Civil Engineering Commons^™

Shear Friction Capacity Of Corrugated Pipe Connection In Precast Footings, Fatima C. Vieira

FIU Electronic Theses and Dissertations

Prefabricated Bridge Elements and Systems (PBES) are being more widely used, as they can significantly reduce on-site construction time impacting traffic. The main concerns when using PBES are the final assembly of the elements to achieve the monolithic behavior of the structure. The currently recommend connection detail between the precast pile cap and precast pile is a pocket connection, which relies on the bearing strength between the end of the pile and pile cap and the shear friction capacity between the cast in place (CIP) plug and the precast cap. Current code expressions for shear friction include components for cohesion …

New Connection Details For Concrete Filled Tubes To Precast Concrete Elements For Accelerated Bridge Construction Applications, Fnu Sheharyar E Rehmat

FIU Electronic Theses and Dissertations

The synergistic interaction of steel and concrete in concrete filled tube (CFT) composite members improves structural performance by delaying local buckling of steel tube. Compared to localized confinement provided by discreet ties in reinforced columns, the steel tube provides continuous confinement to infill concrete which results in improved energy dissipation and ductility performance. Concrete filled tubes (CFTs) provide improved structural strength and ductility while minimizing the cost of column formwork. The construction sequence of CFT allows its use for accelerated bridge construction applications. The use of CFTs for bridges in the U.S. has been limited mainly due to lack of …

Experimental Analysis And Numerical Investigation Of Aerodynamics Of Elevated Structures, Nourhan Abdelfatah

FIU Electronic Theses and Dissertations

The vulnerability of low-rise residential buildings to extreme wind events, such as hurricanes, is an escalating concern due to the frequent failures and losses. Elevated low-rise structures are constructed to reduce the hydrodynamic load from surges and flooding during hurricanes. However, due to the current lack of information, wind loading on elevated coastal structures is not adequately addressed in current international guidelines. To address this knowledge gap, large-scale experimental studies were conducted to precisely determine wind effects on elevated houses with different numbers of stories and varying stilt heights. In this study, comparisons are presented on various tested configurations to …

Development Of The Uhpc Mix For 3d Printing, Buse Ilayda Oz

FIU Electronic Theses and Dissertations

This thesis utilizes the development of Ultra-High-Performance Concrete mix design for 3-Dimensional (3D) Printing purposes. 3D concrete printing offers many advantages such as the improvements in safety, quality, and productivity. Moreover, it holds a great advantage for the construction of structural elements that are difficult to construct by conventional methods. These advantages carry a huge potential for solving the aforementioned challenges.

Seven UHPC mixes have been designed and analyzed using various test setups for comparison purposes. Extrudability, flowability, buildability, and open time were measured using the fresh properties of the UHPC mixes. Mechanical properties were measured using compression test setups. …

Epoxy Glass Fiber Reinforced Plastic Dowel Splice For Prestressed Precast Concrete Pile, Saman Farhangdoust

FIU Electronic Theses and Dissertations

Due to limitations in operation, shipping difficulties, and unforeseen soil conditions, it often happens that splicing of precast-prestressed concrete pile (PPCP) segments has to be performed at the construction site to achieve longer lengths. In order to splice PPCPs, Glass fiber reinforced polymer (GFRP), Carbon Fiber Reinforced Polymer (CFRP), and Stainless Steel (SS) dowels can be used as corrosion-resistant bars. In addition to their durability and superb mechanical performance, GFRP bars show cost advantage when compared to other corrosion-resistant materials. The objective of this study is to investigate the flexural behavior and effectiveness of the GFRP dowel and compare its …

Full-Scale Experimental Modeling To Study Wind-Induced Vibrations, Wind Driven Rain And Their Effects On Curtainwall Window Systems, Krishna Sai Vutukuru

