Engineering Commons^™

Development Of Vacuum Assisted Resin Transfer Molding (Vartm) Method For The Repair And Strengthening Of Concrete Structures, Luis Ramos

All ETDs from UAB

Resin infusion, a method of fabricating fiber reinforced polymer (FRP), has been shown to produce a stronger FRP of more consistent quality than other methods. It is a preferred method of fabrication in industries like automotive, aerospace, and boat build-ing. In infrastructure, however, FRP is commonly applied by the hand layup method. Hand layup is known to produce FRP of questionable quality. Vacuum Assisted Resin Transfer Molding (VARTM), a form of resin infusion, can be used to apply externally bonded FRP to infrastructure to increase structural ca-pacity. Based on experience and knowledge in other industries, VARTM is expected to produce …

Assessing Corrosion Damage In Post -Tensioned Concrete Structures Using Acoustic Emission & A Preliminary Investigation Of Biopolymer Doped Cement Mortar For Use In Structural Restoration, Aditya Appalla

Theses and Dissertations

A sizeable portion of the civil infrastructure is made from concrete. An estimate shows that about 7 billion cubic meters of concrete is made annually worldwide. With the deterioration of the infrastructure due to aging or external factors, significant monetary and technological investment is needed for condition evaluation, maintenance and repair. Two areas that account for a considerable portion of this investment are condition evaluation for maintenance of corroded concrete structures and mortar patching for repair and rehabilitation.

The primary method of evaluation of a structure is by visual inspection. But this method is limited as some crucial areas in …

Kelvin Probe Electrode For Contactless Potential Measurement On Concrete-Properties And Applications, Michael Thomas Walsh

USF Tampa Graduate Theses and Dissertations

The practical feasibility of using a Kelvin Probe as a novel reference electrode in the measurement of both potential and polarization pulse response of reinforcing steel in concrete is demonstrated. Potential values measured using a KP reflect greater stability and repeatability than can typically be attained with conventional reference electrodes. Duplicate reinforced concrete beam test specimens with well-differentiated centrally corroding rebar segments were analyzed using both the Kelvin Probe (KP) and a conventional Saturated Calomel Electrode (SCE). Potential profile maps were developed using potential values recorded under static conditions with both the SCE and the KP. Nominal polarization resistance was …

Conductive Concrete For Electromagnetic Shielding – Methods For Development And Evaluation, Aaron P. Krause

Department of Computer Electronics and Engineering: Dissertations, Theses, and Student Research

This research investigates the development and evaluation innovative methods for the use of conductive concrete as an electromagnetic shield. New testing methods are developed to determine the best conductive components to use in the design of a concrete mixture for shielding that shows the best promise. The conductive concrete mixture has the potential to provide electromagnetic shielding that is cost-effective in terms of construction, operation, and maintenance compared to conventional approaches. Two testing methods, Small Sample Testing and Large Slab Testing, are developed based on standardized testing methods that have been modified for the testing of conductive concrete mixtures. As …

Pullout Strength Of Epoxy Anchors Installed Underwater, Jeffrey Lee Blanchette

Master's Theses

This work presents the development of a test program and the results from the final round of testing to better understand the effect a submerged anchor installation has on the pullout strength of epoxy anchors. Two different epoxies were tested at embedment depths of two, four, and six bar diameters. These tests utilized three distinct installation procedures under dry and submerged conditions. The testing program occurred over five phases, with the final round used in analysis consisting of 24 anchor pullout tests. These tests showed that the presence of water did not have an effect on the epoxy bond when …

Study On Corrosion Activity Of Carbon Steel In Concrete Simulated Pore Solution Under Static Tensile And Compressive Stresses, Yujie Zhang

