Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 5 of 5

Full-Text Articles in Engineering

Long-Term Performance Of Sustainable Pavements Using Ternary Blended Concrete With Recycled Aggregates, Seth M. Wagner Aug 2019

Long-Term Performance Of Sustainable Pavements Using Ternary Blended Concrete With Recycled Aggregates, Seth M. Wagner

Theses and Dissertations

The purposes of this study were to (a) design concrete pavement mixtures with recycled concrete aggregates using ternary blends of cementitious materials and a low water-to-binder ratio, (b) measure the fresh and hardened properties of the proposed concrete mixtures and (c) assess the long-term performance of the concrete implementing the use of recycled coarse aggregates. Preliminary investigation into ternary blend combinations via the compressive testing of mortar cubes and isothermal calorimetry was used to predict an optimal blend of cementitious material. Mixes using recycled concrete aggregates at varying replacement rates were tested for fresh and hardened properties using the proposed …


Design And Predicting Performance Of Carbon Nanotube Reinforced Cementitious Materials : Mechanical Properties And Dispersion Characteristics., Mahyar Ramezani Aug 2019

Design And Predicting Performance Of Carbon Nanotube Reinforced Cementitious Materials : Mechanical Properties And Dispersion Characteristics., Mahyar Ramezani

Electronic Theses and Dissertations

Recently, Carbon Nanotubes (CNTs) are drawing considerable attention of researchers for reinforcing cementitious materials due to their excellent mechanical properties and high aspect ratio (length-to-diameter ratio). However, CNTs might not disperse well within the cement matrix, resulting in little improvement or even degradation of concrete properties. The uncertainty in producing the consistent results in different studies might be attributed to multiple interactions between the experimental variables affecting the nanotube dispersion and the final properties of CNT-cement nanocomposites. Therefore, this research mainly focused on proposing equations that can reliably capture these interactions in order to correlate CNT dispersion with the mechanical …


Morphology And Detection Of Corrosion On Stainless Steel Reinforcement In Concrete, Julio J. Saire Yanez Jun 2019

Morphology And Detection Of Corrosion On Stainless Steel Reinforcement In Concrete, Julio J. Saire Yanez

USF Tampa Graduate Theses and Dissertations

Stainless steel (SS) has emerged as an alternative corrosion-resistant reinforcement in concrete instead of the commonly used carbon steel (CS). The biggest advantage of SS is that it takes more time for corrosion to initiate than for CS. An additional benefit from the use of SS in concrete may be derived from the period after the corrosion started until the concrete structure reaches a limit state. This period is called corrosion propagation stage (CPS) and it has been hardly studied in SS reinforced structures. The duration of this period could be related, among other factors, to the morphology of corrosion …


Short Beam Shear Strength Evaluations Of Gfrp Composites: Correlations Through Accelerated And Natural Aging, William Todd Barker Jan 2019

Short Beam Shear Strength Evaluations Of Gfrp Composites: Correlations Through Accelerated And Natural Aging, William Todd Barker

Graduate Theses, Dissertations, and Problem Reports

Fiber Reinforced Polymers (FRP) composites have been materials of interest in replacing or reinforcing steel, wood, and concrete, but lack of understanding of degradation under physical and chemical aging is a main concern. Through many years of research, the understanding of aging or durability of GFRPs has improved. To be able to evaluate aging related degradation rates, an accelerated aging methodology under varying environments is introduced. Accelerated aging is a concept used to age composites in a lab controlled environment under varying pH conditions (2 to 13) and temperatures (~ -20° to +160°F). Once acceleratedly aged testing is completed, Arrhenius …


Influence Of Pumping Parameters On The Freeze-Thaw And Scaling Resistance Of Highly Workable Concrete, Alexandra Nicole Wehar Jan 2019

Influence Of Pumping Parameters On The Freeze-Thaw And Scaling Resistance Of Highly Workable Concrete, Alexandra Nicole Wehar

Masters Theses

“Over the past 60 years, pumping concrete has gained popularity due to the economic and technical benefits that typically accompanies it. However, boom configuration and flow rate can adversely affect freeze-thaw and scaling resistance of concrete due to the effects of pressure on the air-void system. Therefore, the objective of this research is to assess the influence of different pumping parameters on the durability of hardened self-consolidating concrete. Self-consolidating, flowable, and conventional concrete mixtures were tested during large scale pumping experiments positioning the pump boom in an “A” and a flat shape as well as using different pumping speeds. In …