Open Access. Powered by Scholars. Published by Universities.®
- Institution
- Keyword
-
- Concrete (2)
- Finite element analysis (2)
- Incentives (2)
- 3D printing (1)
- Accelerated bridge construction (1)
-
- Additive manufacturing (1)
- Adhesive (1)
- Air-Void System (1)
- American Iron and Steel Institute (1)
- Anchor (1)
- Anchorage system (1)
- Anthropogenic (1)
- Articulated design (1)
- Bottom ash (1)
- Bridge (1)
- BridgeBot (1)
- CLSM (1)
- Closure pour connections (1)
- Cold-formed steel (1)
- Commuter Bus (1)
- Controlled low-strength material (1)
- Decked bulb tee girders (1)
- Diaphragms (1)
- Driver Behavior (1)
- Driving Simulation (1)
- Drone (1)
- Durability (1)
- Emissions Factors (1)
- Energy (1)
- Epoxy (1)
Articles 1 - 17 of 17
Full-Text Articles in Engineering
Behavior Of Prestressed Concrete Bridges With Closure Pour Connections And Diaphragms, Gercelino Ramos
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 …
The Promise Of Vr Headsets: Validation Of A Virtual Reality Headset-Based Driving Simulator For Measuring Drivers’ Hazard Anticipation Performance, Ganesh Pai Mangalore
The Promise Of Vr Headsets: Validation Of A Virtual Reality Headset-Based Driving Simulator For Measuring Drivers’ Hazard Anticipation Performance, Ganesh Pai Mangalore
Masters Theses
The objective of the current study is to evaluate the use of virtual reality (VR) headsets to measure driving performance. This is desirable because they are several orders of magnitude less expensive and, if validated, could greatly extend the powers of simulation. Out of several possible measures of performance that could be considered for evaluating VR headsets, the current study specifically examines drivers’ latent hazard anticipation behavior both because it has been linked to crashes and because it has been shown to be significantly poorer in young drivers compared to their experienced counterparts in traditional driving simulators and in open …
Sustainable Travel Incentives Optimization In Multimodal Networks, Hossein Ghafourian
Sustainable Travel Incentives Optimization In Multimodal Networks, Hossein Ghafourian
Masters Theses
Tripod, an integrated bi-level transportation management system, is a smartphone application from the potential user’s point of view which would be instantly accessed prior to performing the trip. Since there are constantly several alternatives for any trip, Tripod considers a series and combination of various parameters, including departure time, mode and route, and rewards for each alternative with a number of redeemable points for goods and services called “Tokens”. The framework responsible for computing the optimized number of tokens awarded to the set of available alternatives in order to minimize the system-wide energy consumption under a constrained Token budget, is …
Modeling The Effect Of New Commuter Bus Service On Demand And The Impact On Ghg Emissions: Application To Greater Boston, Christopher Lyman
Modeling The Effect Of New Commuter Bus Service On Demand And The Impact On Ghg Emissions: Application To Greater Boston, Christopher Lyman
Masters Theses
The transportation sector is considered one of the major contributors to greenhouse gas (GHG) emissions in metropolitan areas, and any efforts to reduce these emissions requires strategic management of multiple transportation modes. This paper presents a method to identify opportunities to reduce GHG emissions by expanding commuter bus services and incentives to shift commuters from private cars to transit. The approach uses a nested multinomial logit model for mode choice in a region that includes driving alone, carpooling, walking, cycling, and using four possible transit modes (ferry, commuter rail, rapid transit and bus) by walk access or driving access. A …
Analysis Of Adhesive Anchorage Systems Under Extreme In-Service Temperature Conditions, Rachel Wang
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 …
Performance Of Concrete Tunnel Systems Subject To Fault Displacement, Michael Morano
Performance Of Concrete Tunnel Systems Subject To Fault Displacement, Michael Morano
Masters Theses
A Finite Element Analysis (FEA) investigation of concrete tunnel systems traversing seismic faults is carried out to determine how to effectively mitigate the stresses induced in the liner when subject to fault displacement. A parametric study of various fault parameters, both in the damage zone and competent rock, is carried out to determine the site conditions which induce the most stress on the tunnel liner system. Results indicate that friction angle, cohesion, and elastic modulus of fault zones have varying effects on the stresses induced on the liner. The width of damage zone and expected displacements are also investigated and …
High Fidelity Modeling Of Cold-Formed Steel Single Lap Shear Screw Fastened Connections, Rita Kalo
High Fidelity Modeling Of Cold-Formed Steel Single Lap Shear Screw Fastened Connections, Rita Kalo
Masters Theses
Cold-formed steel connections are commonly fastened using self-tapping self-drilling screws. The behavior of these connections can differ based on the screw manufacturer or the cold-formed steel product used, both of which have a large selection available for use in industry. Because of their popularity and the many possible variations of these connections, researchers have frequently tested screw connections to characterize their behavior. However, repeatedly conducting this type of experiment is time consuming and expensive. Therefore, the purpose of this work was to create finite element models that can successfully predict the behavior of single lap shear screw connections, a common …
Influence Of Pumping Parameters On The Freeze-Thaw And Scaling Resistance Of Highly Workable Concrete, Alexandra Nicole Wehar
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 …
Performance Of One-Part And Two-Part Class C Fly Ash-Based Alkali Activated Mortars, Cedric Chani Kashosi
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 …
Unmanned Aerial And Traversing Vehicle -- A Mobile Platform For Bridge Inspections, Clayton A. Fritsche
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
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 …
Evaluation Of Naturally Occurring And Anthropogenic Contamination In Missouri Streams, Christina Jane Sehrt
Evaluation Of Naturally Occurring And Anthropogenic Contamination In Missouri Streams, Christina Jane Sehrt
Masters Theses
"The goal of this study is to observe the values and variability of water quality parameters and benthic macroinvertebrates in watersheds with very little anthropogenic impact and to compare these values with those acquired in watersheds with more anthropogenic impact. The following five HUC 12-digit watersheds had very little anthropogenic impact and were considered "pristine": Rogers Creek, Mill Creek, Middle West Fork-Black River, Bee Fork, and Ottery Creek. Five largely urban sub-basins were also considered; these basins are: Grand Glaize Creek, Glaize Creek, Sugar Creek, Hominy Creek, and Grindstone Creek. For each watershed, both water quality parameters and benthic macroinvertebrates …
Analysis Of Construction Fall Protection Guardrails In A Population With Changing Anthropometrics, Connor S. Klinzing
Analysis Of Construction Fall Protection Guardrails In A Population With Changing Anthropometrics, Connor S. Klinzing
Masters Theses
The construction trade has commonly been cited as one of the most dangerous industries within the United States, with falls from elevation being the most predominate cause for injuries and deaths. The OSHA standards related guardrails has not changed since its implementation in 1970. These standards originally derive from the 1950s, which expect a 160-pound person with 40 pounds of equipment, tools, etc. However, the anthropometries of the common working age citizen has dramatically changed in respects to their weight. This study examines the relationship of the guardrail system to the changing anthropometries to determine if a reform is necessary …
A Study On End-Anchorage And Bond Behavior Of Steel-Fiber Reinforced Cementitious Matrix Composites Externally Bonded To A Concrete Substrate, Christopher Michael Moore
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
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 …
Abrasion Resistant Concrete Mix Design For Cold Climates, Diane Mariah Murph
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 …
Feasibility Study For Sustainable Controlled Low-Strength Material (Clsm) Incorporating Off-Specification Fly Ash And Bottom Ash, Alexis K. Vandomelen
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 …