Civil and Mechanical Engineering Electronic Theses and Dissertations (UMKC)
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The items in this collection are the theses and dissertations written by students of the Department of Civil and Mechanical Engineering. Some items may be viewed only by members of the University of Missouri System and/or University of Missouri-Kansas City. Click on one of the browse buttons above for a complete listing of the works.
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Item Timely and uniform application of curing compound on concrete pavement(2025) Nkongolo, Etienne Beya; Kevern, John T.Concrete curing is a critical stage during construction for volume stability, long-term strength development, and ultimate durability. Poor curing can lead to shrinkage, scaling, and other durability issues. Proper concrete curing maintains sufficient moisture in the concrete and allows continuous hydration. The high surface are-to-volume ratio of concrete pavement is making it difficult to maintain a uniform moisture content throughout the pavement, therefore curing concrete will provide a better environment for concrete to develop uniform and equal hardened properties. While a variety of curing techniques can be used, including wet curing, internal curing, and forced chemical curing, membrane-forming curing compounds (MFCCs) are often the easiest and most cost-effective technique to minimize evaporation for pavements and slabs placed on grade. The application of MFCC has been adopted by States Department of Transportation (DOT). However, achieving a quality curing has been challenging because of the limitations of techniques that can be implemented on field to evaluate the effectiveness of curing compound application on concrete pavement in real time. Some states DOTs rely on the use of the calibrated white paper sheet examination or the experience of the engineer for evaluation of the curing compound application effectiveness. Additionally, most of the evaluation tests are performed on hardened concrete and not applicable or difficult to assess for fresh concrete in the field. This study has developed a test method embedded resistance that can measure curing effectiveness in real-time during the early age of concrete. The embedded resistance as a measure to assess drying behavior of fresh concrete to quantify the effectiveness of curing Embedded resistance is a technique that uses concrete moisture content to assess the effectiveness of curing compound effectiveness on concrete. Concrete goes through phase change from plastic phase to solid during the early age. This transition is mainly caused by the hydration reaction. During the early age of concrete cement reacts with water to produce hydration reaction products and the excess water evaporate due to drying, leading to concrete microstructure development. However, at early age the presence of moisture in concrete makes concrete less resistant to current flow, as the electrical current in concrete moves through the pore spaces. With time more pores spaces in concrete are filled up with hydration reaction products, subsequently concrete becomes more resistant to the current flow, as electrical conductivity ability of concrete depends on the conductivity of the fluids inside the interconnection of pores system, the degree of saturation of the concrete, and the permeability. Therefore, using the resistance technique to trace moisture content in concrete can be an important tool to assess curing compound application effectiveness on fresh concrete. The study evaluated the effect of curing compound applications rates and application time using the embedded resistance technique. Furthermore, this study investigated the effects of curing compound application time on freshly placed concrete, the effect of curing conditions as well on the performance of concrete cured before and after the initial setting time, and lastly the effect of curing compound application rates and uniformity during the application. Tests were indexed against the standard moisture loss testing in addition to a newly developed real-time assessment of moisture loss and curing by embedded resistance. Ultimately with the goal of providing a correlated measure of moisture loss from field measurements. Lastly, surface profile degree of hydration and the maturity curve were performed in this study to under the effect of curing compound application rates on degree of hydration and strength gain. The findings from this study demonstrated that resistance is able to distinguish between samples with and without curing compound and significant differences in drying observed between the surface and relatively shallow depths. Additionally, the testing techniques were able to differentiate between the quality and rate of curing compound application and evaluate performance across a variety of environmental conditions. These findings indicate that a resistance-based approach could be a low-cost and non-destructive technique to evaluate the effectiveness of curing compound applications in real-time. Additionally, the study showed that a correlation can be found between moisture retention test, degree of hydration and the embedded resistance test. Based on the findings the embedded resistance test could be a suitable replacement for moisture loss test the test is much simpler and quicker test to be performed both in the lab and in the field.Item From interfacial nanostructures to advanced constructs: harnessing surfactant self-assembly at liquid interfaces(University of Missouri--Kansas City, 2025) Amirfattahi, Saba; Niroobakhsh, ZahraLiquid-in-liquid 3D (LL3DP) printing offers a promising platform for fabricating soft material structures by depositing an ink phase within an immiscible support bath. While this technique enables the creation of complex architectures for applications in biomedical engineering, drug delivery, and tissue scaffolding, its broader potential is currently limited by the stability and tunability of the liquid-liquid interface. The primary focus of this work is to develop and stabilize structured liquid interfaces that can support and facilitate LL3DP, enabling more reliable and versatile printing of soft materials. By designing material systems with enhanced interfacial stability and responsiveness, this approach aims to expand the library of printable inks and unlock new possibilities for controlled soft matter fabrication. In the first studied system, we investigate the stabilization of the liquid–liquid interface to fabricate a bicontinuous interfacially jammed emulsion gel (bijel) using the LL3DP approach. The bijel consists of two interpenetrating, continuous phases of immiscible liquids, stabilized by the self-assembly of colloidal particles—primarily nanoparticles— at the liquid interface. The structural features of the printed bijel constructs are characterized using confocal and scanning electron microscopy (SEM), while their mechanical properties are evaluated through shear rheometry. Compared to other soft materials explored for LL3DP, bijel-based prints offer unique advantages, including interconnected hydrophobic and hydrophilic domains confined