Engineering Commons^™

Bond Behavior Of Advanced Fiber Reinforced Composite-Concrete Joints, Xingxing Zou

Doctoral Dissertations

“Externally bonding advanced composite materials to concrete structures is an effective way to improve their strength, ductility, and durability. The interfacial bond behavior is fundamental to understand the overall structural performance of concrete structures strengthened with advanced composite materials. This study includes a comprehensive investigation of the bond behavior of composite-concrete joints with different fiber reinforced composite types. First, a direct approach to determine the bond-slip relationship for fiber reinforced cementitious matrix (FRCM)-concrete joints based on fiber strain measurements was proposed. Then, an analytical solution to predict the full-range response of FRCM-concrete joints was derived by assuming a trilinear bond-slip …

An Investigation On The Effects Of Cellulose Nanofibrils On The Performance Of Cement Based Composites, Hosain Haddad Kolour

Electronic Theses and Dissertations

Cellulose nanofibrils (CNFs) are hydrophilic biodegradable nanoparticles (typically, less than 0.2 mm in length and 20-50 nm in width) that can be extracted from various plants, trees, and recycled paper stock. Their low density, low toxicity, relatively low cost, high aspect ratio, and high specific surface enable functionalization. In this work, the effects of CNFs on selected properties of cement paste, mortar, and concrete were investigated. For the cement pastes, rheology tests using a simple rheometer showed a reduction in workability as CNF dosage increased. Free shrinkage tests showed an increase in shrinkage at high w/c ratios but a decrease …

Galena Creek Bridge Structural Health Monitoring Instrumentation And Modeling, Leopold Falkensammer

UNLV Theses, Dissertations, Professional Papers, and Capstones

Structural health monitoring (SHM) of an instrumented structure provides numerous benefits when assessing the long-term condition of the structure against degradation, or the short-term condition after an extreme event, such as an earthquake. The Nevada Department of Transportation (NDOT) has an interest in expanding the use of SHM for such assessments. Accordingly, the objective of the current study is to develop and implement a permanent SHM system for the Galena Creek Bridge, the largest concrete cathedral arch bridge in the world, to monitor its response to routine traffic and seismic activity. Completed in 2012, the bridge connects Reno and Carson …

Evaluation Of Concrete Deck Curing Regimens Using Capillary Pressure Sensing System, Samuel Spann

Graduate Theses and Dissertations

Early-age plastic shrinkage cracking is a common problem with the construction of concrete bridge decks due to the high surface area-to-volume ratio and exposure to potentially detrimental environmental effects. Curing regimens are utilized to mitigate cracking risk during the plastic stage of the concrete; the curing regimens evaluated for this study were wet burlap-polyethylene sheeting, two acrylic curing compounds, and one lithium compound. Capillary pressure in the water filled pores has been shown to correlate to the plastic shrinkage cracking risk of concrete. A new portable system has been developed to measure the capillary pressure that could potentially be used …

The Development Of A Novel Experiment On Confined, Flattened Brazilian Disks To Correlate Damage And Permeability In Brittle Geo-Materials, Samuel H. Boyce

Civil Engineering ETDs

This research develops a novel experiment using flattened Brazilian disks under confining pressure with concurrent permeability measurements and acoustic emission monitoring. The purpose of this work is to correlate damage and permeability in brittle geo-materials. Two series of tests are performed on concrete and one series on tuff, under a range of confining stresses between 2.76 and 13.79 MPa. Tests were continued beyond peak stress conditions, capturing data in the post-peak region. The acoustic emission data (cumulative energy and counts) are used to identify damage thresholds and track the progression of microscopic damage. This quantified damage is then correlated to …

The Influence Of Citric Acid On Setting Time And Temperature Behavior Of Calcium Sulfoaluminate-Belite Cement, Edgar Soriano

