Engineering Commons^™

Experimental Investigation Of Cfrp Wrapped Square Non-Ductile Reinforced Concrete Columns, Hayder Lateef Al-Khafaji

Dissertations and Theses

The use of fiber-reinforced polymers (FRP) for retrofitting or strengthening deficient concrete columns noticeably increased in the past few decades. Plenty of research has been conducted on the behavior of FRP-strengthened circular concrete columns, but far less research has dealt with non-circular columns. In the current study, the focus was to investigate the behavior of square columns with low to medium grade concrete and low steel reinforcement that were strengthened using carbon fiber reinforced polymer (CFRP) wrap. In the experimental portion of this investigation, twelve short square reinforced concrete columns (5" x 5" in cross section and 12" high) were …

An Assessment Of Post-Encroachment Times For Bicycle-Vehicle Interactions Observed In The Field, A Driving Simulator, And In Traffic Simulation Models, Ali Razmpa

Dissertations and Theses

Most safety analysis is conducted using crash data. Surrogate safety measures, such as various time-based measures of time-to-collision can be related to crash potential and used to gain insight into the frequency and severity of crashes at a specific location. One of the most common and acknowledged measures is post-encroachment time (PET) which defines the time between vehicles occupying a conflicting space. While commonly used in studies of motor vehicle interactions, studies of PET for bicycle-vehicle interactions are few. In this research, the PET of bicycle-vehicle interactions measured in the field, a driving simulator, and in a micro-simulation are compared. …

Torsional Strengthening Of Reinforced Concrete Beams Using Cfrp Composites, Ranj Rafeeq

Dissertations and Theses

Few decades ago, there were no guidelines for torsion design of reinforced concrete (RC) beams. Hence, many existing beams in older buildings have a lack of adequate torsional strength since they were not properly designed for torsion. One way to regain/rehabilitate adequate torsional strength is through application of externally bonded carbon fiber reinforced polymers (CFRP). To date, American Concrete Institute (ACI) code, as well as other building codes, do not have recommendations or provisions for strengthening RC beams for torsion using fiber-reinforced polymer (FRP) composites due to the inexistence of conclusive experimental and analytical data. Of the very limited works …

Seismic Behavior And Design Of The Linked Column Steel Frame System For Rapid Return To Occupancy, Arlindo Pires Lopes

Dissertations and Theses

The Linked Column Frame (LCF) is a new brace-free lateral structural steel system intended for rapid return to occupancy performance level. LCF is more resilient under a design level earthquake than the conventional approaches. The structural system consists of moment frames for gravity that combines with closely spaced dual columns (LC) interconnected with bolted links for the lateral system. The LC links are sacrificial and intended to be replaced following a design level earthquake. The centerpiece of this work was a unique full-scale experiment using hybrid simulation testing; a combination of physical test of a critical sub-system tied to a …

Cyclic Loading Behavior Of Cfrp-Wrapped Non-Ductile Reinforced Concrete Beam-Column Joints, Ali S. H. Zerkane

Dissertations and Theses

Use of fiber reinforced polymer (FRP) material has been a good solution for many problems in many fields. FRP is available in different types (carbon and glass) and shapes (sheets, rods, and laminates). Civil engineers have used this material to overcome the weakness of concrete members that may have been caused by substandard design or due to changes in the load distribution or to correct the weakness of concrete structures over time specially those subjected to hostile weather conditions. The attachment of FRP material to concrete surfaces to promote the function of the concrete members within the frame system is …

Behavior Of Prestressed Concrete Beams With Cfrp Strands, Yasir Matloob Saeed

Dissertations and Theses

The high cost of repairing reinforced or prestressed concrete structures due to steel corrosion has driven engineers to look for solutions. Much research has been conducted over the last two decades to evaluate the use of Fiber Reinforced Polymers (FRPs) in concrete structures. Structural engineering researchers have been testing FRP to determine their usability instead of steel for strengthening existing reinforced concrete structures, reinforcing new concrete members, and for prestressed concrete applications. The high strength-to-weight ratio of FRP materials, especially Carbon FRP (CFRP), and their non-corrosive nature are probably the most attractive features of FRPs.

In this study, an experimental …

Acid-Base Equilibria In Organic-Solvent/Water Mixtures And Their Relevance To Gas/Particle Partitioning In The Atmosphere And In Tobacco Smoke, Julia Lynn Degagne

Dissertations and Theses

Acid-base equilibria in organic particulate matter (PM) are poorly understood, but have important implications for air quality and public health. First, acid-base reactions in organic particulate matter affect the gas/particle partitioning of organic compounds in the atmosphere, and these processes are not currently represented in atmospheric and climate change models. Second, the acid-base balance of tobacco smoke affects the amount of nicotine absorbed by the smoker, and a greater understanding of this balance would help to relate cigarette smoke composition to the addictive properties of cigarettes. This work presents data related to both air quality and tobacco smoke modeling.

The …

Mechanistic-Empirical Pavement Design Guide (Mepdg) Method Implemented To Estimate Damage In Flexible And Rigid Pavements, Tenzin Gusto

Dissertations and Theses

The implementation of the Empirical-Mechanistic Pavement Design Guide (MEPDG) method for flexible and rigid pavements requires numerous input parameters. Most of these parameters can be easily determined while some require best estimates that are usually extracted from available literature. This thesis identifies the most critical input parameters in terms of their effects on the damage of pavements and their influence on the determination of the number of corrective maintenance cycles to be performed during the design life of pavements. It was found that for flexible pavement, change in the average monthly temperature by as little as results in large differences …