<p>Premature debonding of externally bonded FRP laminate from retrofitted reinforced concrete (RC) members can lead to inefficient use of FRP and can limit the level of strength increase that can be achieved. In this investigation, novel carbon FRP anchors were used in an attempt to delay the onset of premature debonding and to achieve superior strength. Nine double shear tests were performed on small scale concrete prisms to determine the most suitable epoxy for bonding the anchors to the laminate and the concrete. One type of epoxy increased the ultimate load of the prism retrofitted with two anchors at each end of the laminate 83.7% over the control specimens without anchors. The second phase of the investigation consisted of testing six large scale T-beams with a 4500 mm span, 400 mm height and 500 mm flange width under four point bending. Two beams were tested without FRP reinforcement as control beams, one beam was tested with FRP only epoxy bonded and the remaining three beams were tested with the FRP epoxy bonded and anchored. One of the beams with 30 anchors exhibited a 46% increase in the debonding load over the beam without anchors while the FRP laminate attained a maximum strain equal to 80% of its ultimate strain capacity, a 94% increase over the beam strengthened with only epoxy bonded FRP. The results demonstrate the anchoring system’s effectiveness and a feasible way to efficiently utilize the FRP laminate.</p>

<p>Observations of structural damage following recent major earthquakes have indicated that ground motion characteristics have a significant effect on the damage of building structures. An analytical study is undertaken to investigate the effect of ground motion characteristics on the inelastic response of multistorey reinforced concrete frame structures and to evaluate the seismic performance of reinforced concrete frame structures designed in conformance with current Canadian seismic provisions. In addition, the possibility of using simplified analysis procedures to estimate inelastic response is studied for regular building frames subjected to different types of earthquake ground motions.</p> <p>An earthquake data set consisting of 45 horizontal components of strong motion records is selected and subdivided into three groups representative of seismic ground motions having low, intermediate, and high peak acceleration-to-velocity (A/V) ratios. This data set is analyzed to investigate the significance of the A/V ratio as a parameter to indicate the dynamic characteristics of earthquake ground motions resulting from different seismic environments. Four regular moment resisting reinforced concrete building frames having different fundamental periods are designed for combined gravity and seismic effects determined in accordance with the 1985 edition of the National Building Code of Canada (NBCC 1985). The structural members are proportioned and detailed to satisfy the requirements of the 1984 edition of the Canadian Concrete Code (CAN3-A23.3-H84). These four frames are used as structural models having very short, short, moderate, and long fundamental periods.</p> <p>To gain insight into the inelastic behaviour of the designed frames, the inelastic static responses of the frames to monotonically increased lateral loading are examined first. Following this inelastic static analysis, the inelastic dynamic responses of the frames to the three A/V groups of earthquake accelerograms are analyzed statistically. In addition, the elastic dynamic responses of the frames to the three A/V groups of earthquake records are obtained to provide a reference for the evaluation of the inelastic dynamic responses. In the course of the dynamic analyses, overall energy indices are defined for multistorey building frames and their numerical computation is implemented in a computer program.</p> <p>A simplified analysis procedure is proposed to estimate both overall and localized inelastic deformations for regular building frames. This simplified analysis procedure is evaluated based on a comparison of the inelastic deformational demands estimated from the procedure with the statistical results obtained from the inelastic dynamic analysis of the frames.</p> / Doctor of Philosophy (PhD)

A bridge approach is usually built to provide a smooth and safe transition for vehicles from the roadway pavement to the bridge structure. However, differential settlement between the roadway pavement resting on embankment fill and the bridge abutment built on more rigid foundation often creates a bump in the roadway. Previous work examined this issue at a microscopic level and presented new methods for eliminating or minimizing the effects at specific locations. This research studies the problem at a macroscopic level by determining methods to predict settlement severity to assist designers in developing remediation plans during project development to minimize the lifecycle costs of bridge bump repairs. The study is based on historic data from a wide range of Kentucky roads and bridges relating to bridge approach inspection and maintenance history. A macro method considering a combination of maintenance times, maintenance measures, and observed settlement was used to classify the differential settlement scale as minimal, moderate, and severe, corresponding to the approach performance status good, fair, and poor. A series of project characteristics influencing differential settlement were identified and used as parameters to develop a model to accurately predict settlement severity during preliminary design. Eighty-seven bridges with different settlement severities were collected as the first sample by conducting a survey of local bridge engineers in 12 transportation districts. Sample two was created by randomly selecting 600 bridges in the inspection history of bridges in Kentucky. Ordinal and/or multinomial logistic regression analyses were implemented to identify the relationships between the levels of differential settlement and the input variables. Two predictive models were developed. Prediction of bridge approach settlement can play an important role in selecting proper design, construction, and maintenance techniques and measures. The users can select one or two models to predict the approach settlement level for a new bridge or an existing bridge with different purposes. The significance of this study lies in its identification of parameters that had the most influence on the settlement severity at bridge ends, and how those parameters interacted in developing of a prediction model. The important parameters include geographic regions, approach age, average daily traffic (ADT), the use of approach slabs, and the foundation soil depth. The regression results indicate that the use of approach slabs can improve the performance of approaches on mitigating the problem caused by differential settlement. In addition, current practices regarding differential settlement prediction and mitigation were summarized by surveying the bridge engineers in 5 transportation districts.