Civil Engineering Undergraduate Honors Theses

Today the need to opt for alternative cementitious materials is growing due to environmental reasons and construction time frames that portland cement cannot always satisfy. Calcium Sulfoaluminate (CSA) cements are a strong candidate to supplement or replace portland cement in the construction field for certain applications. In the United States, CSA cement has been limited mostly to pavement repairs because of its rapid initial setting time. The chemical compound responsible for this phenomenon is the alumina. This compound and sulfate are present in larger proportions compared to portland cement. The purpose of this research is to study how the use …

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 …

Analysis Of Standardized Concrete Mixes, Riley Graybeal

Williams Honors College, Honors Research Projects

Concrete is one of the most common materials used in construction. It is mass produced throughout the country, with numerous different designs for concrete mixes. A common practice among concrete manufacturers is to use a standardized concrete mix design. These standardized mix designs are pre-tested and are not usually altered frequently. The hypothesis of this research project is that manufacturers do not constantly investigate new ways to save on their mixes, and simply use the same standardized mix designs.

In this research, investigations into what alterations may reduce the cost of standardized mixes began with a baseline mix design provided …

Incorporation Of Contaminated Sediment Into Environmentally Safe Concrete, Andrew Needs

Williams Honors College, Honors Research Projects

The research performed through this project provided some interesting results on how the different properties of the contaminated sediment can impact the strength of the new concrete.

Average three, seven, and fourteen-day strengths increased when comparing to the baseline mix developed for the experiment. Increases in strengths were notices in the ten and twenty-five percent soil replacement mixes. The largest increase was approximately thirty-three percent greater than the baseline average.

The results from the forty percent replacement test showed a significant decrease in strengths when comparing against the baseline mix. A loss of about thirty percent was observed between the …

On The Development Of 8,000 Psi Geopolymer Mortar For Practical Use In Field Applications, Remington Gabriel Reed

Graduate Theses and Dissertations

Although there are several perceived benefits from the use of geopolymer binder as an alternative to ordinary portland cement in concrete materials, it is not widely used in field applications. Geopolymer materials have no set guidelines for mixture design and often require heat curing to facilitate strength gain. Additionally, many geopolymers are created using carefully controlled and high quality materials and activator chemicals. These factors greatly affect the practicality of the material. The goal of this research was to create a geopolymer material capable of achieving high compressive strengths at 28 days without heat curing, and using only readily available …

Effect Of Cement Content On Concrete Performance, Caleb Joshua Lebow

Graduate Theses and Dissertations

Of all the traditional concrete materials, portland cement has the greatest impact on mixture cost and the environment. Cement is in many ways the glue holding concrete together (Weiss, 1999), and as such, it plays a major role in fresh and hardened concrete properties. Without the proper range of cement in the mixture, low strength development or excessive shrinkage may occur leading to premature deterioration. The Arkansas Department of Transportation (ARDOT) recognizes two types of concrete for use in bridge construction, Class S and Class S(AE). This paper focuses on the findings from testing of Class S(AE) concrete, short for …

Modeling And Simulation Of Damage In The Brazilian Indirect Tension Test Using The Finite-Discrete Element Method, Jeremiah C. Leyba

Civil Engineering ETDs

The Brazilian indirect tension test is used to investigate possible correlations between progressive damage and associated permeability changes. The test offers ease of replicability with a damage behavior known to lead to fracture openings as a tool for interpreting the indirect tensile strength of concrete and rocks. This behavior can lend insight into the nature of tensile damage and fracture progression in association with changes in permeability. The nature of these brittle materials is known to exhibit rapid failures in the Brazilian indirect tension test and require a method to retard the progression of damage for the possibility of acquiring …

Understanding Asphalt Concrete Aging Using Nanoindentation, Hasan M. Faisal

Civil Engineering ETDs

Asphalt concrete (AC) is created by mixing liquid asphalt binder with solid aggregates. When asphalt binder is mixed with aggregates, it creates a thin film (about 7-16 microns thick) around the aggregate surface. Fine aggregate (smaller than 0.075 mm size) get entrapped within the binder film or mixed with the binder, and create a phase called mastic. Both asphalt film and mastic play significant roles in aging of asphalt pavement. To this day, tests were performed mainly on the bulk liquid asphalt, but not on the film or mastic. In this study, for the first time, nanoindentation tests were done …

