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Evaluation of Precast Portland Cement Concrete Panels for Airfield Pavement RepairsPriddy, Lucy Phillips 23 April 2014 (has links)
Both the identification and validation of expedient portland cement concrete (PCC) repair technologies have been the focus of the pavements research community for decades due to ever decreasing construction timelines. Precast concrete panel technology offers a potential repair alternative to conventional cast-in-place PCC because the panel is fully cured and has gained full strength prior to its use. This repaired surface may be trafficked immediately, thus eliminating the need for long curing durations required for conventional PCC. The literature reveals a number of precast PCC panel investigations in the past 50 years; however precast technology has only recently gained acceptance and increased use in the US for highway pavements. Furthermore, only limited information regarding performance of airfield applications is available. Following a review of the available technologies, an existing panel prototype was redesigned to allow for both single- and multiple-panel repairs. A series of various sized repairs were conducted in a full-scale airfield PCC test section. Results of accelerated testing indicated that precast panels were suitable for airfield repairs, withstanding between 5,000 and 10,000 passes of C-17 aircraft traffic prior to failure. Failure was due to spalling of the transverse doweled joints. The load transfer characteristics of the transverse joint were studied to determine if the joint load test could be used to predict failure. Results showed that the load transfer efficiency calculations from the joint load test data were not useful for predicting failure; however differential deflections could possibly be applied. Additionally, the practice of filling the joints with rapid-setting grout may have resulted in higher measurements of load transfer efficiency. To determine the stresses generated in the doweled joint, three-dimensional finite element analyses were conducted. Results indicated that the dowel diameter should be increased to reduce stresses and to improve repair performance. Finally, the precast repair technology was compared to other expedient repair techniques in terms of repair speed, performance, and cost. Compared to other methods, the precast panel repair alternative provided similar return-to-service timelines and traffic performance at a slightly higher cost. Costs can be minimized through modification to the panel design and by fabricating panels in a precast facility. Modifications to the system design and placement procedures are also recommended to improve the field performance of the panels. / Ph. D.
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Aplikace systému hospodaření s vozovkou (SHV) na silnicích II. a III. třídy Libereckého kraje / Aplication ofŽůrek, Jakub January 2020 (has links)
This master thesis deals with the pavement management system as a tool for a management and maintenance of the roads in the Liberec region. The aim is to collect road failures within the network pavement management system level on roads of 2nd and 3rd class. The resulting data will be used for evaluate pavement condition and make plans of pavement maintenance and rehabilitation in variants. Furthermore, the thesis deals with individual variants in the process of data evaluation when evaluating their suitability and accuracy. The theoretical part summarises the information needed to understand the functioning of the road management system, as well as a description of the software used to collect and subsequent work with the data. In the practical part are presented results of the thesis and moreover the questions arising from the goals set are answered.
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