Engineering Commons^™

Building A Handicap Accessible Entrance And Gabion Wall, David C. Marter

Construction Management

As people age, their bodies naturally deteriorate and often times people are confined to wheelchairs in order to get around. Uneven and unstable ground is a large obstacle for people who live confined to a wheelchair. This project was derived and designed in order to help a family with multiple family members bound to wheelchairs to allow them an easier point of access into the home. The project itself consists of the construction of a concrete walkway and a gabion wall to provide some additional aesthetics. The concrete pathway ranges from the driveway to a paver pathway that curves around …

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 …

Feasibility Of Hybrid Thermoplastic Composite-Concrete Load Bearing System, Camerin M. Seigars

Electronic Theses and Dissertations

Thermoplastic composites have many advantages over thermoset composites such as being recyclable, rapidly manufacturable, and more impact resistant. The goal of this thesis is to assess the feasibility of using thermoplastic composites in structural applications through literature review, mechanical testing, design of a load-bearing hybrid composite-concrete structures, and the implementation of thermoplastic composites for tensile reinforcement of concrete. The study had four objectives covering the stated goal.

1. Conduct a literature review to direct thermoplastic material selection
2. Characterize thermoplastic material mechanical properties using standardized mechanical testing
3. Design a hybrid composite-reinforced concrete beam, and
4. Develop thermoplastic shear connectors to develop composite action …

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 …

Alternate Reinforcement For Structural Concrete, Barrett Lowe

Construction Management

Concrete has been utilized on construction projects for thousands of years, ranging from the Pyramids to the foundation your home is built on. Innovated upon, concrete and its properties have changed over the years, one of the greatest being the discovery of tensile reinforcement. Rebar, commonly known as reinforcing steel or reinforcement bars, have been used in the construction industry for decades. Ranging in size and application, rebar’s unmatched tensile strength and anti-corrosive properties make it the champion of reinforcing structural concrete. Though the advancement in technology has created a new era where other materials may take its place. Attempting …

The Production Of Pyrolytic Biochar For Addition In Value-Added Composite Material, Douglas Matthew Cuthbertson

Electronic Thesis and Dissertation Repository

Pyrolytic biochar has recently gained attention for its potential value as a carbon sequestering by-product that can be used in industrial applications. While biochar is typically targeted for soil amendment applications, higher value applications such as addition in consumer products and building materials needs to be investigated.

In this study, biochar is produced from three different Canadian feedstocks using three different pyrolysis methods. The biochar is characterized to determine the effects that feedstock selection and pyrolysis conditions has on biochar properties. The biochar is also incorporated into concrete at varying concentrations to create a lightweight and sustainable material. The effect …

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 …

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 …

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, …