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Full-Text Articles in Engineering

Behavior Of Prestressed Concrete Bridges With Closure Pour Connections And Diaphragms, Gercelino Ramos Oct 2019

Behavior Of Prestressed Concrete Bridges With Closure Pour Connections And Diaphragms, Gercelino Ramos

Masters Theses

Accelerated Bridge Construction (ABC) has gained substantial popularity in new bridge construction and bridge deck replacement because it offers innovative construction techniques that result in time and cost savings when compared to traditional bridge construction practice. One technology commonly implemented in ABC to effectively execute its projects is the use of prefabricated bridge components (precast/prestressed bridge components). Precast/prestressed bridge components are fabricated offsite or near the site and then connected on-site using small volume closure pour connections. Diaphragms are also commonly used to strengthen the connection between certain prefabricated components used in ABC, such as beam elements. Bridges containing closure …


Analysis Of Adhesive Anchorage Systems Under Extreme In-Service Temperature Conditions, Rachel Wang Mar 2019

Analysis Of Adhesive Anchorage Systems Under Extreme In-Service Temperature Conditions, Rachel Wang

Masters Theses

Adhesive anchorage systems have found widespread use in structural applications, including bridge widening, concrete repair and rehabilitation, and barrier retrofitting. Because these applications typically require adhesive anchorage systems to be installed outdoors, the effects of climate conditions and day-to-day temperature fluctuations on adhesive behavior and performance should be considered. The purpose of this thesis is to simulate pullout tests of adhesive anchorage systems for threaded rod and reinforcing bars and to emulate effects under various temperature conditions through the use of finite element analysis. Results from the finite element simulation are then compared to the physical tests conducted at UMass …


Abrasion Resistant Concrete Mix Design For Cold Climates, Diane Mariah Murph Jan 2019

Abrasion Resistant Concrete Mix Design For Cold Climates, Diane Mariah Murph

Masters Theses

“Studded tire usage in Alaska contributes to rutting damage on pavements resulting in high maintenance costs and safety issues. In this study, binary, ternary, and quaternary highly-abrasion resistant concrete mix designs using supplementary cementitious materials (SCMs) were developed. The properties of fresh concrete and mechanical, and durability properties of hardened concrete for these mix designs were then tested to determine an optimum highly-abrasion resistant concrete mixture which could be placed in cold climates to reduce rutting damage. SCMs used included silica fume, ground granulated blast furnace slag, and type F fly ash. Tests including workability, air content, drying shrinkage, compressive …


Performance Of One-Part And Two-Part Class C Fly Ash-Based Alkali Activated Mortars, Cedric Chani Kashosi Jan 2019

Performance Of One-Part And Two-Part Class C Fly Ash-Based Alkali Activated Mortars, Cedric Chani Kashosi

Masters Theses

“Seeking an eco-friendly concrete, researchers have conducted studies to fully replace ordinary Portland cement (OPC) with fly ash (FA) producing alkali-activated concrete (AAC). Results showed better performance of AAC in terms of high early compressive strength, and durability compared to conventional concrete. However, much is still unknown about the behavior of AAC. From the type of materials used, the curing procedure, and long-term strength development of these binders; a thorough investigation is needed in order to fill the existing gap from previous studies and thus make a step forward to the safely use of AAC in the construction industry. The …


Feasibility Study For Sustainable Controlled Low-Strength Material (Clsm) Incorporating Off-Specification Fly Ash And Bottom Ash, Alexis K. Vandomelen Jan 2019

Feasibility Study For Sustainable Controlled Low-Strength Material (Clsm) Incorporating Off-Specification Fly Ash And Bottom Ash, Alexis K. Vandomelen

Masters Theses

“Controlled low-strength material (CLSM) is a self-consolidating cementitious material used in applications requiring high flowability and low strength. The primary components of this material, being cement and sand, however, negatively impact the environment. Cement is a large contributor to CO2 emissions, and the vast depletion of sand causes physical and political issues. Furthermore, over 100 million short tons of coal combustion products (CCP), including fly ash and bottom ash, are created annually in the United States, while nearly half of all CCP remain unused. No off-specification fly ash has been implemented in CLSM. This study uses coal ashes sourced from …


Unmanned Aerial And Traversing Vehicle -- A Mobile Platform For Bridge Inspections, Clayton A. Fritsche Jan 2019

Unmanned Aerial And Traversing Vehicle -- A Mobile Platform For Bridge Inspections, Clayton A. Fritsche

Masters Theses

“Unmanned aerial vehicles (UAVs), also known as drones, have been rapidly growing in popularity since their creation. This study aimed to create a robotic platform used to assist in the inspection process of the nation’s aging and deteriorating bridges. To this end, a multimodal inspection robot that utilized both flying and driving technologies, was designed, analyzed, and tested for aerial, traversing, and their transitional operability. The design, herein referred to as the “BridgeBot”, was evaluated both computationally and experimentally. A finite element model of the BridgeBot was established and analyzed under static loading scenarios to help determine stress distributions and …


Development Of Test Methods For Characterizing Extrudability Of Cement-Based Materials For Use In 3d Printing, Jonathan Thomas Kuchem Jan 2019

Development Of Test Methods For Characterizing Extrudability Of Cement-Based Materials For Use In 3d Printing, Jonathan Thomas Kuchem

Masters Theses

"3D printing is the process of creating three-dimensional objects using an automated additive manufacturing process. The 3D printing process has been used with materials such as metals and polymers, but application with cement based materials for the construction industry has yet to be developed. In this research, two main problems were investigated for printing cement based composite materials: extrudability and tensile reinforcement. Fiber-reinforced concrete (FRC) was studied as an internal reinforcing system to increase tensile/flexural strength. First, FRC was studied to investigate mechanical properties and use of fibers from waste tires as an environmentally friendly option. A reference mixture with …


A Study On End-Anchorage And Bond Behavior Of Steel-Fiber Reinforced Cementitious Matrix Composites Externally Bonded To A Concrete Substrate, Christopher Michael Moore Jan 2019

A Study On End-Anchorage And Bond Behavior Of Steel-Fiber Reinforced Cementitious Matrix Composites Externally Bonded To A Concrete Substrate, Christopher Michael Moore

Masters Theses

"Fiber reinforced cementitious matrix (FRCM) composites are a strengthening material consisting of continuous fibers embedded in an inorganic matrix that have the potential to provide additional flexural and shear strength to concrete and masonry members. When used for external strengthening, however, debonding of the material is often observed due to slippage of the fiber with respect to the matrix, causing loss of composite action and a reduction in load carrying capacity. The composite utilized in this study consisted of continuous steel fibers embedded in an inorganic cementitious matrix bonded to a concrete prism. Additionally, an end-anchorage system was implemented with …


Changes In Fresh Properties Of Flowable Concrete Induced By Pumping And Composition Of The Lubrication Layer, Alexis Salinas Jan 2019

Changes In Fresh Properties Of Flowable Concrete Induced By Pumping And Composition Of The Lubrication Layer, Alexis Salinas

Masters Theses

"Pumping is an easy method to move concrete while keeping stability. It is worldwide accepted as one of the principal methods for concrete placement, as it accelerates construction. Typically, concrete acceptance in terms of fresh quantitative empirical properties (i.e. slump/slump flow and air content) are performed prior to the pumping process. However, empirical measurements have the drawback that they only measure 1 point. Rheology is better tool to evaluate the behavior of concrete. Pumping is a process that induces considerable shearing in the concrete that can impact its rheological properties. Therefore, the magnitude of these changes in fresh properties depends …