FIU Electronic Theses and Dissertations

Lewis Fry Richardson famously summarized turbulence as big whirls have little whirls, that feed on their velocity and little whirls have lesser whirls, and so on to viscosity. Big whirls/eddies typically affect the whole building structure whereas small eddies cause local area pressures causing damage to building components. Oncoming wind may carry high energy content due to these small eddies in the high-frequency range and sometimes these frequencies fall in the range of natural frequency of building components. These small eddies may cause response amplification due to this resonance, which is currently not considered in design codes such as ASCE …

Development Of An Ultra-High Performance Concrete Joint Detail For Short-Span Bridges, Francisco De Jesus Chitty Gozalo

FIU Electronic Theses and Dissertations

Slab beam superstructures have been used for short-span bridges since prestressed concrete began to be used in the US. Poor joint performance of these superstructures led to recent revisions to design standards; one example being the Florida Slab Beam (FSB). The FSB and other similar slab beam systems include a composite cast-in-place (CIP) reinforced concrete deck and joint between adjacent beams. An optimized joint design has been developed to accelerate the construction times and eliminate the need for a CIP deck by using ultra-high performance concrete (UHPC) in the longitudinal closure pour to connect the precast members.

The optimized joint …

Improving The Long-Term Performance Of Full-Depth Precast Concrete (Fdpc) Deck Panels Using Non-Proprietary Uhpc, Esmail Shahrokhinasab

FIU Electronic Theses and Dissertations

Full-depth precast concrete (FDPC) deck panels are a type of prefabricated bridge element used in accelerated bridge construction (ABC) that have been used in bridge construction since the 1960’s as an alternative to conventional CIP decks. The main purpose of using the prefabricated elements is to accelerate the construction and increase the long-term performance. FDPC deck panels itself offers superior durability and performance, but the connection between these elements still have shown some long-term issues like cracking. Ultra-high-performance concrete (UHPC) is an innovative and commercially available material that has been used to address concerns related to connection between precast elements. …

Aeroelastic Testing To Evaluate Wind Effects On Transmission Systems, Ziad Azzi

FIU Electronic Theses and Dissertations

The transmission infrastructure in the U.S. faces substantial risk from hurricanes. Wind-induced damage poses an immense threat to the electric power grid; such hazards have significantly impacted the supply, generation, and delivery of power to large portions of the U.S. in the past. When exposed to strong winds, critical demands in several elements in transmission tower-line systems may exceed corresponding capacities and trigger various modes of failure. Enhancing the resilience of the transmission grid against increasing threats from hurricanes and strong winds is therefore of critical importance. The results of 1:50 aeroelastic scaled models of a self-supported steel lattice tower …

Retrofitting And Rehabilitation Of Bridge Components Subjected To Predominantly Flexural Load Using Thin Uhpc Shell, Alireza Valikhani

FIU Electronic Theses and Dissertations

The number of bridges exceeding their design life is increasing every year and Federal Highway Administration estimates that structurally deficient and functionally obsolete bridges comprise almost 24% of total bridge inventory in the U.S. Besides aging, the existing bridges can sustain damages due to various factors including exposure to severe environment, deleterious chemicals, and overloading. To avert any catastrophic loss of property and life, it is imperative that the existing bridge inventory is rehabilitated and repaired at a minimal cost and at an expedited schedule using advanced construction methodologies and materials.

One such advancement consists of the use of Ultra-High …

Corrosion Durability Of A Nano-Particle Enriched Zinc-Rich Coating System For Highway Steel Bridges, Saiada Fuadi Fancy

FIU Electronic Theses and Dissertations

Corrosion is a major concern for the long-term durability and structural integrity of steel components of highway bridges when unprotected. The application of protective coatings has been widely used for corrosion mitigation of atmospherically exposed structural steel. At present, the zinc-rich primer (ZRP) based three-coat system is widely used in the United States. The metallic zinc pigment ideally would provide corrosion resistance by sacrificial as well as barrier protection. The life of these coating systems is at best only half of the bridge design life. Furthermore, premature degradation may occur if there are flaws in the system due to improper …

New Connection Details To Connect Precast Cap Beams To Precast Columns Using Ultra High Performance Concrete (Uhpc) For Seismic And Non-Seismic Regions, Mohamadreza Shafieifar