Construction project performance and worker productivity are often tied to the availability and effective presentation of information, tools, materials, and equipment. While advancements in technology have improved much of the processes on a construction project, the medium of information dissemination at the construction work face has consistently relied on the use of two dimensional drawings and specifications. Industry initiatives are driving increased collaboration through three dimensional BIM (Building Information Modeling) models. However, the added dimension partially loses its effect when presented on a two dimensional computer monitor. Other computer forms of presentation intended for mobility (PDAs, laptops, and tablets) can be difficult to use in the field due to glare, durability in a harsh working environment, and the required skill level for effective use. Three dimensional (3D) physical printers now provide the capability to develop scaled and color models of a project directly from a BIM model. 3D physical printers represent a potential transformative change of providing engineering information to construction crews, but how to develop 3D models that leverage the cognitive benefits of viewing engineering information in a physical 3D form is unknown. The primary contribution to the overall body of knowledge of this dissertation is to scientifically examine the effect that different engineering information mediums have on an individual’s cognitive ability to effectively and accurately interpret spatial information. First, the author developed a robust scientific experiment for construction practitioners and students to complete. This experiment included outcomes measures on mental workload, cognitive demand, productivity, efficiency, demographics, and preferences. After collecting data, the author analyzed the outcomes through a series of statistical analyses to measure the differences between groups and quantify the affect and relationship among key variables. From the results, there are statistically significant improvements in productivity and efficiency of practitioners and students when using a physical model compared to two dimensional drawings and a three dimensional computer model. In addition, the average cognitive demand for a physical model was lower than the average cognitive demand for two dimensional drawings and three dimensional computer model.

The objective of the study was to map the structure of the construction engineering and management (CEM) discipline and its contents, trace its evolution, and to identify the most prevailing research areas in the discipline. The study entailed a review of the literature in construction engineering and management as well as two of the leading academic journals in the discipline, particularly a bibliometric study of the contents of the ASCE Journal of Management in Engineering (JME), as a case study of the CEM refereed journals. The JME's contents were investigated from its onset in 1985 until 2002. The results of the analysis show that 70% of the published papers focused on four main subjects: management and organization of the firm, project management, industry structure and environment, and management of personnel. Considerable changes occurred within the subjects with the emergence of new topics and the decline of others over the eighteen years of publication. The study also analyzed the use of keywords, research methods, and identified authors, and the concentration of knowledge. The JME is mainly concerned with the managerial aspects of engineering, while ASCE Journal of Construction Engineering and Management (JCEM) focuses more on construction and technical issues. Additional studies of the JCEM's contents should be conducted for a complete mapping of the discipline in the USA.

There are various situations in which electrical energy is desired but cannot by conveniently supplied. Since the days of Hienrich Hertz and Nikola Tesla, scientists have tried to solve this problem using different methods of wireless power transfer. Today, wireless power transfer has only been commercially demonstrated at small distances through use of induction. This thesis demonstrated the transfer of wireless power at relatively large distances through radio frequencies in the development of a prototype for a commercial product - a wireless household lamp.

This thesis looks at the capabilities of cutting thin webs on Wire EDM machines that are difficult or impossible to machine using conventional methods. Covered is an investigation of how different material and web thickness affect the capability of machining thin-walled parts. Five different metals are used for the test; Aluminum 6061 T6, Yellow Brass SS360, 420 Stainless Steel, D2 unheat-treated tool steel 25-30 RC, and D2 heat-treated tool steel 60-65 RC. The small parts were cut to a 6mm (0.2362 inch) height with six different wall thicknesses: 0.30mm (0.0118 inch), 0.25mm (0.0098 inch), 0.20mm (0.0078 inch), 0.15mm (0.0059 inch), 0.10mm (0.0039 inch), and 0.05mm (0.0020 inch). A Sodick AQ325L Wire EDM machine was utilized for testing. The methods employed during the study include the following: • Machine settings and offsets were limited to the default setting selected from the Sodick AQ325L database. • Two different pre-test cuts were taken on the material to check for web bending during the cutting process. • Hardness was tested for comparison of the web heights. This thesis shows that bending increased as webs became thinner and that bending occurred toward the wire as the second side of the web was cut. Bending does affect the height of the web. Physical properties of materials also impacted the height of the web with the hardest material staying intact during the cutting process. This study shows that two factors, physical properties of materials and web thickness, significantly affect cutting results for thin web parts.