Investigating Early Age Behavior Of Portland Cement Concrete In Arid Regions, Evan Wolf

Open Access Theses & Dissertations

The early-age behavior and properties of portland cement concrete change rapidly over time as a result of the hydration process. Comprised of a series of chemical reactions, this process accelerates nonlinearly with the curing temperature. Gaining knowledge and understanding of the phases of the hydration process (i.e., dormant, setting, and hardening) plays an important role in the timely opening of roads, resuming of construction, and achieving long-term performance. Standard tests such as ASTM C403 arbitrarily define the time of initial and final setting of concrete. Despite decades of studies concerning setting times, actual predictions still span hours, while the quality …

Numerical And Experimental Analysis Of Local Buckling Of Axially Loaded Steel Tubes Confined By Concrete And Frp, Nicholas Colbert

Masters Theses

“The hollow core Fiber-Reinforced-Polymer (FRP) concrete circular-steel (HC-FCS) column consists of an outer circular fiber reinforced polymer (FRP) tube, an inner thin-walled circular steel tube concentrically aligned, and a concrete shell between them. Research has been performed on the performance of the member as a whole, but to date, there has been no investigation into the behavior of the steel tube confined in the column. 17 small-scale columns were tested under axisymmetric axial compressions applied directly to the steel tube under displacement control. The conducted parametric study examined the effects of diameter-to-thickness (D/t) ratio, concrete unconfined compressive strength, FRP thickness, …

Nondestructive Evaluation Of Corrosion Damage In Reinforced Concrete Aged Slab Specimen, Rawya Abdulsattar Abduljabbar

Theses and Dissertations

The deterioration of concrete bridge decks presents a maintenance challenge for most transportation agencies and bridge owners. This problem increases during the freeze-thaw cycle. De-icing salts can accelerate the deterioration process. Corrosion of steel reinforcement in reinforced concrete structures is considered a dominant factor causing premature deterioration, especially those structures located in a coastal environment. The resulting corrosion product produced has several times the volume of steel, resulting in cracking of the concrete cover if the corrosion is significant. In this study, a bridge deck specimen was subjected to an artificial environment to accelerate the corrosion process. Prior to this …

Testing And Modeling Of The Thixotropic Behavior Of Cementitious Materials., Bashir Hasanzadeh

Electronic Theses and Dissertations

During construction, concrete goes under various operations. It is normally transported to the job site, be placed and consolidated in the formwork, etc. The easiness and quality of these operations are very much related to the intrinsic rheological properties of concrete. Therefore, a good understanding of rheological behavior of concrete under various conditions are needed. Thixotropy is an important part of rheology. The thixotropic behaviors of concrete can be good representatives of its flow behaviors on the job site. For example, the breakdown aspect of thixotropy can help to explain how its flow behavior can impact concrete pumping and its …

Development Of High Early-Strength Concrete For Accelerated Bridge Construction Closure Pour Connections, Stephanie Castine

Masters Theses

Accelerated bridge construction (ABC) has become a popular alternative to using traditional construction techniques in new bridge construction and existing bridge deck replacement because of the reduction of time spent in field activities. A key feature of bridges built using ABC techniques is the extensive use of prefabricated components. Prefabricated components are joined in the field using small volume closure pours involving high performance materials (steel and concrete) to ensure adequate transfer of forces between components. To date, the materials developed for closure pours have been based on proprietary components, so a need has arisen for development of mixes that …

Shrinkage Cracking In Concrete Tilt-Up Construction, Stewart Hooks, Jack Robinson

Architectural Engineering

The purpose of this project is to investigate a particular, undesirable cracking pattern in concrete tilt-up panels that, until now, did not have a known definite cause. The cause of this cracking pattern is hypothesized to be due to shrinkage restraint of the concrete panels. The cracking under investigation occurs at the bottom corners of the Tilt-Up panels, suggesting that the base of the panel is restrained from shrinkage. This project models various components of Tilt-Up Construction that have potential for restraining the panels from shrinking. This project consists of the following main components.

