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Adiabatic Temperature Rise And Durability Performance Of Slag Blended Concrete, Hai Zhu Mar 2023

Adiabatic Temperature Rise And Durability Performance Of Slag Blended Concrete, Hai Zhu

USF Tampa Graduate Theses and Dissertations

Performance and durability of slag blended concrete was investigated in this study focusing on slag and cement characteristics. Seven slags with variable Al2O3 content, Al2O3/MgO ratio and fineness were selected for investigation. The eight selected cements included ASTM Type I, Type I(HA), Type II(MH), Type II(MH)(HA), and Type IL(10 and 14). Cementitious materials studied here were subjected to a battery of tests including physical, chemical and mineralogical characterization. Performance and durability testing included heat of hydration measurements, sulfate optimization, external sulfate resistance, adiabatic temperature rise and chloride ingress.

Adiabatic temperature rise was assessed on 60% slag blended concrete, using Type …


Strength Restoration Of Corrosion Damaged Piles Repaired With Carbon Fiber Reinforced Polymer Systems, Jethro Clarke Oct 2020

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 …


Electrochemical Methods To Characterize Drilled Shaft Deficiencies, Sarah Jo Mobley Mar 2017

Electrochemical Methods To Characterize Drilled Shaft Deficiencies, Sarah Jo Mobley

USF Tampa Graduate Theses and Dissertations

In recent years drilled shafts have become the preferred foundation method for marine bridges. Typically, the drilled shaft is selected over traditional driven piles due to soil strata encountered, construction economy, increased lateral stiffness requirements, and/or vibration control considerations. The most critical component in drilled shaft construction is borehole stabilization. Wall sloughing or groundwater inclusion can have devastating effects on the strength of the finished shaft however recent research has shown that the materials, more specifically the slurry, used to accomplish stabilization may be having a negative impact on the durability of the finished product. This thesis investigates the durability …


Feasibility Of Cathodic Protection In Grouted Post Tensioned Tendons - Exploratory Model Calculations, Jacob Dharma Bumgardner Nov 2015

Feasibility Of Cathodic Protection In Grouted Post Tensioned Tendons - Exploratory Model Calculations, Jacob Dharma Bumgardner

USF Tampa Graduate Theses and Dissertations

Recent corrosion related failures of grouted post tensioned tendons, even after the introduction of improved grouts, have led to renewed interest in supplemental or backup means of corrosion control for these systems. A finite element model is presented to explore feasibility of impressed current cathodic protection of strand in grouted tendons. The model examines polarization evolution as function of service time and includes consideration of anode placement and size, grout porosity, pore water alkalinity, electrochemical species diffusivity and applied voltage on the polarization efficacy and durability of such a system. The exploratory model projections suggested that, within the context of …


Kelvin Probe Electrode For Contactless Potential Measurement On Concrete-Properties And Applications, Michael Thomas Walsh Jan 2013

Kelvin Probe Electrode For Contactless Potential Measurement On Concrete-Properties And Applications, Michael Thomas Walsh

USF Tampa Graduate Theses and Dissertations

The practical feasibility of using a Kelvin Probe as a novel reference electrode in the measurement of both potential and polarization pulse response of reinforcing steel in concrete is demonstrated. Potential values measured using a KP reflect greater stability and repeatability than can typically be attained with conventional reference electrodes. Duplicate reinforced concrete beam test specimens with well-differentiated centrally corroding rebar segments were analyzed using both the Kelvin Probe (KP) and a conventional Saturated Calomel Electrode (SCE). Potential profile maps were developed using potential values recorded under static conditions with both the SCE and the KP. Nominal polarization resistance was …


Lrfd Design Of Double Composite Box Girder Bridges, Purvik Patel Jun 2009

Lrfd Design Of Double Composite Box Girder Bridges, Purvik Patel

USF Tampa Graduate Theses and Dissertations

Conventional continuous steel bridges only exhibit composite behavior in the positive moment region. Similar composite action may also be achieved in the negative moment region by casting a bottom concrete slab between the points of inflection. Such a section is referred to as "double composite" since it is composite in both the positive and negative moment regions. Savings in double composite bridges arise because expensive steel is replaced by inexpensive concrete to carry compressive loads. Although double composite bridges have been designed and constructed since at least 1978 there has been limited research. Thus, current designs rely on existing provisions …


Methods To Improve Bond On Frp Wrapped Piles, Andy Schrader Jun 2007

Methods To Improve Bond On Frp Wrapped Piles, Andy Schrader

USF Tampa Graduate Theses and Dissertations

Fiber Reinforced Polymer (FRP) sheets can provide incredible structural strength while weighing only a fraction as much as steel. When applied to piles the FRP provides strengthening through both concrete confinement and tensile reinforcement. Mainly used in structural repair, its application is relatively simple in theory. However, many factors(some avoidable, some not) can interfere with the bond between FRP and concrete. When this bond is interrupted the strength of the repair becomes compromised.This thesis examines 2 new methods of improving FRP bond to concrete piles during the time the resin is curing. These methods are compared using 3 types of …