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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Evaluation of prestress losses in an innovative prestressed precast pavement system

Davis, Brent M. January 2006 (has links)
Thesis (M.S.) University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 22, 2007) Includes bibliographical references.
62

Threaded rod continuity system for precast prestressed girder bridges

Wang, Ning. January 1900 (has links)
Thesis (Ph.D.)--University of Nebraska-Lincoln, 2006. / Title from title screen (site viewed May 23, 2007). PDF text: v, 326 p. : ill. (some col.) ; 3.85Mb UMI publication number: AAT 3237557. Includes bibliographical references. Also available in microfilm and microfiche formats.
63

2-D non-linear seismic analysis of one-storey eccentric precast concrete buildings

Parmar, Surinder Singh January 1987 (has links)
Investigations into the behaviour of precast buildings under earthquake loading have shown that the connections are likely to be the weakest link in a pre-cast structure, and the stability of the structure under earthquake loading depends upon the strength & stability of these connections. A 2-dimensional non-linear dynamic analysis of a one storey box-type pre-cast buildings is presented. The shear walls in the buildings are modelled by linear springs, the properties of which depend upon the connections connecting the rigid panels of the shear walls. To check the effectiveness of the NBCC code design, computer studies have been made on a box-type building statically designed for different eccentricities. The strength of the shear walls was calculated assuming that each panel was a cantilever fixed at the base with dowel bars providing the flexural steel. To make the building survive a major earthquake, we need dowel connections that can take 5mm to 6mm elongation which can be easily accommodated. Studies have also shown that under the action of an earthquake, the response of a highly unsymmetrical building will not be very different from that of a symmetric building as long as the building is properly designed using the NBCC code provisions for earthquake loading. It has also been shown that the NBCC code design eccentricity equation is somewhat conservative in calculating the design eccentricity and that a small change in the stiffness of walls perpendicular to the direction of earthquake has little effect on the response of the structures. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate
64

A cost study of an American precast panel system.

Moghadam, Hamid Reza. January 1978 (has links)
Thesis: M.S., Massachusetts Institute of Technology, Department of Civil Engineering, 1978 / Bibliography: p. 195-199. / M.S. / M.S. Massachusetts Institute of Technology, Department of Civil Engineering
65

Effects of Single Panel Replacement of a Full-Scale, Full-Depth, Precast Concrete Bridge Deck System

Perry, Jason Robert 01 August 2012 (has links)
The use of precast concrete deck panels is becoming increasingly popular for bridge construction and rehabilitation in the state of Utah and across the country. It allows for the use of full depth concrete deck panels but removes the long construction times of traditional cast-in-place methods. One of the challenges to the use of precast deck panels is the transverse deck panel joints that exist between the panels. These joints are unreinforced using traditional methods and therefore are the weakest section of the bridge. In many situations the joint will fail and water seeps through and can damage the bridge superstructure. Post-tensioning of precast decks has become the standard. The post-tensioning provides reinforcing through the joints, reducing the cracking that occurs. Additionally, the post-tensioning provides pressure along the joint and closes cracks that have occurred, therefore preventing water from leaking through to the superstructure and damaging it. The Utah Department of Transportation uses post-tensioning cables that run along the length of the bridge deck, applying pressure on the joints. One of the problems with using this method is it does not allow for the replacement of a single deck panel should the need arise. Utah State University has been researching a new post-tensioned connection that would allow for the replacement of a single deck panel. The “curved bolt” connection connects each deck panel to adjacent panels, providing reinforcement and post-tensioning along the joint. Laboratory testing was undertaken to investigate the effects of single panel bridge rehabilitation on the existing deck system.
66

CONSTRUCTABILITY ISSUES FOR CONNECTION BETWEEN SIMPLE SPAN PRECAST CONCRETE GIRDERS MADE CONTINUOUS

SHAH, RONAK YOGESHCHANDRA 11 October 2001 (has links)
No description available.
67

Steel-concrete composite construction with precast concrete hollow core floor

Lam, Dennis, Elliott, K.S., Nethercot, D.A. January 1999 (has links)
No / Precast concrete hollow core floor units (hcu) are widely used in all types of multistorey steel framed buildings where they bear onto the top flanges of universal beams. The steel beam is normally designed in bending, in isolation from the concrete slab, and no account is taken of the composite beam action available with the precast units. A program of combined experimental and numerical studies was undertaken that aimed at deciding on a suitable approach for the design of composite steel beams that utilize precast concrete hollow core slabs. The results show that the precast slabs may be used compositely with the steel beams in order to increase both flexural strength and stiffness at virtually no extra cost, except for the headed shear studs. For typical geometry and serial sizes, the composite beams were found to be twice as strong and three times as stiff as the equivalent isolated steel beam. The failure mode was ductile, and may have been controlled by the correct use of small quantities of tie steel and insitu infill concrete placed between the precast units.
68

A structural system for multi-story construction in prestressed-precast concrete

Alvarado, Eduardo E. January 1962 (has links)
It is the major purpose of this thesis to examine, through a practical engineering problem, the different aspects affecting the development of the structural concept. For this purpose, a prestressed-precast concrete structural system for multi-story construction is developed. After the introductory sections, the development of the structural system is explained in the third section. The section includes an analysis of the system, as well as a description of the individual component of the structure and their interaction. The analysis provides a corroboration of the adequacy of the concepts of the system. Illustration aid in the explanation of the problems involved. / Master of Science
69

Seismic performance assessment of reinforced concrete buildings with precast concrete floor systems : a thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy at the University of Cantrebury [i.e. Canterbury] /

Peng, Brian. January 1900 (has links)
Thesis (Ph. D.)--University of Canterbury, 2009. / Typescript (photocopy). "July 2009." Includes bibliographical references. Also available via the World Wide Web.
70

Recent Developments in the Use of Precast Concrete Units for Buildings in the United States and Iran

Farshchi, Khosrow Ebadi 24 August 1973 (has links)
The object of this study was to investigate the recent developments in the use of precast prestressed concrete members for buildings in the United States and Iran. In the United States, the study was concerned with developments in the usage of members such as slabs, wall panels, beams and columns. The latest technical and engineering reports, along with personal interviews, were used, and a number of case studies were conducted on recently built structures. The author also studied the newest developments in the precast concrete industry in Iran. A questionnaire was formulated in both Persian (native language of Iran) and English, and was sent to twelve of the largest precast concrete manufacturers in Iran. This study was extended to include the use of precast concrete members in alleviating Iran's housing shortage, which is one of the greatest problems facing the country today. From these studies the following observations have been made with respect to the United States: There is a vast variety of precast concrete units designed and manufactured in the country. The majority of precast concrete units in buildings are assembled by using simple connections. There has been great improvement in the quality of sealant materials. In the case studies conducted, it was evident that proper planning in design, production, transportation and erection of members were the major reasons in lowering the cost of precast concrete structures as compared to cast-in-place structures. The rapid increase in the use of precast concrete members is due to repetition of similar members, increase in strength and serviceability by prestressing, rapid construction, better quality control, improvement in handling and fire resistance qualities. In the case of Iran, the following observations have been made: The use of precast concrete members has increased rapidly in the last decade. Precast concrete construction, with proper sheer design, appears suitable in areas where there is stronger and more frequent earthquake occurrence. Precast concrete members are considered to be suitable for low-cost housing projects because of the availability of cement and steel reinforcement, an inadequate supply of wood and also because of the advantages of precast concrete mentioned above.

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