FIU Electronic Theses and Dissertations

Several connection details have been developed for the connection of precast cap beams to precast columns in Accelerated Bridge Construction (ABC) applications. Currently, the suggested details involve some form of either reinforcement or portion of the precast column to penetrate inside the cap beam. Such details present many challenges in the field, such as necessitating bundling of reinforcement in the cap beam or creating a congested reinforcement arrangement. Furthermore, closer inspection of some of the test data indicates that for currently used details, cap beams could sustain some damages during major seismic events, whereas they are designed to be capacity …

Study On Strut And Node Behavior In Strut-And-Tie Modeling, Nazanin Rezaei

FIU Electronic Theses and Dissertations

The strut-and-tie method (STM) is a simple and conservative method for designing concrete structures, especially deep beams. This method expresses complicated stress patterns as a simple truss or kinematic model made up of compression elements (struts), tension elements (ties), and the joints between elements (nodes). STM is based on lowerbound plasticity theorem, so using it properly will lead to a conservative design. Although the concepts of STM have been around in concrete design since the late 19th century, STM was first introduced in AASHTO LRFD in 1994 and ACI 318-02 in 2002. ACI 318 defines two different types of struts …

Investigating Scale Effects On Analytical Methods Of Predicting Peak Wind Loads On Buildings, Mohammadtaghi Moravej

FIU Electronic Theses and Dissertations

Large-scale testing of low-rise buildings or components of tall buildings is essential as it provides more representative information about the realistic wind effects than the typical small scale studies, but as the model size increases, relatively less large-scale turbulence in the upcoming flow can be generated. This results in a turbulence power spectrum lacking low-frequency turbulence content. This deficiency is known to have significant effects on the estimated peak wind loads.

To overcome these limitations, the method of Partial Turbulence Simulation (PTS) has been developed recently in the FIU Wall of Wind lab to analytically compensate for the effects of …

Experimental Investigation Of Wind-Induced Response Of Span-Wire Traffic Signal Systems, Manuel A. Matus Mr.

FIU Electronic Theses and Dissertations

The purpose of this investigation was to identify key design parameters that might significantly affect the response of span wire traffic light systems during extreme wind events. The performance of these systems was assessed through physical testing in an effort to quantify the effect of sag ratio, wire tension and wire clearance. The Wall of Wind experimental facility at Florida International University was utilized for testing the systems at different wind speeds and wind directions.

The findings showed that, at all tested wind directions, lift, drag and tension forces increased with increasing wind speeds. On the contrary, increasing the wind …

3-D Dynamic Analysis Of High-Speed Railroad Track, Mohammad Fesharaki

FIU Electronic Theses and Dissertations

High-Speed Rail (HSR) as a fast, reliable and environmentally friendly mode of transportation has received a lot of attention in recent decades. The International Union of Railways reported that there are more than 18600 miles of HSR in operation and about 1.6 billion passengers per year are carried by them. Although there are plans for HSR in many states including Florida, the United States, however, is still hesitant to develop its own HSR network. One of the main barriers to developing high-speed rail is excessive vibration propagation to the media which may cause annoyance to people who live in the …

Database-Assisted Analysis And Design Of Wind Loads On Rigid Buildings, Filmon Fesehaye Habte

FIU Electronic Theses and Dissertations

The turbulent nature of the wind flow coupled with additional turbulence created by the wind-building interaction result in highly non-uniform, fluctuating wind-loading on building envelopes. This is true even for simple rectangular symmetric buildings. Building codes and standards should reflect the information on which they are based as closely as possible, and this should be achieved without making the building codes too complicated and/or bulky. However, given the complexity of wind loading on low-rise buildings, its codification can be difficult, and it often entails significant inconsistencies. This required the development of alternative design methods, such as the Database-Assisted-Design (DAD) methodology, …

On The Role Of The Pore Water Chemistry Of Deficient Post-Tension Grout To Promote Steel Corrosion, Samanbar Permeh