The first aspect of this project …

Assessments Of Concrete Internal Damage Caused By Freeze-Thaw Cycles And Mechanical Loading, Zeqian Li

Theses and Dissertations

Concrete in bridge decks in Northern States, such as Wisconsin, is subjected to both freeze-thaw cycles and mechanical stresses. Standard testing methods are available to evaluate the deterioration of concrete, including ASTM C215 (Dynamic Modulus test), ASTM C1202 (Rapid Chloride Ion Penetrability test), and ASTM WK37880 (ESR test) are available. In addition, ASTM C642 (water absorption test) helps quantification of permeable voids in concrete. These tests have been used to evaluate undamaged concrete or concrete samples after freeze-thaw cycles.

The concrete samples in this study have been subjected to compressive stresses (0.4f_c^') and freeze-thaw cycles (100 to 300 cycles) to …

Electrochemical Methods To Characterize Drilled Shaft Deficiencies, Sarah Jo Mobley

USF Tampa Graduate Theses and Dissertations

In recent years drilled shafts have become the preferred foundation method for marine bridges. Typically, the drilled shaft is selected over traditional driven piles due to soil strata encountered, construction economy, increased lateral stiffness requirements, and/or vibration control considerations. The most critical component in drilled shaft construction is borehole stabilization. Wall sloughing or groundwater inclusion can have devastating effects on the strength of the finished shaft however recent research has shown that the materials, more specifically the slurry, used to accomplish stabilization may be having a negative impact on the durability of the finished product. This thesis investigates the durability …

Compressive Strength Relative To Sustainable Materials In Concrete, Brad Harvey

Williams Honors College, Honors Research Projects

The objective of this study is to determine how integrating abundant waste materials into concrete affects its compressive strength. This research will be used to benefit the construction industry by replacing a portion of a conventional concrete mix (cement, stone, sand, and water) with more sustainable materials. In order to create a more sustainable concrete mixture, the following mix design and methodology was followed.

The initial step was to create an updatable MS Excel spreadsheet to aid in the mix development (the spreadsheet is shown in Appendix A). These sheets allowed for easy transitions from one mix to another by …

Chemical Modification Of Crumb Rubber To Increase Its Bonding With Concrete, Mary T. Mccannon, Kendall J. Sweitzer

Williams Honors College, Honors Research Projects

The hydrophilicity of crumb rubber was increased with wet chemical modification and added to concrete to increase its adhesion with concrete, consequently the compressive strength relative to that of concrete with untreated rubber. Other modification methods were tested on crumb rubber and rubber sheets to yield an increase in hydrophilicity. Certain tests were less reliable for powder testing or tedious and time consuming and concrete materials and rubber may not be homogeneous.

For wet chemical modification, several approaches were attempted. First, crumb rubber was soaked in 5% sodium hydroxide, 5% potassium permanganate and saturated sodium bisulfite, tested for hydrophilicity using …

Reflectivity Of Light Emitting Diodes (Led) And Incandescent Lights On Concrete And Asphalt Pavements., Jeremy Elliott Rice

Electronic Theses and Dissertations

The purpose of this study is to investigate the reflectivity of light on concrete and asphalt pavement systems. In 1983, the Illuminating Engineering Society (IES) published the first recommended practice (RP-8) for the design of roadway and parking lot lighting. This design method implemented empirically tested factors which were defined as the “reduced luminance coefficients” or the R-Tables. The R-Tables are essential for proper design of light pole installation dimensions, required power, and the distribution of light. The originally tested pavements are not necessarily representative of modern pavement materials used today. Moreover, recent Light Emitting Diodes (LED) are a relatively …