All Theses

Reinforced concrete is a structure material made up of concrete with relatively lower tensile strength containing reinforcements with higher tensile strength and better ductility, which are embedded into fresh concrete to resist tensile stress in certain regions of concrete. Steel reinforced concrete is most widely used around the world in civil engineering structures, water conservancy and highway construction due to its durability strength and reasonable cost.
However, reinforced concrete structures such as bridges and parking lots slabs inevitably experience variable loads and constant degradation from the aggressive environments, such as marine and deicing salts. Therefore, it is imperative to study …

Durability Of Reinforced Concrete Incorporating Crushed Waste Brick As Coarse Aggregate, Matthew Adamson

All Theses

Using crushed bricks as aggregates in concrete is of particular interest to preserve natural aggregate sources as well as to reduce waste, as it has been estimated that 10% to 30% of all waste in landfills in the united States comes from construction and demolition wastes. By recycling some of these wastes, the sustainability of a project can be improved. However, it is important concrete incorporating these wastes is as durable or more durable then conventional concrete, or will it have a shorter service life. Durability of concrete is its ability to resist deterioration from its external environment such as …

Incorporation Of Life Cycle Models In Determining Optimal Wind Energy Infrastructural Provision, Brendan Cleary, Aidan Duffy, Alan O'Connor

Conference papers

The deployment of wind energy has grown rapidly over the last two decades with an average annual growth rate of more than 26% since 1990. During this period the development and innovation of wind turbines has resulted in continual growth in wind turbine size with output ranges of 10-15MW likely to be deployed by 2020. This increased output has a knock-on effect on the growth of rotor diameters and tower heights. Wind turbine towers are required to become taller, stronger and stiffer in order to carry the increased weight and associated structural loading. Consequently, the dimensions of the tower cross-sections …

Behavior Of Segmental Precast Posttensioned Bridge Piers Under Lateral Loads, Haitham Dawood, Mohamed Elgawady, Joshua Hewes

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Abstract a segmental precast posttensioned (SPPT) bridge pier is an economic recentering structural system. Understanding the seismic behavior of a SPPT system is an important step toward its application in high seismic zones. This paper presents a detailed three-dimensional finite-element (FE) model that was developed using the ABAQUS platform. a brief description and discussion of cyclic tests on eight large-scale SPPT piers is also presented. Four of the piers were constructed and tested to a predefined degree of damage. Then, these piers were retrofitted and retested. the FE models developed and presented in this paper predicted the backbone curves of …

High-Volume Fly Ash Concrete For Sustainable Construction, Jeffery S. Volz

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

With worldwide production of fly ash approaching 800 million tons annually, increasing the amount of fly ash used in concrete will remove more material from the solid waste stream and reduce the amount ending up in landfills. However, most specifications limit the amount of cement replacement with fly ash to less than 25 or 30%. Concrete with fly ash replacement levels of at least 50% - referred to as high-volume fly ash (HVFA) concrete - offers a potential green solution. the following study investigated the structural performance of HVFA concrete compared to conventional Portland-cement concrete. Specifically, the research examined both …

Effects Of Alternate Cementitious Materials On Compressive Strength And Environmental Impacts Of Cement Mix Designs., Mitchell R. Bush

Materials Engineering

Specific proportions of Portland cement, fly ash, and blast furnace slag cement mixtures where chosen by a ternary phase diagram to be investigated. By experimental testing and company data history fly ash was limited to not exceed 30% and contribution of Portland cement must be over 50%. Ten chosen mix designs were batched by following ASTM C305-94 and cured for twenty-eight and forty-two days, the extended cure length allows the reaction of pozzolanic material with calcium hydroxide to complete. Compressive strength testing at forty-two days yielded low strength for mix designs with 20% or less Portland cement compared to our …

Implementation, Design, And Cost Analysis Of A Concrete Washout System, Omar Adina

BioResource and Agricultural Engineering

With the increase of environmental pollution in today’s world, many strategies and regulations are being enforced. These enforcements come from the state and federal governments, but public awareness is often overlooked. Stormwater regulations here in California have dramatically changed over the last decade, as the topic is investigated more often.