Building Information Modeling (BIM) plays an important role in today's construction industry. Models are tools that help stakeholders communicate, visualize building geometry, perform trade coordination and clash detection among others. A less popular aspect of BIM that shows high potential is the quantity take-off (QTO) feature. Yet, its implementation among commercial general contractors (GC) has not received as much attention. The purpose of this study was to identify how the BIM QTO features were being implemented among commercial general contractors, what challenges they faced and how they worked to overcome those challenges. Through a three-step process including semi structured interviews with estimators, preconstruction, BIM and Virtual Design Construction (VDC) managers, valuable insights on the BIM QTO implementation state among general contractors were gathered and analyzed. Links between BIM QTO benefits, project design phases and delivery methods, software, training, leadership and jurisdictions were discussed. The data indicated that BIM QTO's benefits were best leveraged through early general contractor involvement, the adequate contract framework, trained BIM QTO estimators, and early and strategic communication between owners, designers and estimators. The conditions for increased efficiency were discussed along with the solutions to the common BIM-based QTO challenges.

Utility coordination is an exceedingly complex effort of managing, communicating, and facilitating the avoidance and relocation of utility facilities as needed for highway projects. Utility coordination occurs throughout the design and delivery of a project and best practices are used to make sure this occurs efficiently and in the best interest of the public, who are not only the taxpayers but also the ratepayers. Recent research has attempted to enhance utility location technology and procedures, instill frameworks and tools for utility coordination, and proceduralize risk management relative to utility coordination. However, research attempting to improve various aspects of utility coordination simultaneously has led to a lack of consensus on how to integrate these research efforts into an effective standard of practice. These is also not a standard of practice for quantifying utility related risks for transportation projects. This research will attempt to build consensus and contribute to the body of knowledge in this area of utility coordination by presenting an approach to assess the relative utility risks of a project and align current and new practices to minimize those risks. Through statistical analysis of historical project data regarding utility coordination schedules and costs for transportation projects in Kentucky, this study was able to produce a model that estimates utility related risk early in transportation project development. With input and evaluation by subject matter experts, utility coordination best practices were collected and aligned to utility risks on transportation projects. A decision support tool was developed to assist in the use of the mathematical utility risk model and the best practices associated with the varying risk levels. This research also finds that there are disparities among utility stakeholders on transportation projects in regard to the effectiveness or satisfaction with particular best practices. This finding presents the need for early involvement and collaborative utility coordination to select practices that ensure utility related issues on transportation projects are minimized. The research also presents that increased use of alternative contracting methods can pose significant challenges to utility coordination on transportation projects. This stems from the finding that utility coordination practices were not uniformly effective across these varying procurement methods. Furthermore, as Departments of Transportation continue to deal with resource issues, one of which being manpower within utility coordination, the use of consultants for utility coordination presents its own set of complexities. The research finds the best application of consult-led utility coordination is through third-part consultants specializing in utility coordination, those who have been state-specifically trained for utility coordination, and prequalified for utility coordination work.

The dangerous work environment in the construction industry and the inherent high risks associated with construction work make it the focus of safety training and regulations. Highway construction and maintenance has unique hazards but seemingly less directly applicable safety standards, regulations, and programs. Department of Transportation (DOT) employees working in highway maintenance are exposed to a variety of unique hazards specifically associated with their work and not relating to the adjacent traffic. Yet, highway construction and maintenance work has not received sufficient attention in terms of safety research and programs. The lack of safety training and education in highway construction and maintenance work leaves a significant portion of DOT employees prone to different work-related hazards that can be avoided with additional safety awareness. As part of the efforts of the Kentucky Transportation Cabinet (KYTC) to improve safety of their employees, the study describes the design, implementation, and evaluation of a pre-task safety briefing toolbox. By analyzing recordable incidents of KYTC maintenance employees and identifying frequent hazards present within their typical work operations and the causes behind the frequent incidents, the final product of design phase is a toolbox that is relatable and relevant to KYTC maintenance crews. The toolbox presents these hazards along with incidents causes and the appropriate safety practices to avoid or mitigate the associated risk. The goal of this safety toolbox is to improve safety awareness of KYTC maintenance crews. The second part of the study is a comprehensive systematic evaluation of the effectiveness of the toolbox. Three evaluation phases including reaction and knowledge evaluation, implementation evaluation, and behavior change evaluation were carried out to assess the effectiveness of the toolbox. With 22% improvement in workers safety knowledge, 23% improvement in workers hazards identification skills, and 33.24% increase in the likelihood of safe behavior, the results showed that pre-task safety toolbox talks can increase highway workers’ safety awareness, improve their hazards identification skills, and increase their safe behavior. In addition to serving an underserved audience of the construction workforce, this study contributes to the body of knowledge in different ways. First, it sheds the light on a significant underserved portion of construction workers and the unique hazards present in their work environment. Second, it presents the design, implementation, and evaluation of a data driven safety intervention that addresses the most frequent safety issues in highway maintenance operations. Finally, it presents an empirical trial to evaluate the effectiveness of a common practice used in the construction industry in a unique sector of the industry that has not received sufficient research efforts.