Feasibility Study Of Using Recyclable Polyethylene (Pet) Materials As Coarse Aggregate For Concrete Mixtures, Philip M. Angelo

Construction Management

The feasibility of using recyclable household plastics, specifically those made of polyethylene, commonly used in water and soda bottles, as a replacement for concrete coarse aggregate, was assessed. A method was developed for cutting polyethylene materials into fibrous strips. These strips were then used as a replacement for the rock coarse aggregate in batches of concrete. Standard 6” x 12” test cylinders were made using the concrete mixture and subject to destructive compressive testing in order to yield the compressive strength of the concrete mix 7, 14, 21, and 28 days after pouring. Three mixtures were tested, one control with …

Seismic Design Of A Prestressed Concrete Bridge, Alperen Ozel

University of New Orleans Theses and Dissertations

Latest advancements in software have become an indispensable tool in structural analysis. The main goal of this thesis is to examine dynamic responses of bridges in seismic activity with the help of such tool as CSi Bridge. Therefore, throughout this study, a prestressed concrete bridge model will be thoroughly designed. In the first section, the required materials and structural components will be introduced. The following section will cover calculations required for modeling. The actual modeling of the structure will be carried out in Section 3. In Section 4, the set of required analysis for seismic design such as modal, pushover …

Impact Of Extreme Summer Temperatures On Bridge Structures, Ryan Hagedorn

Graduate Theses and Dissertations

Climate change and its effect on weather in the United States is a well-documented phenomenon. In particular, extreme heat waves have become more intense, more frequent, and longer lasting, especially in the southern United States. As with much of America’s transportation infrastructure, prestressed concrete bridge girders experience the effects of these heat waves. Uneven heating of optimized bridge girder sections results in large non-linear temperature gradients. In this study, temperature was monitored in three different AASHTO I-girders to determine the vertical and transverse temperature gradients in a pre-deck placement condition. It was determined that the current design standard, which uses …

Quantification And Characterization Of Fracture Resistance In Asphalt Concrete Based On R-Curve Method, Shu Yang

Graduate Theses and Dissertations

The application of fracture energy is widely applied in the evaluation of cracking in the laboratory for asphalt concrete. However, this single number does not provide information on the characterization of the initiation and propagation of cracks. The Resistance Curve method, or R-Curve, is widely applied in characterizing various materials including, but not limited to, metal, polymer, rock, and composite. This research R-Curve method introduces asphalt concrete through a stepwise approach. First, in chapter one, there is a literature review of the history of fracture mechanics, fracture research in asphalt concrete, and an examination of the role of R-Curve application …

Normal-Strength And High-Strength Concrete Columns Under Cyclic Axial Load And Biaxial Moment, Mehdi Zarei

Dissertations

The technique of using Carbon Fiber Reinforced Polymer (CFRP) materials to repair and strengthen various concrete members has become popular in the structural retrofitting field as an effective way to enhance the strength and ductility of concrete members due to its superior mechanical properties. In this study a method was introduced to study the behavior of concrete columns with and without CFRP jackets under constant axial load and variable lateral load. The lateral load was applied monotonically and cyclically. To predict the behavior of concrete columns under monotonic and cyclic compressive loadings, a computer code was developed to produce the …

Investigation Into Mechanisms And Mitigation Of Alkali-Silica Reaction In Sustainable Portland Cement Concrete Containing Recycled Glass Materials, Kaveh Afshinnia

All Dissertations

A significant portion of recycled glass from municipal waste streams is not found to be suitable for reuse as cullet in the production of new glass containers, and as a result it is disposed in landfills. One of the appropriate ways to reduce the disposal of waste glass in landfills is by using it in portland cement concrete as an aggregate material and/or supplementary cementitious material to replace portion of portland cement. The high silica content of the soda glass (approximately 70%) can potentially behave as a pozzolanic material when finely ground, which may enhance the mechanical and durability properties …