This senior project encompassed the design prototype and cost analysis of a permanent concrete washout station for the BioResource and Agricultural Engineering Department at California Polytechnic State University, San Luis Obispo. The design parameters given were to construct a steel bin for the excess concrete to be dumped into during …

Concrete Design For Traffic Application, Marc Shields

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Inductive charging of electronic devices is a newer technology that is capable of transferring electrical power without physical contact through wiring. Research is currently being done to find and improve ways to implement this technology on electric cars. If this type of technology pas implemented on a large scale throughout much of the country, electrical or hybrid cars could travel across counties and states without depleting their batteries.

The current problem with electric cars is that they have a limited range of travel. Even with larger batteries with much more capacitance, the range of pure electric cars usually does not …

Structural Performance Of Reinforced Concrete Flat Plat Buildings Subjected To Fire, Sara Jean George

UNLV Theses, Dissertations, Professional Papers, and Capstones

Reinforced concrete structures are typically considered to have inherent resistance to fire. However, several concrete structures around the world have experienced partial or total collapse under fire. Reinforced concrete flat-plate is a type of structural system widely used for office and residential buildings. Flat plate construction is prone to punching shear failure at slab-column connections which may lead to a catastrophic progressive collapse. The slabs of flat-plates generally have very thin concrete cover leaving steel reinforcement more sensitive to thermal loads. Little is known in the engineering community about the structural performance of flat-plate structures subjected to fire. Through a …

Investigating The Use Of Pozzolans In Portland Cement Concrete And Inorganic Polymer Mortar, Omar Abdelmalek Saleh

UNLV Theses, Dissertations, Professional Papers, and Capstones

The use of pozzolans offers promising signs for a change in the cement industry. Pozzolan in its natural and artificial forms can be used to improve cement properties or to synthesize new cement. This study investigates the use of pozzolans in portland cement concrete and inorganic polymer mortar (geopolymer mortar).

This thesis is divided into two phases. Phase 1 investigates the use of natural pozzolan as a partial replacement of portland cement in concrete. In this phase two types of class N pozzolan are used separately to develop concrete mixtures contain different percentages of class N pozzolan. Fresh concrete properties …

Recycling Concrete For Sustainable Construction, Joseph M. Dardis

ETD Archive

The demolition of concrete structures has made concrete debris the largest portion of the waste stream in the U.S. With landfills becoming scarcer, the need to recycle demolition debris is becoming increasingly relevant. An effective way to recycle this material is to produce recycled concrete aggregate (RCA) and use this material in the reconstruction of buildings and roads. Producing and re-using RCA will reduce landfill waste and save energy by minimizing the production and transport of natural aggregates. The focus of this thesis is to quantify how much energy can be saved by producing and re-using RCA instead of landfilling …

Feasibility Of Expanding The Use Of Steel Slag As A Concrete Pavement Aggregate, Brad A. Fronek

ETD Archive

Sustainability has become an important aspect of developed countries throughout the world. Sustainability is the ability to use byproducts and or waste materials from industry and recycle these materials in such a way that the application of the materials provides a beneficial use in the manufacturing or construction sector. As the United States and the rest of the world continue to grow, so too does the demand on the limited natural resources throughout the world. It is this demand on the resources that has brought the idea of sustainability to the forefront of research and design.The transportation industry continues to …

Analysis Of Uncontrolled Concrete Bridge Parapet Cracking, Jeffrey D. Bazzo

ETD Archive

The Ohio Transportation has recently identified the problem of wide-spread premature cracking of concrete bridge parapets throughout its District 12 region (Northeast Ohio). Many of the bridge decks that contain these prematurely cracked parapets are of relatively recent construction. In severe cases, replacement of the parapet may be required before replacement of the bridge deck itself. This incurs a sunk cost upon the bridge owner, as the parapets will again be replaced during the regularly scheduled replacement of the bridge deck. In a recent instance, the replacement of a cracked parapet (without replacing the deck) cost District 12 approximately $140,000. …

