizations providing the capability to replicate complex hydrostratigraphy, capture geologic features that are crucial for groundwater flow simulation, and reduce computational costs while maintaining a high resolution for areas of interest. This study contains three parts to investigate unstructured-grid approach on constructing high-fidelity groundwater models, comparisons with …

Use Of Halide Radicals In Water Treatment, Madhusudan Kamat

LSU Doctoral Dissertations

The increasing population and a reduction in freshwater resources has made the reuse of water imperative [1-3]. Advanced oxidation processes (AOPs) enable the safe reuse of wastewater through the removal of persistent pollutants. The highly reactive nature of reactive species, like hydroxyl radicals is limited by their reactivity with ubiquitous compounds like dissolved organic matter (DOM)[4, 5]. The use of halide radicals can help improve the efficiency of UV-based AOPs.

This thesis investigates the mechanism of halide radicals in three different systems: a) the use of iodine radicals in functionalized fullerenes b) the use of UV/chlorine as an advanced oxidation …

Numerical Investigation Of The Impact Of Distortion On The Hydrodynamics In The Lower Mississippi River Physical Model (Lmrpm), Ali Heidarizhaleh

LSU Doctoral Dissertations

The Lower Mississippi River Physical Model (LMRPM) is a distorted-scale, 1:6000 horizontal and 1:400 vertical, movable-bed model that is being used to complement ongoing numerical and field studies directed at studying how non-cohesive sediment transport will be impacted by future changes in relative sea level rise and river discharges, as well various management strategies, such as river sediment diversions, in the lower ~190 miles of the Mississippi River The LMRPM was designed using Froude number (Fr) similarity between the prototype and the model, while the flow Reynolds number is relaxed, but determined to be high enough to ensure rough turbulent …

An Improved Earned Value Management Method Integrating Quality And Safety, Brian Briggs

LSU Doctoral Dissertations

The construction industry invests significant time and money to improve quality and safety while reducing cost and schedule impacts. The industry has a sincere desire to improve construction project management methods to improve efficiency. Historically, quality and safety underperformances result from undermanaged quality control and safety activities. The cost and schedule impacts associated with poor quality work have always had an impact on construction operations. The unprecedented challenges and uncertainties of COVID-19 highlighted the need to improve the Earned Value Management (EVM) method within construction to reflect these quality and safety activities. The central goal of this dissertation is to …

Impact Of Personality Traits And Team Criteria On Construction Team Performance, Arlys Silva Payne

LSU Doctoral Dissertations

This dissertation investigated how personality traits and team criteria influence team performance in real construction projects. Though personality influence on team performance has been significantly investigated in other business sectors, the literature revealed that the construction industry lacks investigations regarding personality influencing team performance. The existing literature revealed that the Big Five Factors (BFF) was the most popular assessment tool for personality. Thus, this dissertation adopted the 50-Item Personality questionnaire developed by Goldberg, which consited of extraversion, aggreeableness, conscientiousness, neuroticism, and openness to experience. The literature also revealed several common team criteria to evaluate team performance: team member satisfaction, shared …

Single-Family Residential Flood Loss Reduction Through Freeboard, Ehab Said Gnan

LSU Doctoral Dissertations

The lack of flood loss estimation methods conducted on a micro-scale level that consider the full loss‐exceedance probabilities curve poses a significant problem in flood risk assessment. Also, the lack of robust benefit-cost analysis (BCA) that quantifies benefits at the micro-scale level leads to sub-optimal results, and therefore sub-optimal decisions when determining the optimal freeboard. Further, flood loss assessments focus on owner-occupied housing and neglect rental housing. These loss assessment deficiencies underscore the need for a robust assessment that quantifies the life-cycle benefits for all stakeholders and provides actionable information to enable informed decisions.

This research presents a comprehensive methodology …

Vertical Feature Delineation For Flood Hazard Assessments At The Coastal Land Margin, Shu Gao

LSU Doctoral Dissertations

Coastal and riverine flooding constitutes a major environmental hazard that affect millions of people residing along the world’s coastline. Improved understanding of the driving mechanisms that can cause flooding within coastal watersheds requires advanced hydrologic and coastal storm surge simulation. Such advanced simulation is dependent upon an accurate digital elevation model (DEM) for the optimal topographical representation of the true domain in the discretized model grid (mesh). However, it is not possible to afford mesh resolution as fine as contemporary DEMs, resolved at sub-10 meters, due to the impractical computational expense. Therefore, significant elevation barriers such as roadbeds, levees, railroads, …

Studying Complex Aquifer Systems From Large-Scale Stratigraphy Development To Local Aquifer Storage And Recovery, Hamid Vahdat Aboueshagh

LSU Doctoral Dissertations

Hydrostratigraphy model is an essential component of building valid groundwater models. Many challenges are associated with constructing hydrostratigraphy models which include geological complexities such as faults, domes, and angular unconformities. Developing a method with an emphasis on capturing big data to thoroughly inform large-scale models is one of the challenges addressed in the first part of this study. The method is predicated upon discretization of the study domain into tiles based on the geological dip direction and faults. The application of the method in the state of Louisiana with the utilization of more than 114000 well logs demonstrates promising results …

Simulation Of Compound Flood Events In Low-Gradient Coastal Watershed, Felix Luis Santiago-Collazo

LSU Doctoral Dissertations

Low-gradient coastal watersheds are susceptible to flooding caused by various flows such as rainfall, tides, and storm surge. Compound flooding occurs when at least two of these mechanisms happen simultaneously or in close succession. Different inundation models, observed data, and/or a combination of these are coupled through varying techniques involving one-way, loosely, tightly, or fully coupled approaches to assess compound flooding. This study presents a one-dimensional (1-D), fully coupled compound inundation model based on the Shallow Water equations. This model approach simultaneously simulates the free water surface variations in the ocean domain (i.e., tide and storm surge modeling), rainfall-runoff in …