FIU Electronic Theses and Dissertations

Corrosion failure of post-tension tendons with pre-packaged thixotropic grout was documented in Florida Bridges in less than 10 years of service. Analysis of deficient grout in Florida post-tensioned (PT) bridges where severe corrosion developed indicated enhanced sulfate ion concentration, high pore water pH, enhanced moisture and low chloride content. The corrosion wasn’t consistent with the conventional causes of steel corrosion such as bleed water accumulation in grout void spaces, chloride contamination and pore water carbonation. Corrosion development was associated with deficient grout with enhanced sulfate levels. However, limited information is available on the corrosion behavior of PT strand in grout …

Use Of Fiber Reinforced Polymer Composite Cable For Post-Tensioning Application, Xiong Yang

FIU Electronic Theses and Dissertations

Corrosion of steel tendons is a major problem for post-tensioned concrete, especially because corrosion of the steel strands is often hard to detect inside grouted ducts. Non-metallic tendons can serve as an alternative material to steel for post-tensioning applications. Carbon fiber reinforced polymer (CFRP), given its higher strength and elastic modulus, as well as excellent durability and fatigue strength, is the most practical option for post-tensioning applications.

The primary objective of this research project was to assess the feasibility of the use of innovative carbon fiber reinforced polymer (CFRP) tendons and to develop guidelines for CFRP in post-tensioned bridge applications, …

The Performance And Service Life Prediction Of High Performance Concrete In Sulfate And Acidic Environments, Shuo Zhang

FIU Electronic Theses and Dissertations

Concrete substructures are often subjected to environmental deterioration, such as sulfate and acid attack, which leads to severe damage and causes structure degradation or even failure. In order to improve the durability of concrete, the High Performance Concrete (HPC) has become widely used by partially replacing cement with pozzolanic materials. However, HPC degradation mechanisms in sulfate and acidic environments are not completely understood. It is therefore important to evaluate the performance of the HPC in such conditions and predict concrete service life by establishing degradation models.

This study began with a review of available environmental data in the State of …

Dynamic Behavior And Fatigue Life Of Highway Bridges Due To Doubling Heavy Vehicles, Arash Tarighi

FIU Electronic Theses and Dissertations

An increase in the demand for the freight shipping in the United States has been predicted for the near future and Longer Combination Vehicles (LCVs), which can carry more loads in each trip, seem like a good solution for the problem. Currently, utilizing LCVs is not permitted in most states of the US and little research has been conducted on the effects of these heavy vehicles on the roads and bridges. In this research, efforts are made to study these effects by comparing the dynamic and fatigue effects of LCVs with more common trucks.

Ten Steel and prestressed concrete bridges …

Large-Scale Testing To Study The Effects Of Critical Parameters On The Aerodynamic Behavior Of Long Span Bridges, Ramtin Kargarmoakhar

FIU Electronic Theses and Dissertations

Long-span bridges are flexible and therefore are sensitive to wind induced effects. One way to improve the stability of long span bridges against flutter is to use cross-sections that involve twin side-by-side decks. However, this can amplify responses due to vortex induced oscillations.

Wind tunnel testing is a well-established practice to evaluate the stability of bridges against wind loads. In order to study the response of the prototype in laboratory, dynamic similarity requirements should be satisfied. One of the parameters that is normally violated in wind tunnel testing is Reynolds number. In this dissertation, the effects of Reynolds number on …

Experimental And Analytical Methodologies For Predicting Peak Loads On Building Envelopes And Roofing Systems, Maryam Asghari Mooneghi

FIU Electronic Theses and Dissertations

The performance of building envelopes and roofing systems significantly depends on accurate knowledge of wind loads and the response of envelope components under realistic wind conditions. Wind tunnel testing is a well-established practice to determine wind loads on structures. For small structures much larger model scales are needed than for large structures, to maintain modeling accuracy and minimize Reynolds number effects. In these circumstances the ability to obtain a large enough turbulence integral scale is usually compromised by the limited dimensions of the wind tunnel meaning that it is not possible to simulate the low frequency end of the turbulence …

