Engineering Commons^™

The Compressive And Flexural Strength Of Concrete Containing Recycled Waste Plastic, Isaiah Akinkunmi

Master of Science in Civil Engineering Theses

Annually, tons of plastic wastes end up in landfills and the oceans through indiscriminate dumping, constituting a major source of pollution to the environment and threat to human health and marine lives. It therefore necessitates an innovative strategy to help mitigate the environmental hazards caused by this pollution. A feasible eco-friendly strategy is by using granulated plastics, fibers or regrinds in concreting. This research explored the feasibility of this strategy by testing the compressive and flexural strengths of hardened concrete specimens containing varying percent of plastic aggregates used as partial replacement for fine aggregates. The compressive strength of specimens of …

An Investigation Into The Effects Of Fly Ash On Freeze-Thaw Durability Prediction, Yancy Schrader

Graduate Theses and Dissertations

Air is purposefully entrained into concrete primarily to improve resistance to freeze-thaw deterioration while saturated with water. Air entraining admixtures (AEAs) are chemical admixtures designed to entrain air into the concrete to provide adequate resistance to the effects of freezing and thawing. One of the challenges associated with air entrainment in concrete is the interaction of an AEA with supplementary cementitious materials present in the concrete, particularly fly ash. Fly ash is a by-product of the coal fired electrical generation industry, and often contains residual unburned carbon and other components that can increase the AEA demand of a particular concrete …

Hydration, Shrinkage, Cracking, And Mechanical Properties Of Cementitious Materials With Lignocellulosic Biomass Wastes., Aofei Guo

Electronic Theses and Dissertations

The disposal of lignocellulosic biomass wastes imposes a huge economic and environmental burden on this society. Recycling lignocellulosic biomass wastes and applying them to cementitious materials provides a sustainable and value-added way for both agriculture and concrete industries. To comprehensively identify the effect of lignocellulosic biomass wastes at different scales on cementitious materials, the hydration, shrinkage, cracking, and mechanical properties of cementitious materials with lignocellulosic biomass wastes were studied. Given the three different forms (powders, chips, and fibers) of lignocellulosic biomass wastes in this study, the research was implemented in three stages. In the first stage, hemp powders were collected …

Machine Learning Prediction Of Shear Capacity Of Steel Fiber Reinforced Concrete, Wassim Ben Chaabene

Electronic Thesis and Dissertation Repository

The use of steel fibers for concrete reinforcement has been growing in recent years owing to the improved shear strength and post-cracking toughness imparted by fiber inclusion. Yet, there is still lack of design provisions for steel fiber-reinforced concrete (SFRC) in building codes. This is mainly due to the complex shear transfer mechanism in SFRC. Existing empirical equations for SFRC shear strength have been developed with relatively limited data examples, making their accuracy restricted to specific ranges. To overcome this drawback, the present study suggests novel machine learning models based on artificial neural network (ANN) and genetic programming (GP) to …

Strength Restoration Of Corrosion Damaged Piles Repaired With Carbon Fiber Reinforced Polymer Systems, Jethro Clarke

USF Tampa Graduate Theses and Dissertations

Of the 12,741 bridges accounted for by the Florida Department of Transportation (FDOT), approximately 50% were built between the 1950s and 1960s. During this period, bridges were typically constructed in coastal environments using pile bents. Now, the main threat to bridges in these environments is corrosion, which occurs in the splash zones of most bridge piles. These zones contain high concentrations of chlorides, oxygen and moisture, the corner stones of a highly corrosive environment. Corrosion compromises steel reinforcement in these areas leading to cracking, spalling and an inevitable loss of capacity.

In recent years, significant strides have been made in …

Development Of A Framework For The Calibration Of Rpas, A 3d Finite Element Analysis Tool For Rigid Pavements, Abbasali Taghavighalesari

Open Access Theses & Dissertations

The accurate analysis of rigid pavements requires a reliable modeling procedure based on integrating mechanistic analysis methods (i.e. closed-form solutions or numerical methods) and empirical observations (i.e. field measurements and laboratory test results). The use of the finite element method to model the response of rigid pavements has increased in recent decades due to its capability to incorporate the complexity of material behavior, traffic information, and environmental condition. Researchers from the University of Texas at El Paso developed the software Rigid Pavement Analysis System (RPAS) to comprehensively analyze the response of concrete pavements under different geometric configurations, foundation models, temperature …

Review Of Modern Nondestructive Testing Techniques For Civil Infrastructure, Shabnam Khanal

Graduate Theses, Dissertations, and Problem Reports

The repair and maintenance of aging infrastructures, in the United States alone, are estimated to have backlogs of trillions of dollars. This has posed widespread concerns about the existing and proposed infrastructures to adequately sustain the quality of life in the near future. Efficient and cost-effective approaches, such as nondestructive testing (NDT), are therefore required to better shape our future. Various NDT techniques have been developed over the past two decades with cutting-edge advances towards investigation and condition assessment of civil infrastructures. While the performance of NDT techniques has reached unparalleled heights, limitations remain. On one side, are the instrument …

Bond Behavior Of Advanced Fiber Reinforced Composite-Concrete Joints, Xingxing Zou

Doctoral Dissertations

“Externally bonding advanced composite materials to concrete structures is an effective way to improve their strength, ductility, and durability. The interfacial bond behavior is fundamental to understand the overall structural performance of concrete structures strengthened with advanced composite materials. This study includes a comprehensive investigation of the bond behavior of composite-concrete joints with different fiber reinforced composite types. First, a direct approach to determine the bond-slip relationship for fiber reinforced cementitious matrix (FRCM)-concrete joints based on fiber strain measurements was proposed. Then, an analytical solution to predict the full-range response of FRCM-concrete joints was derived by assuming a trilinear bond-slip …