Atomistic Thermo-Mechanical Description Of The Deformation Behavior, Scaling Laws, And Constitutive Modeling Of Nanoporous Gold, Mohammed Hassan Yousef Saffarini

LSU Doctoral Dissertations

Metallic foams, or nanoporous (NP) metals as it is widely referred to in literature, with ligament sizes up to a few tens of nm show exceptional mechanical properties such as high strength and stiffness per weight ratio under different loading scenarios due to their high surface area to solid volume ratio. Therefore, they can be utilized in a wide range of applications making them of great interest to researchers. While their elasticity and yield strength have been the subject of several studies, very limited attention was given to the effect of size, strain rate, and temperature on the material plastic …

Fatigue Monitoring Through Wearable Sensors For Construction Workers, Srikanth Sagar Bangaru

LSU Doctoral Dissertations

About 40% of the US construction workforce experiences high-level fatigue, which leads to poor judgment, increased risk of injuries, a decrease in productivity, and a lower quality of work. Excessive fatigue from working in unpleasant working conditions, long working hours, or heavy workloads can aggravate fatigue's adverse effects, leading to work-related musculoskeletal disorders (WMSDs) and productivity loss. Therefore, it is essential to monitor fatigue to reduce the adverse effects and preventing long-term health problems. However, since fatigue demonstrates itself in several complex processes, there is no single standard measurement method for fatigue detection. This research aims to develop a system …

Error Prevention In Sensors And Sensor Systems, Pedro J. Chacon Dominguez

LSU Doctoral Dissertations

Achievements in all fields of engineering and fabrication methods have led towards optimization and integration of multiple sensing devices into a concise system. These advances have caused significant innovation in various commercial, industrial, and research efforts. Integrations of subsystems have important applications for sensor systems in particular. The need for reporting and real time awareness of a device’s condition and surroundings have led to sensor systems being implemented in a wide variety of fields. From environmental sensors for agriculture, to object characterization and biomedical sensing, the application for sensor systems has impacted all modern facets of innovation. With these innovations, …

Modeling Hydraulic Fracturing Initiation And Propagation In Porous Rock Formationsl, Chang Huang

LSU Doctoral Dissertations

Hydraulic fracturing has long been introduced to the oil and gas industry since the early nineteenth century for both reservoir characterization and reservoir stimulation. Despite the progress made in the last two decades, many challenges still have not been tackled regarding not only the propagation problem but also the initiation problem due to its complexity. The dissertation is divided into two stages, i.e., before and after fracture initiation. The first stage of the research aimed at improving the accuracy in solving the poro-mechanical response of wellbore during fluid injection before a tensile fracture occurs, which is crucial to determine the …

Development Of Cracking Resistance Prediction Model Of Long-Term Aged Asphalt Mixtures, Peyman Barghabany

LSU Doctoral Dissertations

With the increasing complexity of asphalt mixture composition, the current volumetric-based Superpave mixture design would not be sufficient to address durability concerns. To address this limitation, performance-based testing is introduced to supplement conventional volumetric mixture design in assessing the cracking resistance of asphalt mixtures. To perform cracking tests, samples need to be aged to represent the most embrittlement case. The current AASHTO standard for asphalt mixture long-term aging (LTA) is a 5-day oven-aging at 85°C. Quality control/assurance practices require samples to be long-term aged prior to a cracking test which is a time-consuming process. Therefore, it would be beneficial to …

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 …

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 …

Resource And Energy Recovery From Wastewater Using Advanced Bioelectrochemical Systems, Sidan Lu

LSU Doctoral Dissertations

Water pollution and energy depletion are two critical issues in the world that limit the sustainable development of human society. In this study, several advanced (photo) bioelectrochemical systems (BESs) were proposed for effective energy (electricity and H₂) and nutrients (N and P) recovery from wastewater, solar energy, seawater, and river water. The first study demonstrated high effectiveness of a novel resource-recovery microbial fuel cell (RRMFC) for wastewater treatment and nutrient recovery from synthetic urine-containing wastewater. Over one cycle (∼3 days), 99% of urea, 97% of COD, 99% of histidine, 91% of creatinine, 99% of sodium acetate, 98% of …

Educational Theory-Embedded Training For Construction Industry Professionals, Hazem Jadallah

LSU Doctoral Dissertations

Workforce training is needed throughout the construction industry to create and maintain competent workers; unfortunately, most construction training and education research focuses on university student education. The focus of this dissertation research is the current state of educational-theory embedded construction workforce training, how such trainings are effective, and how they may be further optimized based on established educational theory. This is accomplished through a review of construction training for current industry professionals, an evaluation of the assessment criteria used to measure effectiveness, followed by the creation of a framework for construction training.

There is a lack of recommendations for improvement …

Water-Energy Nexus: Studies On Salinity Gradient Energy Harvest And Desalination, Guangcai Tan

LSU Doctoral Dissertations

Water and energy are fundamentally linked, and both are important for the development of human society. The demand for renewable energy and freshwater are two global challenges in the 21^st century. Herein, a novel chloride-ion (Cl⁻) concentration flow cell (CFC) based on two symmetrical electrodes (BiCl₃, CoCl₂, VCl₃, or BiOCl) separately by a cation-exchange membrane was used as an efficient method to recover salinity gradient (SG) energy. The CFC with metal chloride electrodes (BiCl₃, CoCl₂, and VCl₃) was based on Cl⁻ extraction/insertion, and that …