Aerodynamic Testing Of Variable Message Signs, Debbie Meyer

FIU Electronic Theses and Dissertations

The increasing nationwide interest in intelligent transportation systems (ITS) and the need for more efficient transportation have led to the expanding use of variable message sign (VMS) technology. VMS panels are substantially heavier than flat panel aluminum signs and have a larger depth (dimension parallel to the direction of traffic). The additional weight and depth can have a significant effect on the aerodynamic forces and inertial loads transmitted to the support structure. The wind induced drag forces and the response of VMS structures is not well understood. Minimum design requirements for VMS structures are contained in the American Association of …

Development Of A Precast Concrete Supertile Roofing System For The Mitigation Of Extreme Wind Events, Brandon L. Mintz

FIU Electronic Theses and Dissertations

Residential roofs have traditionally formed the weakest part of the structure. The connections of roofs to the walls has lacked a clear load path with the result that the structure is weak at this point, leading to the compromise of the structure. Indeed roofs have multiple points of failure that lead to the weakness of the residential structure as a whole. Even if structural failure does not occur, compromise the roofing membrane can lead to high repair costs and property loss. The failure lies in the complex forming of the roof components as the roof aesthetics are placed to protect …

Comprehending Performance Of Cross-Frames In Skewed Straight Steel I-Girder Bridges, Jawad H. Gull

FIU Electronic Theses and Dissertations

The effects of support in steel bridges can present significant challenges during the construction. The tendency of girders to twist or layovers during the construction can present a particularly challenging problem regarding detailing cross-frames that provide bracing to steel girders. Methods of detailing cross-frames have been investigated in the past to identify some of the issues related to the behavior of straight and skewed steel bridges. However, the absence of a complete and simplified design approach has led to disputes between stakeholders, costly repairs and delays in the construction.

The main objective of this research is to develop a complete …

Development Of Effective Approaches To The Large-Scale Aerodynamic Testing Of Low-Rise Building, Tuan-Chun Fu

FIU Electronic Theses and Dissertations

Low-rise buildings are often subjected to high wind loads during hurricanes that lead to severe damage and cause water intrusion. It is therefore important to estimate accurate wind pressures for design purposes to reduce losses. Wind loads on low-rise buildings can differ significantly depending upon the laboratory in which they were measured. The differences are due in large part to inadequate simulations of the low-frequency content of atmospheric velocity fluctuations in the laboratory and to the small scale of the models used for the measurements. A new partial turbulence simulation methodology was developed for simulating the effect of low-frequency flow …

Reducing Uncertainties In Estimation Of Wind Effects On Tall Buildings Using Aerodynamic Wind Tunnel Tests, Workamaw Paulos Warsido

FIU Electronic Theses and Dissertations

Tall buildings are wind-sensitive structures and could experience high wind-induced effects. Aerodynamic boundary layer wind tunnel testing has been the most commonly used method for estimating wind effects on tall buildings. Design wind effects on tall buildings are estimated through analytical processing of the data obtained from aerodynamic wind tunnel tests. Even though it is widely agreed that the data obtained from wind tunnel testing is fairly reliable the post-test analytical procedures are still argued to have remarkable uncertainties. This research work attempted to assess the uncertainties occurring at different stages of the post-test analytical procedures in detail and suggest …

A Model For Continuous Measurement Of Drilled Shaft Diameter During Construction, Masood Hajali

FIU Electronic Theses and Dissertations

Non-Destructive Testing (NDT) of deep foundations has become an integral part of the industry’s standard manufacturing processes. It is not unusual for the evaluation of the integrity of the concrete to include the measurement of ultrasonic wave speeds. Numerous methods have been proposed that use the propagation speed of ultrasonic waves to check the integrity of concrete for drilled shaft foundations. All such methods evaluate the integrity of the concrete inside the cage and between the access tubes. The integrity of the concrete outside the cage remains to be considered to determine the location of the border between the concrete …