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Full-Text Articles in Engineering

Development Of A Mix Design Adjustment Method For Fiber Reinforced Concrete And Super High Performance Concrete Based On Excess Paste, Joe Malloy Dec 2019

Development Of A Mix Design Adjustment Method For Fiber Reinforced Concrete And Super High Performance Concrete Based On Excess Paste, Joe Malloy

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

The main objective of this study was to develop a mix design adjustment method for Fiber Reinforced Concrete (FRC) that would maintain appropriate workability while improving hardened concrete performance. A literature review was conducted to examine existing methods for adjusting mix designs to account for fiber introduction. It was found that while increasing fine aggregate and cement paste content can make up for lost workability with the addition of fibers, no rational mix design adjustment method is available. Reference mix designs from the Nevada Department of Transportation and the Nebraska Department of Transportation were used, and this study focused on …


Evaluation Of Internally Cured Bridge Deck Concrete With Standard And Optimized Aggregate Gradation, Arman Abdigaliyev Oct 2019

Evaluation Of Internally Cured Bridge Deck Concrete With Standard And Optimized Aggregate Gradation, Arman Abdigaliyev

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Due to the relatively high cement content and low water-to-cement ratio (w/c) used, bridge deck concrete is prone to premature cracking. Internal curing has been found to greatly reduce the chance of premature cracking as well as concrete deterioration. This research developed internally cured bridge deck concrete based on a local mix design in Nebraska. Four different lightweight fine aggregate (LWFA) as internal curing agents were evaluated and their effects on fresh, mechanical, durability, and shrinkage properties of concrete were studied. The study focused on resolving two issues associated with fine aggregate replacement based on Bentz equation. To identify the …


Uhpc Shear Keys In Concrete Bridge Superstructures, Craig Newtson, Brad Weldon, Elsy Flores, Jordan Varbel, William Toledo Aug 2019

Uhpc Shear Keys In Concrete Bridge Superstructures, Craig Newtson, Brad Weldon, Elsy Flores, Jordan Varbel, William Toledo

Publications

This research investigated the use of locally produced ultra-high performance concrete (UHPC) as a grouting material to repair deteriorated shear keys. Shear keys are used in adjacent girder superstructures to produce monolithic behavior and load transfer across the structure. Shear key durability is a concern since shear key degradation can jeopardize the integrity of the structure. Transportation agencies have reported that 75% of distress in adjacent girder bridges is due to cracking and de-bonding along shear keys. Previous research has shown that locally produced UHPC has excellent mechanical and durability properties. UHPC has also been shown to have good bonding …


Use Of Bagasse Ash As A Concrete Additive For Road Pavement Application, Gabriel Arce, Marwa Hassan, Maria Gutierrez, Michele Barbato Aug 2019

Use Of Bagasse Ash As A Concrete Additive For Road Pavement Application, Gabriel Arce, Marwa Hassan, Maria Gutierrez, Michele Barbato

Publications

The objective of this study was to evaluate the use of sugarcane bagasse ash (SCBA) as a partial replacement of cement in concrete for road pavement application. The study explored the pozzolanic activity of SCBA produced from three different processing methodologies (i.e., raw SCBA, controlled SCBA and post-processed SCBA). The experimental results revealed that SCBA produced by the controlled burning of sugarcane bagasse fiber (SBF) at 650°C and grinding (C-650), presented the maximum pozzolanic activity. However, this SCBA production process was deemed challenging for large-scale industrial application due to low SCBA yield (i.e., 3 to 6%). On the other hand, …


Retrofitting Of Bridge Elements Subjected To Predominantly Axial Load Using Uhpc Shell, Mahsa Farzad Apr 2019

Retrofitting Of Bridge Elements Subjected To Predominantly Axial Load Using Uhpc Shell, Mahsa Farzad

FIU Electronic Theses and Dissertations

In the United States, ~30% of the ~600,000 highway bridges are categorized as structurally deficient or functionally obsolete. These bridges should be replaced or upgraded to sustain the transportation needs of the growing public and private sectors of the U.S. economy. It is not uncommon for structures to have advanced levels of corrosion-induced damage where major repair and maintenance works are required. However, the transportation infrastructure may undergo disruption during rehabilitation causing interruption to critical economic public, civil and commercial activities. This mandates the development of new techniques and materials for accelerated rehabilitation and resilience. To address this issue, a …