Introducing Fly Ash Into Lsi's Recipe, Andrew Mathias Beckrich

All Graduate Theses, Dissertations, and Other Capstone Projects

There has been published data that states that concrete producers can use Fly Ash as an alternative to Portland cement and still generate similar or better strength properties. By applying these principles to our industry and products, what new processes will need to be put in place and followed? What is the correct combination/portion of Fly Ash that will produce similar and better results as well as the adjusted new recipes? What type of cost is associated with the introduction of this new ingredient? Lastly, how does this affect the quality and reputation of the product?

Effects Of High Volume Fly Ash And Powder Activators On Plastic And Hardened Concrete Properties, Drew Alexander Davis

Masters Theses

This study was performed to examine the effects of high volumes of Class C fly ash modified by powder activators upon the plastic and hardened properties of concrete. In a companion study, five Missouri area cements and five Class C fly ashes were examined for incompatibilities, with the most and least reactive combinations being scaled up to full scale concrete testing. Two baseline concrete mixtures were examined, the only difference in mixtures being the sources of portland cement and fly ash. Fly ash replacement was examined at 50% and 70% replacement (by total cementitious mass). Three powder activators were used …

The Quantification Of The Fly Ash Adsorption Capacity For The Purpose Of Characterization And Use In Concrete, Zeyad Tareq Ahmed

Dissertations, Master's Theses and Master's Reports - Open

Fly ash has been shown to be an effective replacement for portland cement in concrete mixtures. However, many fly ash materials contain unburned carbon from the combustion process. Unburned carbon in fly ash adsorbs air entraining admixtures (AEAs) reducing their effectiveness in providing a specified air void system in concrete materials. Measurement tools and methods for characterization of the adsorption properties of fly ash materials are necessary for beneficial use of fly ash materials in concrete. In this research, two methods were developed to measure and quantify the adsorption capacity AEAs on fly ash materials. The first method is the …

Strengthening Of Reinforced Concrete Beams Pre-Damaged In Shear, Yousef Mohammed Bachar Chekfeh

Theses

Repair and strengthening of existing reinforced concrete (RC) structures has increased drastically in recent years. Shear reinforcement in RC beams is typically of a small bar diameter, and hence any shear-damage would result in a severe safety hazard and a catastrophic mode of failure especially under extreme loading events. The present work was initiated to the effectiveness of different composite strengthening systems; namely externally bonded carbon fiber reinforced polymer (EB-CFRP), and near surface mounted glass fiber reinforced polymer (NSM-GFRP) to prolong the functional service life of RC beams pre-damaged in shear. It comprised experimental testing and analytical investigation.

The experimental …

Sensitivity Analysis Of Time/Depth Dependent Chloride Diffusion Coefficient In Concrete, Yung-Ming Sun, Ta-Peng Chang, Ming-Te Liang

Journal of Marine Science and Technology–Taiwan

This paper presents the results for a sensitivity analysis of the time/depth dependent chloride diffusion model in concrete using differential analysis techniques. Four governing prameters of the model are taken to determine the sensitivity of the chloride diffusion coefficient: the time of exposure, inspecting depth, surface chloride concentration, and chloride concetration at the inspecting point. The results of this sensitivity analysis are discussed in detail, including variations in the diffusion coefficient according to the four parameters and the implications for durability design of concrete structures.