within defined geometries, along with tunable structural and rheological characteristics. In the second system, a novel material system based on lipid self-assembly is presented to stabilize water-oil interfaces as the underlying mechanism in the LL3DP. The stabilization process, governed by the formation of nanostructures at the interface, is comprehensively analyzed using small-angle X-ray scattering (SAXS), rheometry, and microscopy techniques. This material system, once incorporated successfully in LL3DP, enables the fabrication of intricate 3D constructs, including fibers, substrates, and microneedle patches, which demonstrate exceptional mechanical properties and biocompatibility, as validated by tensile testing and cell viability assays. Finally, the incorporation of silica nanoparticles into a material system previously established for soft matter 3D printing is presented, which was shown to result in the formation of aerogels with significantly enhanced mechanical strength and stability. Such silica aerogels, known for their ultralight weight and high porosity, tend to reinforce the liquid-phase structures while preserving flexibility. Upon further characterization, SAXS measurements confirm improved nanostructural organization in these aerogels, while rheological properties are comprehensively characterized. The development of these aerogels with hierarchical ordering across multiple length scales opens new possibilities for designing high-performance, multifunctional materials for medical implants, tissue engineering scaffolds, and filtration systems. This thesis, by bridging 3D printing and interfacial stabilization through selfassembly of various colloidal components such as inorganic (silica) nanoparticles and small amphiphilic molecules, lays the foundation for future advancements in soft material fabrication. The precise control over liquid-phase architectures and their tailored mechanical properties, as well as structural ordering at various scales, offers new possibilities for designing new class of materials for medicine, biotechnology, and advanced manufacturing.Item Surrogate learning for scoured bridges for capacity prediction with climate-scenario deep uncertainties(2025) Qadir, Ilham; Chen, ZhiQiangWaterway bridges are among the most vulnerable components of transportation infrastructure due to scour—the erosion of soil around foundations caused by flowing water—a risk expected to grow under climate-driven increases in flood intensity. Traditional fragility models often assume a fixed structural capacity, overlooking how scour alters soil–foundation–structure interaction (SFSI) and degrades performance.This study develops a computationally efficient surrogate-learning framework, trained on nonlinear pushover analyses, to predict yield-level transverse capacities—base shear, deck displacement, base moment, and column rotation—collectively expressed as a capacity tuple. To incorporate deep uncertainty arising from future IPCC climate-scenario trajectories, we employ a credal-set approach that yields upper and lower bounds on capacity predictions. The resulting method enables rapid, risk-informed evaluation of scour-critical bridges, supporting practical decision-making under uncertain future hydraulic hazards.Item Integrating supplemental lift devices to improve performance in high speed multi rotor UAVs(2025) Hofer, Nehemiah Craig; Abdulrahim, MujahidThis thesis investigates the integration of supplemental lift devices, implemented as fixed wings located generally aft of the vehicle’s center of gravity and lacking control surfaces, into high-speed multi-rotor UAVs. The goal is to improve flight performance across the diverse range of mission profiles these platforms typically encounter. Multi-rotor platforms are traditionally constrained by the need for their propellers to generate both lift and thrust, which limits flight time, top-end speed, and distance. To address these limitations, a detailed analysis of flight regimes was conducted to identify conditions where supplemental lift can offload vertical force production—as well as drag-induced moments—from the propellers. A FlightStream-based computational fluid dynamics simulation process, paired with a custom trim solver, was developed to balance aerodynamic forces and moments across a wide angle-of-attack sweep in order to find a trimmed solution. A controller-based approach was used to solve for trimmed conditions, offering flexibility and faster CFD run times. Informed by Latin Hypercube Sampling to explore the design space efficiently, a series of mission-specific design cases were created, testing different wing geometries and placements. Results showed that properly implemented supplemental lift can significantly reduce power draw during forward flight. The highest-performing configurations demonstrated a more than twofold increase in flight time relative to baseline quadrotors, a 33\% improvement in maximum flight distance, and enhanced dynamic capability with deck angles reaching 85 degrees and elevated top speeds across all mission profiles. This performance gain is largely attributed to the supplemental lift device reducing the burden on the propellers to generate both lift and stabilizing moments. By offloading these functions, overall power requirements decrease, allowing excess power to be redirected toward propulsion or maneuvering, depending on mission demands. This work demonstrates that carefully tailored lift surfaces, guided by system-level trimming tools and simulation-informed mission analysis, can meaningfully enhance UAV endurance and performance.Item The role of gypsum in Cu-Co ore genesis within the Upper Miocene Boleo deposit of the Santa Rosalía Basin, Baja California Sur, México(2025) Salgado Munoz, Valente O.; Niemi, Tina M.; Chen, ZhiQiangThis dissertation presents research on the geology, mineralization, and fluid evolution of the Boleo deposit in the Santa Rosalía basin, focusing on the role of evaporite bodies and fault networks in cobalt mineralization. The lithofacies description and sedimentological analysis of Boleo gypsum in Arroyo Boleo reveal a meromictic continental basin environment with cyclic deepening and shallowing trends driven by tectonic subsidence and marine incursions. Mineralization at the top of clastic sediments and the base of gypsum cycles indicates coeval deposition of evaporites and ores. The study identifies segmented normal fault arrays as feeder zones for metal-enriched hydrothermal fluids, with subsurface gypsum bodies acting as halogen suppliers. These feeders exhibit distinct metal tonnages and ratios, indicating proximity to the source. The dissertation also examines the physicochemical characteristics of fluids in the Boleo deposit, proposing a brine pool model with a magmatic fluid source for metals. The intricate zoning of metals indicates variations in major and trace metal composition within ore bed sediments, influenced by brine fluids and hydrothermal fluids. The research points out the importance of interdisciplinary collaboration and continued research efforts to improve our understanding of gypsum deposits for industrial use and to optimize their benefits.