Development Of A Structured Concrete Thermocline Thermal Energy Storage System, Bradley M. Brown

Graduate Theses and Dissertations

The past couple of decades have shown a concern when considering the way the world obtains its power. The focus has been switching from fossil fuels that have been used for hundreds of years to renewable energy sources, such as the sun. Solar energy is readily and infinitely available for harnessing. One problem with solar energy, though, is its inability to be used during the night time and during cloud covered weather. A solution to this problem is the use of energy storage mechanisms. For solar plants that use solar thermal energy (concentrating solar power plants), thermal energy storage (TES) …

Accelerated Construction For Pedestrian Bridges: A Comparison Between High Strength Concrete (Hsc) And High-Strength Self Consolidating Concrete (Hs-Scc), John J. Myers, Kurt Bloch

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

High-strength concrete (HSC) and glass fiber reinforced polymer (GFRP) bars are materials utilized in bridge construction to lower cost, reduce construction time, and increase service life of bridge structures. Recently, high-strength self-consolidating concrete (HS-SCC), a highly flowable concrete that does not require vibration, has been developed as a viable alternative to HSC for use in situations with congested steel or a need for rapid construction. Coupling HS-SCC with GFRP bars could create durable structures built rapidly. Several performance related issues remain to be investigated such as the behavior of prestress loss, shear, creep, shrinkage, thermal gradients, mechanical property development, time …

Retrofit Solutions For Sealed Pervious Concrete Pavements, Gregory Bunting

All Theses

The goal of this research was to design, implement, and evaluate several retrofit solutions for sealed pervious concrete. Properly functioning pervious concrete pavements allow water to drain through the structure, eliminating the need for traditional drainage infrastructure. A recent study of South Carolina porous pavements (Putman 2010) revealed that some pervious concrete pavements are not properly draining, either because of sealing at the surface. Sealed pavements are generally a result of construction processes, and sealed pavements cannot be fixed with sediment removal techniques such as vacuuming and pressure washing. This study investigates a technique to increase infiltration of sealed pervious …

Investigation Into The Role Of Airfield Pavement Deicer In Concrete Pavement Deterioration, David Wingard

All Dissertations

Premature deterioration of concrete due to materials-related distresses has been observed with increased frequency in airfield pavements across the United States in the past two decades. The use of a new breed of deicing chemicals based on alkali-acetates and alkali-formates, starting in the early 1990s, has been suspected to be one of the significant reasons for the increase in the observed deterioration. Previous laboratory-based studies have found that the early-age deterioration in concrete is associated with exposure to deicers causing acceleration of the Alkali Silica Reaction (ASR) deterioration mechanism and consequent failure. However, no systematic forensic studies on the impact …

Recycling Waste Latex Paint In Overlays, Rigid Pavements, And Pervious Concrete, Oscar Inez Quiroz

UNLV Theses, Dissertations, Professional Papers, and Capstones

With over 16 million gallons of latex paint (WLP) being disposed every year it is the largest by volume, liquid hazardous waste in the United States. WLP is difficult to recycle and hazardous to the environment due to the volatile organic compounds it contains. Several methods exist for disposing WLP including paint swaps, combustion, drying and discarding in a landfill, and by placing pigments in cement. Many communities are moving to dispose WLP by drying and placing in a landfill due to the reduced cost. However, this is the least preferred technique for the environment because it creates a need …

Piedras Blancas Light Station Vista Point Improvement Plan, Larissa Heeren, Reuben Juster, Annamarie Usher, John Rossi, Nick Mitchell

Mechanical Engineering

Piedras Blancas Light station Improvement Involved the design of two separate parking lot/vista point plans as well as the creation of a concrete Iron Ranger located near the gift shop on site.

Gis Based Pavement Maintenance: A Systematic Approach, Robert J. Kmetz

Purdue Polytechnic Directed Projects

Abstract

According to 2008 Federal Highway Administration (FHWA) statistics, there are 2,734,102 miles of paved public roads in the United Sates, with an additional 1,324,245 miles of unpaved public roads.  Road conditions deteriorate with time as the result of weather effects, deicing salts, and vehicle loads.  The most common pavement distress includes cracking, rutting, and potholes.  These pavement defects must be repaired to restore the pavement to a satisfactory service level for road users. According to the FHWA, in 2006 approximately $54.2 billion dollars was spent on maintenance and expansion, just on U.S. highways alone.

Routine maintenance is a cost …